cyanelle ribonuclease P complex

A ribonuclease P complex located in the cyanelle, where it catalyzes the 5' endonucleolytic cleavage of precursor tRNAs to yield mature tRNAs. The best characterized cyanelle ribonuclease P complex, from the alga Cyanophora paradoxa, contains a single RNA molecule that is necessary but not sufficient for catalysis, and several protein molecules.


urease complex

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A multiprotein nickel-containing complex that possesses urease activity (catalysis of the hydrolysis of urea to ammonia and carbon dioxide).


iNOS-S100A8/A9 complex

A protein complex capable of stimulus-inducible nitric-oxide synthase activity. S-nitrosylates cysteine residues in target proteins, a principal mechanism of nitric oxide (NO)-mediated signal transduction. In mammals consists of NOS2, S100A8 and S100A9. S100A9 acts both as an adaptor linking NOS2 to its target and as a transnitrosylase that transfers the nitric oxide moiety from NOS2 to its target, via its own S-nitrosylated cysteine.


Ddb1-Ckn1 complex

A heterodimeric nucleotide-excision repair complex that is involved in transcription-coupled repair. The subunits are known as Ddb1 and Ckn1 in S. pombe; Ddb1 contains a motif called the DDB-box that interacts with adaptor proteins for DDB1/cullin 4 ubiquitin ligases.


A protein complex which is capable of phosphatidylinositol transporter activity.


nuclear proteasome core complex, beta-subunit complex

The subunits forming the inner ring of the core complex of a proteasome located in the nucleus of a cell.


A protein complex that consists of an alphaE-beta7 integrin complex bound to E-cadherin.


histone H3-containing nucleosome

A complex comprised of DNA wound around a multisubunit core and associated proteins containing the histone H3, which forms the primary packing unit of DNA into higher order structures.


ERBB4:ERBB2 complex

A heterodimeric complex between the tyrosine kinase receptor ERBB2 and a ligand-activated receptor ERBB4. ERBB2, which does not bind any known ligand, is activated through formation of a heterodimer with another ligand-activated ERBB family member such as ERBB4.


myosin I complex

A myosin complex containing a class I myosin heavy chain and associated light chains; myosin I heavy chains are single-headed, possess tails of various lengths, and do not self-associate into bipolar filaments; myosin I complexes are involved in diverse processes related to membrane traffic and cell movement.


chloroplast ATP synthase complex

The protein complex that catalyzes the phosphorylation of ADP to ATP in chloroplasts.


integrin alphaD-beta2 complex

An integrin complex that comprises one alphaD subunit and one beta2 subunit.


SCF-Dia2/Pof3 ubiquitin ligase complex

An SCF ubiquitin ligase complex in which the F-box protein is Dia2 in S. cerevisiae (Pof3 in S. pombe).


Ddb1-Wdr21 complex

A heterodimeric nucleotide-excision repair complex that is involved in transcription-coupled repair. The subunits are known as Ddb1 and Wdr21 in S. pombe; Ddb1 contains a motif called the DDB-box that interacts with adaptor proteins for DDB1/cullin 4 ubiquitin ligases.


SBF transcription complex

A protein complex that binds to the Swi4/6 cell cycle box (SCB) promoter element, consensus sequence CRCGAAA, and activates transcription during the G1/S transition of the cell cycle. In Saccharomyces, the complex contains a heterodimer of the DNA binding protein Swi4p and the activator Swi6p, and is associated with additional proteins known as Whi5p and Msa1p.


alpha9-beta1 integrin-ADAM1 complex

A protein complex that consists of an alpha9-beta1 integrin complex bound to the transmembrane metallopeptidase ADAM1.


oligosaccharyltransferase II complex

An oligosaccharyltransferase (OST) complex that contains the seven polypeptides found in OST complex I, plus heterotrimeric Sec61alpha-beta-gamma. Of the three forms of mammalian OST complexes identified, the OSTII complex has intermediate affinity for ribosomes.


alphaV-beta3 integrin-CD98 complex

A protein complex that consists of an alphaV-beta3 integrin complex bound to the cell surface antigen CD98.


Hda-beta clamp complex

A protein complex involved in inactivating the function of DnaA and thereby preventing multiple events of replication initiation. In E. coli, this complex is composed of the beta clamp (DnaN) and Hda.


m7G(5')pppN diphosphatase complex

A homodimeric protein complex that catalyzes the reaction: 7-methylguanosine-5'-triphospho-5'-pholynucleotide + H20 = 7-methylguanosine-5'-phosphate + polynucleotide.


PKM2 protein kinase complex

A protein complex capable of phosphorylating a large number of protein targets. Contributes to cell proliferation under glycose starvation conditions. In human, the complex is present as a dimer.


A protein complex that consists of an alpha9-beta1 integrin complex bound to thrombospondin-1.


luminal surveillance complex

A multiprotein complex that recognizes ERAD-luminal misfolded substrates and brings them to the ubiquitination/extraction machinery. In yeast, this complex consists of Yos9p, Kar2p and Hrd3p proteins.


endosomal scaffold complex

A protein complex that contains MAPKSP1 (MP1, Map2k1ip1) and ROBLD3 (p14, Mapbpip), is anchored to late endosomes, and is involved in selective activation of the ERK1 in ERK/MAPK signaling.


pre-primosome complex

Any of the protein-DNA complexes that contain a DNA helicase and associated protein(s) at the origin of replication, and build up to assembling the core primosome. The associated protein(s) chaperone the helicase to the DNA, and assembly of the pre-primosome is essential for the initiation or restart of replication. Pre-primosome complexes lack a primase component.


myosin XVII complex

A myosin complex containing one or more class XVII myosin heavy chains and associated light chains.


DnaB-DnaC-Rep-PriC complex

A protein-DNA complex consisting of the helicase loading complex DnaB-DnaC, replication restart proteins Rep and PriC, and associated DNA. Involved in the restart of DNA replication after a stalled replication fork has been repaired.


plasma membrane proton-transporting ATP synthase complex, catalytic core F(1)

The catalytic sector of the plasma membrane hydrogen-transporting ATP synthase; it comprises the catalytic core and central stalk, and is peripherally associated with the plasma membrane when the entire ATP synthase is assembled. Examples of this component are found in Bacterial species.


neurotransmitter receptor complex

Any protein complex that is capable of functioning as a neurotransmitter receptor.


laminin-4 complex

A laminin complex composed of alpha2, beta2 and gamma1 polypeptide chains.


An enzyme complex that catalyzes the transfer of a phosphate from protein N(PI)-phosphohistidine to a sugar molecule. It is enzyme II of the phosphotransferase system.


BRCA1-Rad51 complex

A protein complex that contains BRCA1 and Rad 51, and is involved in the control of recombination and of genome integrity.


chloroplast thylakoid membrane protein complex

A protein complex that is part of a chloroplast thylakoid membrane.


Lid2 complex

A protein complex involved in regulation of chromatin remodeling. In Schizosaccharomyces the complex contains Lid2, Ash2, Jmj3, Snt2, and Sdc1.


DnaA-Dps complex

A protein complex that negatively regulates strand-opening at the origin of replication, thereby interfering with replication initiation. This complex is thought to be involved in the regulation of replication under oxidative stress conditions. In E. coli, this complex is composed of DnaA and Dps.


NADH dehydrogenase complex (plastoquinone)

An NADH dehydrogenase complex that catalyzes the transfer of electrons to plastoquinone. The complex is involved in the non-photochemical reduction of plastoquinones and the cyclic electron transport around photosystem I, and is found in plastid thylakoids.


alpha9-beta1 integrin-VEGF-A complex

A protein complex that consists of an alpha9-beta1 integrin complex bound to vascular endothelial growth factor A.


axonemal nexin link

A protein complex found in the axoneme of eukaryotic cilia and flagella. It forms interconnections between the microtubule outer doublets that surround the inner central pair of microtubules.


myosin XV complex

A myosin complex containing a class XV myosin heavy chain and associated light chains. Myosin XV is single headed, and has a large extension (1200aa) at the N-terminus of the motor domain, two IQ motifs and a tail with a similar domain structure to that of the tail of myosin VII.


A protein complex which is capable of pyrroline-5-carboxylate reductase activity.


chaperonin ATPase complex

Multisubunit protein complex with 2x7 (Type I, in most cells) or 2x8 (Type II, in Archaea) ATP-binding sites involved in maintaining an unfolded polypeptide structure before folding or to entry into mitochondria and chloroplasts.


myosin XI complex

A myosin complex containing a dimer of class XI myosin heavy chains and associated light chains. Myosin XI heavy chain sizes are similar in molecular structure to the class V myosins with 5 to 6 IQ motifs and tail regions with predicted coiled coil domains (forming dimeric molecules) and large C-terminal regions.


alpha5-beta5-fibronectin-SFRP2 complex

A protein complex that consists of an alpha5-beta5 integrin complex bound to fibronectin and secreted frizzled-related protein 2.


PSII associated light-harvesting complex II, peripheral complex, LHCIIb subcomplex

A pigment protein complex that forms part of the photosystem II associated light-harvesting complex II; contains two proteins (usually about 28 and 27 kDa), and may contain a third; peripherally located relative to other LHC polypeptides.


APC-IQGAP1-Rac1 complex

A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), the small GTPase Rac1, and the Rac1 and Cdc42 effector IQGAP1; may play a role in cytoskeleton organization and cell migration.


Pi Mi complex

A transcription factor complex composed of a homeodomain protein and the M-specific peptide Mi that acts at the regulatory region of genes required for the activation of meiosis.


chaperone-mediated autophagy translocation complex

A lysosomal membrane protein complex that enables the translocation of a target protein across the lysosomal membrane as part of chaperone-mediated autophagy.


mitochondrial proton-transporting ATP synthase, central stalk

One of two stalks that connect the catalytic core of the hydrogen-transporting ATP synthase to the mitochondrial membrane-associated F0 proteins; rotates within the catalytic core during catalysis.


Kelch-containing formin regulatory complex

A protein complex that regulates actin cable formation, polarized cell growth, and cytokinesis in a formin-dependent manner. In S. cerevisiae the complex is composed of Bud14p and two Kelch family proteins, Kel1p and Kel2p.


hydroxyisourate hydrolase complex

A hydrolase complex that converts 5-hydroxyisourate (HIU) to 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline. This is the second step of the three-step enzymatic reaction that degrades uric acid to (S)-allantoin.


INA complex

A protein complex located in the inner membrane of mitochondria that is involved in the assembly of the peripheral (or stator) stalk of the mitochondrial proton-transporting ATP synthase (also known as the F1F0 ATP synthase). In budding yeast, this complex includes Ina22p and Ina17p.


type I protein secretion system complex

A complex of three secretory proteins that carry out secretion in the type I secretion system: an inner membrane transport ATPase (termed ABC protein for ATP-binding cassette), which provides the energy for protein secretion; an outer membrane protein, which is exported via the sec pathway; and a membrane fusion protein, which is anchored in the inner membrane and spans the periplasmic space.


heterotetrameric ADPG pyrophosphorylase complex

A protein complex composed of four different subunits that possesses ADPG pyrophosphorylase activity. An example of this process is found in Mus musculus.


type II protein secretion system complex

A large protein complex, containing 12-15 subunits, that spans the cell envelope of Gram-negative bacteria and mediates the movement of proteins into the extracellular environment. The complex includes a component in the cytoplasm, an inner membrane subcomplex that reaches into the periplasmic compartment and a secretion pore in the outer membrane. Proteins using the Type II pathway are transported across the cytoplasmic membrane by the Sec or Tat complex.


3-isopropylmalate dehydratase complex

A heterodimeric enzyme complex composed of subunits leuC and leuD. Catalyzes the isomerization between 2-isopropylmalate and 3-isopropylmalate, via the formation of 2-isopropylmaleate.


sodium ion-transporting two-sector ATPase complex

A large protein complex that catalyzes the synthesis or hydrolysis of ATP by a rotational mechanism, coupled to the transport of sodium ions across a membrane. The complex comprises a membrane sector (F0 or V0) that carries out ion transport and a cytoplasmic compartment sector (F1 or V1) that catalyzes ATP synthesis or hydrolysis.


glideosome

A protein complex composed of at least GAP45 (gliding-associated protein), GAP50 and myosin heavy and light chains. Anchored via GAP50 to the inner membrane complex of motile and invasive forms of apicomplexan parasites and regulates parasite gliding motility and invasion of host cells.


HDA1 complex

A tetrameric histone deacetylase complex that contains a Class II deacetylase catalytic subunit. In S. cerevisiae it is composed of two Hda1p subunits along with Hda2p and Hda3p.


mitochondrial mRNA editing complex

An mRNA editing complex found in the mitochondrion. The best characterized example is that of Trypanosoma brucei, which catalyzes the insertion and deletion of uridylates.


axonemal heterotrimeric kinesin-II complex

A kinesin complex found in eukaryotic axonemes that contains two distinct plus end-directed kinesin motor proteins and at least one accessory subunit, and that functions in the anterograde transport of molecules (cargo) from the basal body to the distal tip of the axoneme.


basement membrane collagen trimer

Any collagen timer that is part of a basement membrane.


inhibin complex

Heterodimeric hormone composed of an inhibin alpha subunit complexed with either an inhibin beta-A subunit, to form inhibin A, or an inhibin beta-B subunit, to form inhibin B.


DASH complex

A large protein complex, containing around 8-10 subunits in yeast, including Duo1p, Dam1p, Dad1p and Ask1p. The complex forms part of the outer kinetochore, associates with microtubules when the kinetochore attaches to the spindle, and plays a role in spindle attachment, chromosome segregation and spindle stability.


RAD6-UBR2 ubiquitin ligase complex

A ubiquitin ligase complex consisting of RAD6 and UBR2 components. It may act in a quality control pathway for proteins synthesized on cytosolic ribosomes. The UBR2 component lacks sequence motifs required for N-end rule degradation.


FHL3-CREB complex

A protein complex that contains CREB and FHL3, and is involved in transcriptional regulation.


chromatophore ribulose bisphosphate carboxylase complex

A complex, located in the chromatophore, containing either both large and small subunits or just small subunits which carries out the activity of producing 3-phosphoglycerate from carbon dioxide and ribulose-1,5-bisphosphate.


collagen type XX trimer

A collagen homotrimer of alpha1(XX) chains.


classical-complement-pathway C3/C5 convertase complex

A heterodimeric protein complex that catalyzes the cleavage of complement components C3 and C5, and acts in the classical pathway of complement activation; consists of one monomer of C2a and one monomer of C4b; C2a is the catalytic subunit, but cannot catalyze cleavage alone.


starch utilization system complex

A bacterial cell envelope-associated multiprotein system, which binds and degrades starch.


methyl accepting chemotaxis protein complex

A transmembrane protein complex that consists of multiple methyl-accepting chemoreceptor protein subunits, a histidine kinase and a connector protein and which functions in the regulation of flagellar rotary motor activity in response to an external chemical stimulus.


transcription-coupled nucleotide-excision repair, DNA damage recognition complex

A protein complex that is capable of identifying lesions in DNA on the actively transcribed strand of the DNA duplex as well as a small subset of lesions not recognized by the general nucleotide-excision repair pathway. The wide range of substrate specificity suggests that the repair complex recognizes distortions in the DNA helix. It subsequently recruits a nucleotide-excision repair, preincision complex.


RNAi effector complex

Any protein complex that mediates the effects of small interfering RNAs on gene expression. Most known examples contain one or more members of the Argonaute family of proteins.


transcription factor TFIIIC1 complex

A transcription factor complex that forms part of the TFIIIC complex, observed in human. The complex is poorly characterized, but contains the 250-kDa form of HsBdp1, and is thought to include nuclear factor 1 (NF1). It stimulates binding by human TFIIIC2 and is required for transcription activity.


transforming growth factor beta activated kinase 1 complex

A protein complex that possesses protein kinase activity and activates the I-kappa B kinase complex (IKK) and mitogen-activated protein (MAP) kinases in response to TRAF6 signaling. It comprises the catalytic subunit TAK1 complexed to the regulatory subunits, termed TABs (TAK1-binding subunits).


nuclear proteasome regulatory particle, base subcomplex

The subunits of the regulatory particle that directly associate with the core complex of a proteasome located in the nucleus of a cell.


Vps55/Vps68 complex

A membrane-associated protein complex that is required for a late stage of endosomal transport. In budding yeast, this complex consists of Vps55p and Vps68p proteins.


DPS complex

A protein serine/threonine phosphatase complex that in S. pombe consists of the proteins Dis2, Ppn1, and Swd22.


PUMA-BCL-2 complex

A heterodimeric protein complex consisting of PUMA and BCL-2, members of the Bcl-2 family of anti- and proapoptotic regulators.


Lsm-containing SMN-Sm protein complex

An SMN-Sm protein complex formed by the association of the methylated Sm proteins B/B', D3, E, F, and G, and Lsm10 and Lsm11, with the SMN complex. This complex forms Sm cores on U7 snRNA.


PSI associated light-harvesting complex I, LHCIa subcomplex

A pigment protein complex that forms part of the photosystem I associated light-harvesting complex I; contains two proteins (usually about 24 and 21.5 kDa); has a fluorescence maximum between 680 and 690 nm.


laminin-522 complex

A laminin complex composed of alpha5, beta2 and gamma2 polypeptide chains.


DiaA complex

A homotetrameric protein complex consisting of a symmetrical pair of DiaA homodimers. Facilitates DnaA binding to the origin of replication during replication initiation.


trans-synaptic protein complex

A protein complex that spans the synaptic cleft and has parts in both the pre- and post-synaptic membranes.


exomer complex

A protein complex that forms a coat structure on vesicles involved in exocytosis of proteins from the trans-Golgi network to the cell surface; in Saccharomyces, the complex contains Chs5p, Chs6p, and Chs6p paralogues.


cobalamin transport complex

Protein complex facilitating ATP-dependent cobalamin (vitamin B12) transport through inner cell membrane (periplasm to cytoplasm) in Gram-negative bacteria. In E. coli the system is composed of a periplasmic cobalamin-binding protein (BtuF), an integral membrane homodimer, BtuC, and a cytoplasmic ATP-binding homodimer BtuD.


MAML3-RBP-Jkappa-ICN4 complex

A protein complex that consists of the intracellular domain of Notch4 (ICN4), the DNA-binding transcription factor RBP-Jkappa, and the transcriptional coactivator Mastermind-like-3 (MAML3); the complex is involved in transcriptional activation in response to Notch-mediated signaling.


methyl-tetrahydromethanopterin:coenzyme M methyltransferase complex

A protein complex consisted of eight polypeptides. This complex catalyzes the formation of methyl-coenzyme M and H4MPT from N5-methyl-H4MPT and CoM during methanogenesis.


methionyl glutamyl tRNA synthetase complex

A complex consisting of methionyl- and glutamyl-tRNA synthetases. The tRNA synthetases present in the complex bind to their cognate tRNAs more efficiently than they do as monomers.


glutamate-tRNA ligase complex

An enzyme complex that catalyzes the ligation of glutamate and tRNA(Glu) to form glutamyl-tRNA(Glu).


radial spoke base

The short portion of the radial spoke that is directly anchored to the A microtubule of an axonemal microtubule doublet.


interleukin-4 receptor complex

A protein complex that binds interleukin-4 (IL-4) and consists of an alpha chain that binds IL-4 with high affinity and a gamma common chain that also forms part of the interleukin-2 receptor.


iron-sulfur cluster transfer complex

A protein complex capable of catalyzing the transfer of an iron-sulfur (Fe-S) cluster from one compound (donor) to another (acceptor).


photosystem I reaction center

A photochemical system containing P700, the chlorophyll a dimer that functions as a primary electron donor. Functioning as a light-dependent plastocyanin-ferredoxin oxidoreductase, it transfers electrons from plastocyanin to ferredoxin.


fatty-acyl-CoA synthase complex

A protein complex that possesses fatty-acyl-CoA synthase activity.


B800-850 antenna complex

Protein-pigment complex that absorbs light at 800 and 850 nm; is peripherally associated to the bacterial reaction center; transfers excitation energy to the B875 antenna complex.


exoribonuclease complex

A protein complex which is capable of exoribonuclease activity.


glycine-tRNA ligase complex

A multimeric enzyme complex which, in bacteria, is usually a tetramer of two alpha and two beta chains and in eukaryotes, is usually a homodimer. Functions in the ligation of glycine and tRNA(Gly) to form glycyl-tRNA(Gly).


fumarate reductase complex

A membrane-bound flavoenzyme complex consisting of four subunits, A, B, C, and D. A and B comprise the membrane-extrinsic catalytic domain and C (InterPro:IPR003510; InterPro:IPR004224) and D (InterPro:IPR003418) link the catalytic centers to the electron-transport chain. This family consists of the 13 kDa hydrophobic subunit D. This component may be required to anchor the catalytic components of the fumarate reductase complex to the cytoplasmic membrane. Fumarate reductase couples the reduction of fumarate to succinate to the oxidation of quinol to quinone, in a reaction opposite to that catalyzed by the related complex II of the respiratory chain (succinate dehydrogenase-(ubiquinone)).


Pip2-Oaf1 complex

A heterodimeric complex consisting of Zn(2)Cys(6) containing transcription factors Pip2 and Oaf1. It binds to the oleate response element (ORE), found in the promoters of fatty acid-inducible genes in Saccharomyces where, in the presence of oleate this bound complex activates the transcription of genes encoding peroxisomal proteins.


RasGAP-Fyn-Lyn-Yes complex

A protein complex that consists of a GTPase activator protein (GAP) for Ras and three Src family protein tyrosine kinases, Fyn, Lyn and Yes. The complex is involved in signaling upon platelet activation.


A protein complex that consists of an alphaV-beta6 integrin complex bound to osteopontin.


E.F.G complex

A protein complex that comprises three core spliceosomal proteins, designated E, F, and G. Formation of the E.F.G complex is essential but not sufficient for the formation of a stable U1 snRNP complex.


nuclear pore linkers

A substructure of the nuclear pore complex (NPC) that serves to connect members of the central transport channel (composed of FG-nucleoporins) to the core scaffold (composed of the inner and outer NPC rings). In S. cerevisiae, the linkers are Nic96p and Nup82p. In vertebrates, they are Nup93 and Nup88. Components are arranged in 8-fold symmetrical 'spokes' around the central transport channel. Both linkers can be isolated in association with specific FG-nucleoporins, complexes that are sometimes referred to as the Nic96 complex (Nic96p-Nsp1p-Nup49p-Nup57p) and the Nup82 complex (Nup82p-Nup116p-Nup159p-Gle2p).


APC-IQGAP1-CLIP-170 complex

A protein complex that contains the tumor suppressor protein adenomatous polyposis coli (APC), the small GTPase Cdc42, and CLIP-170; may play a role in cytoskeleton organization and cell migration.


type IV site-specific deoxyribonuclease complex

A complex consisting of two proteins which acts as an endonuclease in DNA sequences containing a specific modified recognition site. Modifications may include methylation, hydroxymethylation, and glucosyl-hydroxymethylation.


heavy chain immunoglobulin complex

A protein complex composed of two identical immunoglobulin heavy chains of the IgNAR isotype held together by disulfide bonds and lacking immunoglobulin light chains.


alpha5-beta1 integrin-tissue transglutaminase complex

A protein complex that consists of an alpha5-beta1 integrin complex bound to tissue transglutaminase.


alpha6-beta4 integrin-CD151 complex

A protein complex that consists of an alpha6-beta4 integrin complex bound to the tetraspanin CD151.


IgD B cell receptor complex

An IgD immunoglobulin complex that is present in the plasma membrane of B cells and is composed of two identical immunoglobulin heavy chains of the IgD isotype and two identical immunoglobulin light chains and a signaling subunit, a heterodimer of the Ig-alpha and Ig-beta proteins.


replication inhibiting complex

A protein complex that inhibits multiple events of replication initiation during one replication cycle.


polyketide synthase complex

A protein complex that carries out enzymatic reactions involved in the biosynthesis of polyketides, any of a diverse group of natural products synthesized via linear poly-beta-ketones.


Grb2-SHP-2 complex

A protein complex that contains the receptor adaptor proteins Grb2 and SHP-2, and is involved signaling via the PDGFR signaling pathway.


CFTR-NHERF-ezrin complex

A protein complex that contains ezrin, Na+/H+ exchanger regulatory factor (NHERF, also called EBP50), and two copies of the cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR molecules interact with NHERF via their cytoplasmic tail domains; the complex is thought to link the CFTR channel to the actin cytoskeleton and contribute to the regulation of channel activity.


CSK-GAP-A.p62 complex

A protein complex that contains the protein-tyrosine kinase CSK and the GTPase-activating protein (GAP)-associated p62 (GAP-A.p62); may mediate translocation of proteins, including GAP and CSK, to membrane or cytoskeletal regions upon c-Src activation.


cytosolic tricarboxylic acid cycle enzyme complex

Any of the heteromeric enzymes, located in the cytosol, that act in the tricarboxylic acid (TCA) cycle.


cortical Lewy body

Cytoplasmic inclusion similar to a classical Lewy body but lacking a halo of protein fibrils.


nucleolar peripheral inclusion body

Inclusion bodies located at the nucleolar periphery where several nuclear factors are reversibly aggregated and sequestered during acute heat stress or starvation.


nematosome

Cytoplasmic, ball-like inclusion resembling a nucleolus and consisting of a convoluted network of electron-opaque strands embedded in a less dense matrix. It measures approximately 0.9 microns and lacks a limiting membrane. Its strands (diameter = 400-600 A) appear to be made of an entanglement of tightly packed filaments and particles approximately 25-50 A thick. Cytochemical studies suggest the presence of nonhistone proteins and some RNA. Usually only one such structure is present in a cell, and it appears to occur in most ganglion cells. Although they can be seen anywhere in the cell body, nematosomes are typically located in the perinuclear cytoplasm, where they are often associated with smooth-surfaced and coated vesicles.


skein-like inclusion

Intracytoplasmic filamentous structure frequently encountered in preparations immunostained for ubiquitin.


fibrillary inclusion

Cellular inclusion consisting of circular areas filled with fine slender filaments about 10 nanometers in diameter, delimited by a wall of varying complexity (either a single continuous membrane or a tubular network consisting of a fine filamentous material giving the wall a honeycomb appearance). Fibrillary inclusions are found in the cytoplasm of giant cells of Dieters in the lateral vestibular nucleus of the rat; similar structures have been described in the ventral cochlear nucleus, spinal cord, and substantia nigra.


complex laminated body

A cytoplasmic inclusion body found in some lateral geniculate neurons and composed of sheets of tubules (25 nm in diameter) separated by dense material (about 75 nm wide), which together with the tubules whorl give a structure resembling a fingerprint.


laminated body

Inclusion body characterized by regularly spaced sheets of tubules arranged in a whorl pattern resembling a fingerprint. Laminated bodies have been observed in neurons of the lateral geniculate nucleus.


Pick body

Cellular inclusion composed of numerous tau fibrils arranged in a disorderly array. Tau protein is a major component, though Pick bodies also contain ubiquitin, alpha-synuclein, and apolipoprotein E.


hyaline inclusion

A glass-like, pale intracellular inclusion.


cnida

A giant secretory organelle that comprises a bulb-shape capsule containing a coiled hollow tubule structure attached to it. A cnida defines the phylum Cnidaria.


central plaque of mitotic spindle pole body

One of three laminate structures that form the mitotic spindle pole body; the inner plaque is on the nuclear face of the spindle pole body.


central plaque of spindle pole body

One of three laminate structures that form the spindle pole body; the central plaque is embedded in the nuclear envelope.


cellular bud neck contractile ring

A contractile ring, i.e. a cytoskeletal structure composed of actin filaments and myosin, that forms beneath the plasma membrane at the mother-bud neck in mitotic cells that divide by budding in preparation for completing cytokinesis. An example of this structure is found in Saccharomyces cerevisiae.


extrahaustorial matrix

The space between the symbiont plasma membrane and the extrahaustorial membrane of the host.


glyoxysomal membrane

The lipid bilayer surrounding a glyoxysome.


glycosome membrane

The lipid bilayer surrounding a glycosome.


nucleus lagging edge

The area of a motile nucleus furthest from the direction of movement.


mannosome

A specialised tubular organelle, assembled in hexagonal bundles within an external membrane. Mannosomes are specific to molluscs and are thought to be involved in a general stress reaction.


extrinsic component of postsynaptic specialization membrane

The component of the postsynaptic specialization membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of presynaptic active zone membrane

The component of the presynaptic active zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of synaptic membrane

The component of the synaptic membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


extrinsic component of postsynaptic endocytic zone

The component of the postsynaptic endocytic zone membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


bacterial microcompartment

An organelle found in bacteria consisting of a proteinaceous coat containing metabolic enzymes whose purpose is the sequestration or concentration of metabolites and which has the appearance of a polygonal granule by electron microscopy.


protein aggregate center

Reversible aggregate of misfolded proteins and chaperones formed to shield thermosensitive proteins from degradation until conditions allow disaggregation and refolding.


crystalloid

A transient, cytoplasmic organelle found in Plasmodium species that resembles a cytoplasmic inclusion body and whose function is poorly understood. Crystalloids form in ookinetes and disappear after ookinete-to-oocyst transformation.


arciform density

An electron dense structure that anchors a synaptic ribbon to the presynaptic membrane.


monolayer-surrounded lipid storage body

A subcellular organelle of plant cells surrounded by 'half-unit' or a monolayer membrane instead of the more usual bilayer. The storage body has a droplet of triglyceride surrounded by a monolayer of phospholipids, interacting with the triglycerides and the hydrophilic head groups facing the cytosol, and containing major protein components called oleosins.


mitochondrial chromosome

A chromosome found in the mitochondrion of a eukaryotic cell.


Z chromosome

The sex chromosome present in both sexes of species in which the female is the heterogametic sex. Two copies of the Z chromosome are present in each somatic cell of males and one copy is present in females.


spectrosome

A germline specific spherical organelle, rich in membrane skeletal proteins. Precursor to the fusome.


ascus lipid droplet

Any particle of coalesced lipids in an ascus or ascospore. May include associated proteins.


chloroplast nucleoid

The region of a chloroplast to which the DNA is confined.


chloroplast stromal thylakoid

Unstacked thylakoids that connect the grana stacks through the stroma.


plastid ribosome

A ribosome contained within a plastid.


pyrenoid

A non-membrane-bounded organelle found within the chloroplasts of algae and hornworts; responsible for carbon dioxide fixation.


carboxysome

An organelle consisting of a proteinaceous coat and enzymes for the fixation of CO2. It augments the concentration of CO2 in the vicinity of RuBisCO to increase the efficiency of CO2 fixation under atmospheric conditions.


bacterial nucleoid

The region of a bacterial cell to which the DNA is confined.


goblet cell theca

A cup shaped specialization of the cytoskeleton that forms a thin layer located just below the apical mass of mature mucin secretory granules in the cytoplasm of goblet cells of the intestinal epithelium. It consists of an orderly network of intermediate filaments and microtubules. Microtubules are arranged vertically, like barrel staves, along the inner aspect of the theta. Intermediate filaments form two networks: an inner, basketlike network and an outer series of circumferential bundles resembling the hoops of a barrel.


synaptic ribbon

A non-membrane bound, electron dense structure associated that extends perpendicular to the presynaptic membrane in ribbon synapses. The ribbon's surface is studded with small particles to which synaptic vesicles tether via fine filaments. The tethered vesicles function as a pool, several fold greater than the docked pool available for fast release, which supports sustained release of vesicles. Synaptic ribbons may be plate like or spherical.


proplastid nucleoid

The region of a proplastid to which the DNA is confined.


chloroplast thylakoid

Sac-like membranous structures (cisternae) in a chloroplast combined into stacks (grana) and present singly in the stroma (stroma thylakoids or frets) as interconnections between grana. An example of this component is found in Arabidopsis thaliana.


active sex chromosome

A sex chromosome that has not been inactivated.


polytene chromosome chromocenter

A region at which the centric regions of polytene chromosomes are joined together.


cyanelle thylakoid

A thylakoid found in a cyanelle, which is a type of plastid found in certain algae. The cyanelle contains a photosynthetic membrane resembling that of cyanobacteria.


organellar ribosome

A ribosome contained within a subcellular membrane-bounded organelle.


prothylakoid

Underdeveloped thylakoids found in etioplasts, lacking competent photosynthetic membranes. Rapidly develop into mature thylakoids in the presence of light.


bacterial thylakoid

A thylakoid that is derived from and attached to, but not necessarily continuous with, the plasma membrane, and is not enclosed in a plastid. It bears the photosynthetic pigments in photosynthetic cyanobacteria.


gas vesicle

An intracellular non-membrane-bounded organelle; a hollow structure made of protein, which usually has the form of a cylindrical tube closed by conical end caps. By regulating their relative gas vesicle content, aquatic microbes are able to perform vertical migrations.


nucleolus-like body

A nuclear compartment containing significant amounts of non-nucleolar, spliceosomal components. It is commonly found in germinal vesicle (GV) stage oocytes, and is similar to both nucleoli and sphere organelles.


thylakoid

A membranous cellular structure that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the plasma membrane. In eukaryotes they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


organellar chromatophore thylakoid

A thylakoid located in an organellar chromatophore.


plastid thylakoid

Any thylakoid within a plastid.


plastid nucleoid

The region of a plastid to which the DNA is confined.


propanediol degradation polyhedral organelle

An organelle found in bacteria consisting of a proteinaceous coat containing enzymes for the degradation of 1,2-propanediol whose purpose is the protection of the rest of the cell from the toxic propionaldehyde product of the enzyme diol dehydratase.


chlorosome

A large enclosure of aggregated pigment, typically bacteriochlorophyll c (BChl c), that acts as a light-harvesting antenna structure and is characteristic of green photosynthetic bacteria (e.g. Chlorobiaceae). The BChl aggregates are organized into lamellar elements by pigment-pigment rather than pigment-protein interactions. Chlorosomes also contain BChl a, carotenoids, quinones, lipids, and proteins, and are attached to the cytoplasmic membrane via a BChl a-containing protein baseplate.


ventral disc

Specialized organelle found in Giardia species (trophozoite stage) and characterized by a spiral array of microtubules and microtubule-associated structures including dorsal microribbons and crossbridges. The edge of the ventral disc narrows into a lateral crest. The ventral disk mediates mechanical attachment of the trophozoite to the host's intestinal wall, and contains the contractile proteins actinin, alpha-actinin, myosin, and tropomyosin working towards contraction of the disk involved in adherence.


nematocyst

An organelle found in cnidoblast (nematoblast) cells. When matured, these stinging organelles store toxins and can deliver them when the cnidocil (a short extension of the cnidocyst) is stimulated by a prey or another stimulus.


W chromosome

The sex chromosome present in females of species in which the female is the heterogametic sex; generally, the sex chromosome that pairs with the Z chromosome in the heterogametic sex. The W chromosome is absent from the cells of males and present in one copy in the somatic cells of females.


blepharoplast

An intracellular non-membrane-bounded organelle found in multi-ciliated sperm cells of some primitive land plants, and consisting of many radially arranged ninefold symmetric cylinders. The blepharoplast is involved in de novo formation of multiple centrioles; it enlarges and then disintegrates into many procentrioles, which elongate and ultimately nucleate cilia on the surface of the sperm cell.


granal stacked thylakoid

Appressed thylakoid membranes that are part of a granum (stacked regions). A characteristic of these appressed regions is the preferential localization of photosystem II.


elaioplast

A leucoplast in which oil is stored.


mitotic nuclear bridge

A narrow constricted region of the nucleus that forms around the anaphase spindle during closed mitosis, and connects the main portions of the newly forming daughter nuclei.


host cell rough endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host rough ER has ribosomes adhering to the outer surface.


extrinsic component of external side of mycolate outer membrane

The component of mycolate membrane consisting of gene products and protein complexes that are loosely bound to its external surface, but not integrated into the hydrophobic region.


extrinsic component of mycolate outer membrane

The component of mycolate outer membrane consisting of gene products and protein complexes that are loosely bound to one of its surfaces, but not integrated into the hydrophobic region.


alae of collagen and cuticulin-based cuticle extracellular matrix

Raised, thickened cuticular ridges that run longitudinally, and in parallel, along the left and right sides of the animal. The alae lie above the hypodermal cells known as the lateral seam cells. In C. elegans, alae are produced in L1 larvae, dauer larvae and adult stage animals, where they consist of three, five, and three ridges of distinct morphology, respectively.


pnictogen molecular entity

A p-block molecular entity containing any pnictogen.


peptide

Amide derived from two or more amino carboxylic acid molecules (the same or different) by formation of a covalent bond from the carbonyl carbon of one to the nitrogen atom of another with formal loss of water. The term is usually applied to structures formed from alpha-amino acids, but it includes those derived from any amino carboxylic acid. X = OH, OR, NH2, NHR, etc.


primary amide

A derivative of an oxoacid RkE(=O)l(OH)m (l =/= 0) in which an acidic hydroxy group has been replaced by an amino or substituted amino group.


amide

An amide is a derivative of an oxoacid RkE(=O)l(OH)m (l =/= 0) in which an acidic hydroxy group has been replaced by an amino or substituted amino group.


carboxamide

An amide of a carboxylic acid, having the structure RC(=O)NR2. The term is used as a suffix in systematic name formation to denote the -C(=O)NH2 group including its carbon atom.


organonitrogen compound

Any heteroorganic entity containing at least one carbon-nitrogen bond.


organic amino compound

A compound formally derived from ammonia by replacing one, two or three hydrogen atoms by organyl groups.


host multivesicular body

A late endosome in which regions of the limiting host cell endosomal membrane invaginate to form internal vesicles; host membrane proteins that enter the internal vesicles are sequestered from the host cytoplasm.


host cell late endosome

A prelysosomal endocytic organelle differentiated from host early endosomes by lower lumenal pH and different protein composition. Host late endosomes are more spherical than early endosomes and are mostly juxtanuclear, being concentrated near the microtubule organizing center.


polar tube

A highly specialized structure unique to microsporidia that is required for host cell invasion. In the spore, the polar tube is connected at the anterior end, and then coils around the sporoplasm. Upon appropriate environmental stimulation, the polar tube rapidly discharges out of the spore, pierces a cell membrane and serves as a conduit for sporoplasm passage into the new host cell.


endospore coat

The layer in a bacterial endospore that lies under the exosporium, and is impermeable to many toxic molecules. The coat may also contain enzymes that are involved in endospore germination.


Yb body

A cytoplasmic part that appears as an electron-dense sphere of around 1.5 micron diameter containing Yb protein found in somatic cells of ovary and testis. There are one to two Yb bodies per cell.


leucoplast stroma

The space enclosed by the double membrane of a leucoplast.


linear element

A proteinaceous scaffold associated with fission yeast chromosomes during meiotic prophase. Linear elements consist of a protein complex, LinE, with four main structural components (Rec10, Rec25, Rec27, and Mug20 in S. pombe) associated with chromatin. The resulting structure is related to but not equivalent to the synaptonemal complex.


amyloplast inner membrane

The inner, i.e. lumen-facing, lipid bilayer of the amyloplast envelope; also faces the amyloplast stroma.


megagametophyte egg cell nucleus

The nucleus of a plant egg cell. This nucleus is found at the micropylar end of the embryo.


lignin network

An extracellular matrix part that consists of lignin in the form of a three-dimensional polymeric network. Lignins are complex racemic aromatic heteropolymers derived from a variety of phenylpropane monomers coupled together by an assortment of carbon-carbon and ether linkages. Lignin is crucial for structural integrity of the cell wall and stiffness and strength of the stem. In addition, lignin waterproofs the cell wall, enabling transport of water and solutes through the vascular system, and plays a role in protecting plants against pathogens.


hyphal septin band

A septin band, i.e. a diffuse ring composed of a series of septin bars running parallel to the long axis of the cell, located at the junction between the mother cell and the germ tube (hypha) of a fungal cell growing filamentously.


pilus shaft

The long, slender, mid section of a pilus.


lower tip-link density

An electron-dense plaque at the lower end of a stereocilia tip link that provides the anchor in the stereocilia membrane at the tip of the stereocilium from which the tip link rises.


sieve area

A pit-like area in the cell wall of a sieve element; contains pores lined with callose and occupied by strands of protoplasmic material that interconnect the protoplasts of contiguous sieve elements.


host cell PML body

A nuclear body that reacts against SP100 auto-antibodies (PML = promyelocytic leukemia) located within a cell of a host organism.


nucleoplasmic side of nuclear pore

The side of the nuclear pore complex (NPC) that faces the nucleoplasm.


left lateral basal body pair

Set of two basal bodies found in Giardia species (trophozoite stage). It comprises the anterior and ventral basal bodies located to the right of the left nucleus of the trophozoite when viewed dorsally.


host cell centrosome

A structure in a host cell comprised of a core structure (in most organisms, a pair of centrioles) and peripheral material from which a microtubule-based structure, such as a spindle apparatus, is organized. Centrosomes occur close to the nucleus during interphase in many eukaryotic cells, though in animal cells it changes continually during the cell-division cycle.


stereocilia tip link

A stereocilia link that is formed by a fine filament running more or less vertically upward from the tip of each shorter stereocilium to attach at a higher point on its adjacent taller neighbor. Tilting the bundle puts tension on the filaments, which pull on mechanically gated ion channels in the membrane of the stereocilia.


thorny excrescence

Large complex spine protruding from a dendrite. Each excrescence is formed by a cluster of spine heads.


postsynapse of neuromuscular junction

The postsynapse of a neuromuscular junction. In vertebrate muscles this includes the motor end-plate, consisting of postjunctional folds of the sarcolemma.


dinoflagellate sulcus

A cell surface furrow that occurs on the ventral side of a dinoflagellate cell. It partially houses the longitudinal flagellum. The sulcus intersects with the cingulum on the ventral side of a dinoflagellate cell.


cell surface furrow

A furrow that may be found on the cell surface. Examples include the cingulum and sulcus found in some dinoflagellates.


dinoflagellate cingulum

A cell surface furrow that wraps around a dinoflagellate cell; the transverse flagellum lies in it.


dinoflagellate sulcal notch

A dinoflagellate sulcus that extends all the way to the posterior end of the cell (also known as antapex). The presence of a sulcal notch makes the dinoflagellate hypocone appear bilobed.


dinoflagellate apical groove

A cell surface furrow (or groove) found on a dinoflagellate apex. It typically loops around the apex.


attachment organelle membrane

The lipid bilayer surrounding an attachment organelle. This is a region of the cell membrane facing the environment - in mycoplasma, part of the mycolate outer membrane.


host cell filopodium

Thin, stiff protrusion extended by the leading edge of a motile host cell such as a crawling fibroblast or amoeba, or an axonal growth cone; usually approximately 0.1 um wide, 5-10 um long, can be up to 50 um long in axon growth cones; contains a loose bundle of about 20 actin filaments oriented with their plus ends pointing outward.


host cell projection

A prolongation or process extending from a host cell, e.g. a flagellum or axon.


host cell uropod

A host cell membrane projection with related cytoskeletal components at the trailing edge of a cell in the process of migrating or being activated, found on the opposite side of the cell from the leading edge or immunological synapse, respectively.


T=219 icosahedral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=219 symmetry. T=219 icosahedral capsid is composed of 12 pentameric and 2180 hexameric capsomeres for a total of 13140 capsid proteins.


post-anaphase array microtubule end

Any microtubule end that is part of a post-anaphase array microtubule.


cytoplasmic microtubule minus-end

A microtubule minus end that is part of a cytoplasmic microtubule.


plasmodesmatal endoplasmic reticulum

Endoplasmic reticulum found in plasmodesmata, junctions connecting the cytoplasm of adjacent plant cells.


membrane stack

A configuration of endoplasmic reticulum (ER) found in Purkinje cells in the cerebellum and in axons in the lateral vestibular nucleus, consisting of parallel and interconnecting tubules whose outer surfaces are covered by particles or ringlike structures.


host intracellular part

Any constituent part of the living contents of a host cell; the matter contained within (but not including) the plasma membrane, usually taken to exclude large vacuoles and masses of secretory or ingested material. In eukaryotes it includes the nucleus and cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host chromosome

A structure composed of a very long molecule of DNA and associated proteins (e.g. histones) that carries hereditary information, occurring within a host cell.


host cell nucleus

A membrane-bounded organelle as it is found in the host cell in which chromosomes are housed and replicated. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell synaptic vesicle

A secretory organelle of a host cell, some 50 nm in diameter, of presynaptic nerve terminals; accumulates in high concentrations of neurotransmitters and secretes these into the synaptic cleft by fusion with the 'active zone' of the presynaptic plasma membrane.


Maurer's cleft

A disk-like structure that appears at the periphery of a red blood cell infected by an apicomplexan parasite, characterized by a translucent lumen and an electron-dense coat of variable thickness; often appears to be tethered to the host cell membrane by fibrous connections with the erythrocyte cytoskeleton.


viral replication complex

Specific locations and structures in the virus infected cell involved in replicating the viral genome.


host cell nucleolus

A small, dense body one or more of which are present in the nucleus of eukaryotic host cells.


host cell mitochondrial intermembrane space

The region between the inner and outer lipid bilayers of the host cell mitochondrial envelope.


host cell plastid

Any member of a family of organelles as found in the cytoplasm of host cells, which are membrane-bounded and contain DNA. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell nucleoplasm

That part of a host cell's nuclear content other than the chromosomes or the nucleolus. The host is the larger of the organisms involved in a symbiotic interaction.


host symbiosome

A double-enveloped cell compartment, composed of the endosymbiont with its plasmalemma (as inner envelope) and an outer envelope (the perisymbiontic membrane) derived from the host cell.


host cell endoplasmic reticulum lumen

The volume enclosed by the membranes of the host cell endoplasmic reticulum.


host cell synaptic vesicle membrane

The lipid bilayer surrounding a host synaptic vesicle.


host cell nuclear lamina

The fibrous, electron-dense layer lying on the nucleoplasmic side of the inner membrane of a host cell nucleus, composed of lamin filaments.


host cell peroxisome

A small host cell organelle enclosed by a single membrane, and found in most eukaryotic cells. Contains peroxidases and other enzymes involved in a variety of metabolic processes including free radical detoxification, lipid catabolism and biosynthesis, and hydrogen peroxide metabolism.


host cell endosome lumen

The volume enclosed by the membranes of the host cell endosome.


host cell mitochondrion

A semiautonomous, self replicating organelle as found in host cells that occurs in varying numbers, shapes, and sizes in the cell cytoplasm. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell perinuclear region of cytoplasm

The host cell cytoplasm situated near, or occurring around, the host nucleus.


host thylakoid membrane

The pigmented membrane of any host thylakoid.


host cell cytoplasmic vesicle

A vesicle formed of membrane or protein, found in the cytoplasm of a host cell.


host cell lysosome

A small lytic vacuole that has cell cycle-independent morphology and is found in most host animal cells and that contains a variety of hydrolases, most of which have their maximal activities in the pH range 5-6. The contained enzymes display latency if properly isolated. About 40 different lysosomal hydrolases are known and host cell lysosomes have a great variety of morphologies and functions.


host cell nuclear part

Any constituent part of a host cell's nucleus, a membrane-bounded organelle of eukaryotic cells in which chromosomes are housed and replicated. The host is the larger of the organisms involved in a symbiotic interaction.


host cell lipid droplet

Any particle of coalesced lipids in the cytoplasm of a host cell. May include associated proteins.


host cell Cajal body

A class of nuclear body in the eukaryotic host cell, first seen after silver staining by Ramon y Cajal in 1903, enriched in small nuclear ribonucleoproteins, and certain general RNA polymerase II transcription factors; ultrastructurally, they appear as a tangle of coiled, electron-dense threads roughly 0.5 micrometers in diameter; involved in aspects of snRNP biogenesis; the protein coilin serves as a marker for Cajal bodies. Some argue that Cajal bodies are the sites for preassembly of transcriptosomes, unitary particles involved in transcription and processing of RNA. The host is the larger of the organisms involved in a symbiotic interaction.


host intracellular organelle

Organized structure of distinctive morphology and function, occurring within the host cell. Includes the nucleus, mitochondria, plastids, vacuoles, vesicles, ribosomes and the cytoskeleton. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell smooth endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host smooth ER has no ribosomes adhering to the outer surface.


host cell mitochondrial envelope

The double lipid bilayer enclosing the host cell mitochondrion and separating its contents from the host cell cytoplasm; includes the intermembrane space.


symbiont-containing vacuole

Membrane-bounded vacuole within a host cell in which a symbiont organism resides. The vacuole membrane is derived from both the host and symbiont.


host cytoskeleton

A cellular structure that forms the internal framework of eukaryotic and prokaryotic host cells. The cytoskeleton includes intermediate filaments, microfilaments, microtubules, the microtrabecular lattice, and other structures characterized by a polymeric filamentous nature and long-range order within the cell. The various elements of the cytoskeleton not only serve in the maintenance of cellular shape but also have roles in other cellular functions, including cellular movement, cell division, endocytosis, and movement of organelles.


host cell cytoplasmic vesicle membrane

The lipid bilayer surrounding a host cell cytoplasmic vesicle.


host cell endosome

A membrane-bounded organelle that carries materials newly ingested by endocytosis. It passes many of the materials to host cell lysosomes for degradation.


host cell nuclear matrix

The dense fibrillar network lying on the inner side of the host nuclear membrane.


double membrane vesicle viral factory lumen

The volume surrounded by the inner membrane of a double membrane vesicle viral factory.


host cell cytoplasm part

Any constituent part of the host cell cytoplasm, all of the contents of a cell excluding the plasma membrane and nucleus, but including other subcellular structures. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host cell endoplasmic reticulum

The irregular network of unit membranes, visible only by electron microscopy, that occurs in the host cell cytoplasm of many eukaryotic cells. The membranes form a complex meshwork of tubular channels, which are often expanded into slitlike cavities called cisternae. The host ER takes two forms, rough (or granular), with ribosomes adhering to the outer surface, and smooth (with no ribosomes attached).


host cell cytosol

The part of the host cell cytoplasm that does not contain organelles but which does contain other particulate matter, such as protein complexes.


host cell viral nucleoid

The region of a host cell that contains the viral genome.


host intracellular membrane-bounded organelle

Organized structure of distinctive morphology and function, as found in host cells, bounded by a single or double lipid bilayer membrane and occurring within the cell. Includes the nucleus, mitochondria, plastids, vacuoles, and vesicles. Excludes the plasma membrane. The host is defined as the larger of the organisms involved in a symbiotic interaction.


host thylakoid

A membranous cellular structure within the host cell that bears the photosynthetic pigments in plants, algae, and cyanobacteria. In cyanobacteria thylakoids are of various shapes and are attached to, or continuous with, the host plasma membrane. In eukaryotic host cells they are flattened, membrane-bounded disk-like structures located in the chloroplasts; in the chloroplasts of higher plants the thylakoids form dense stacks called grana. Isolated thylakoid preparations can carry out photosynthetic electron transport and the associated phosphorylation.


T=pseudo3 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with pseudo T=3 symmetry. The T=pseudo3 capsid is composed of 12 pentameric and 20 hexameric capsomeres.


icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles; the subunits are arranged to form an icosahedron, a solid with 20 faces and 12 vertices. Icosahedral capsids have 12 pentamers plus 10(T-1) hexamers, where T is the triangulation number. Tobacco satellite necrosis virus has such a capsid structure.


T=147 icosahedral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=147 symmetry. T=147 icosahedral capsid is composed of 12 pentameric and 1460 hexameric capsomeres for a total of 8820 capsid proteins.


T=2 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=2 symmetry. The T=2 capsid is composed of 12 pentameric dimers.


T=25 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=25 symmetry. The T=25 capsid is composed of 12 pentameric and 240 hexameric capsomeres.


T=169 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=169 symmetry. T=169 icosahedral capsid is composed of 12 pentameric and 1680 hexameric capsomeres for a total of 10140 capsid proteins.


T=16 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=16 symmetry. The T=16 capsid is composed of 12 pentameric and 150 hexameric capsomeres.


T=13 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=13 symmetry. The T=13 capsid is composed of 12 pentameric and 120 hexameric capsomeres.


T=3 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=3 symmetry. The T=3 capsid is composed of 12 pentameric and 20 hexameric capsomeres.


T=7 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=7 symmetry. The T=7 capsid is composed of 12 pentameric and 60 hexameric capsomeres.


T=4 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=4 symmetry. The T=4 capsid is composed of 12 pentameric and 30 hexameric capsomeres.


T=1 icosahedral viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles where the subunits (capsomeres) are arranged to form an icosahedron with T=1 symmetry. The T=1 capsid is composed of 12 pentameric capsomeres.


postsynaptic specialization membrane of symmetric synapse

The membrane component of the postsynaptic specialization of a symmetic synapse. This is the region of the postsynaptic membrane in which the population of neurotransmitter receptors involved in synaptic transmission are concentrated.


nucleoid

The region of a virus, bacterial cell, mitochondrion or chloroplast to which the nucleic acid is confined.


type Ib terminal bouton

Terminal inflated portion of the axon of a glutamatergic neuron, containing the specialized apparatus necessary for the tonic release neurotransmitters that will induce the contraction of muscle. Type Ib terminal boutons are larger than type Is terminal boutons.


basal distal dendrite

Any dendrite in a dendritic tree that emerges near the basal pole of a neuron (e.g. in bipolar neurons, basal dendrites are either on the same side of the soma as the axon, or project toward the axon), and which is farthest away from the neuronal cell body (the soma).


cell wall-bounded periplasmic space

The region between the plasma membrane and the cell wall in organisms lacking an outer cell membrane such as yeast and Gram positive bacteria. The region is thinner than the equivalent in Gram negative bacteria.


monolayer-surrounded lipid storage body outer lipid monolayer

The single layer of phopholipids surrounding a lipid storage body.


left posteriolateral flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left posteriolateral basal body and extends cytoplasmically toward the cell posterior, marking the left anterior boundary of the lateral shield and the left lateral region of the funis before exiting at the left lateral region of the cell body.


hyphal tip

The end, or tip, of a fungal hypha, where polarized growth occurs during hyphal elongation.


nucleolar chromatin

The portion of nuclear chromatin associated with the nucleolus; includes the DNA encoding the ribosomal RNA.


nucleolus-associated heterochromatin

Dense particles of heterochromatin, consisting of a loosely twisted strand about 600 Angstrom thick, found associated with the nucleolus.


S bouton

Synaptic bouton found in the ventral horn of the spinal cord. S boutons range in diameter from 0.5 to 8 um and contain spherical synaptic vesicles.


smooth endoplasmic reticulum cisterna

A subcompartment of the smooth endoplasmic reticulum consisting of lumenal expansion into a flattened, disc-shaped cavity.


subrhabdomeral cisterna

A membrane-bounded compartment that is found at the base of the rhabdomere and contains stored calcium, InsP3 receptors and smooth endoplasmic reticulum Ca2+-ATPase.


sub-surface cisterna

Specialization of the hypolemmal cisterna consisting of either single profiles or closely apposed stacks of endoplasmic reticulum in which the lumen is obliterated, lying 10-20 nm beneath the plasma membrane.


hypolemmal cisterna

Specialized part of the smooth endoplasmic reticulum that closely underlies the plasma membrane, usually within 60 nm or closer.


ciliary pocket

Invagination of the plasma membrane from which a cilium (also called flagellum) protrudes.


eisosome membrane domain/MCC

A plasma membrane part that is composed of a furrow-like plasma membrane domain and associated integral transmembrane proteins.


host peribacteroid membrane

A host-derived membrane that surrounds one or more bacteroids (such as nitrogen-fixing bacteroids within legume root nodule cells).


transverse flagellum

A motile cilium found in dinoflagellates. It coils around the cell and provides the forward thrust for motility. It is often contained in a furrow called the cingulum, and emerges from a flagellar pore located in the cingulum.


sculpture element

The third layer of the sexine.


platelet glycocalyx

The carbohydrate rich layer at the outermost periphery of a platelet.


right tetrad

Set of four basal bodies found in Giardia species (trophozoite stage). It comprises the right lateral basal body pair and the right middle basal body pair (i.e. the anterior, ventral, caudal and posteriolateral basal bodies located to the left of the right nucleus of the trophozoite when viewed dorsally).


ventral disc supernumerary microtubule array

A partial left-handed spiral array of microtubules that lies generally dorsal to the main ventral disc microtubule array in Giardia species (trophozoite stage).


axonemal central pair

Part of the axoneme consisting of the inner two microtubule doublets of the 9+2 axoneme occurring in most motile cilia.


clathrin-coated endocytic vesicle lumen

The volume enclosed by the membrane of a clathrin-coated endocytic vesicle.


early phagosome lumen

The volume enclosed by the membrane of an eary phagosome.


host cell surface

The external part of the host cell wall and/or host plasma membrane.


host apoplast

The apoplast region surrounding a host plant cell. Plants may be described as having two major compartments: the living symplast and the non-living apoplast. The apoplast is external to the plasma membrane and includes cell walls, intercellular spaces and the lumen of dead structures such as xylem vessels. Water and solutes pass freely through it. The host is defined as the larger of the organisms involved in a symbiotic interaction.


left ventral basal body

Any ciliary basal body that is part of a left ventral flagellum found in Giardia species (trophozoite stage).


acellular membrane

biolink:AnatomicalEntity biolink:OrganismalEntity biolink:BiologicalEntity biolink:NamedThing biolink:PhysicalEssence biolink:SubjectOfInvestigation biolink:ThingWithTaxon biolink:PhysicalEssenceOrOccurrent

An acellular anatomical structure that is the bounding layer of a anatomical structure.


organic molecular entity

Any molecular entity that contains carbon.


heteroorganic entity

A heteroorganic entity is an organic molecular entity in which carbon atoms or organic groups are bonded directly to one or more heteroatoms.


organochalcogen compound

An organochalcogen compound is a compound containing at least one carbon-chalcogen bond.


organooxygen compound

An organochalcogen compound containing at least one carbon-oxygen bond.


endospore-forming forespore

Portion of the cell formed during the process of bacterial sporulation that will ultimately become the core of the endospore. An endospore is a type of dormant cell that is resistant to adverse conditions.


inner layer of spore wall

Either of the two innermost layers of the spore wall, as described in Saccharomyces.


9+2 non-motile cilium

A non-motile cilium where the axoneme has a ring of nine outer microtubule doublets plus two central microtubules (and is therefore called a 9+2 axoneme).


granum

Distinct stack of lamellae seen within chloroplasts. Grana contain the pigments, electron transfer compounds, and enzymes essential to the light-dependent reactions of photosynthesis.


F bouton

Synaptic bouton found in the ventral horn of the spinal cord. F boutons range in diameter from 0.5 to 7 um and contain flattened or pleomorphic synaptic vesicles.


eisosome

A cell part that is composed of the eisosome membrane or MCC domain, a furrow-like plasma membrane sub-domain and associated integral transmembrane proteins, and the proteins (eisosome filaments) that form a scaffolding lattice on the cytoplasmic face. Eisosomes broadly affect overall plasma membrane organization.


Organized structure of distinctive morphology and function, not bounded by a lipid bilayer membrane and occurring outside the cell.


cellulosome

An extracellular multi-enzyme complex containing up to 11 different enzymes aligned on a non-catalytic scaffolding glycoprotein. Functions to hydrolyze cellulose.


mating projection base

The region where the mating projection meets the bulk of the cell, in unicellular fungi exposed to mating pheromone.


apoplast

The cell membranes and intracellular regions in a plant are connected through plasmodesmata, and plants may be described as having two major compartments: the living symplast and the non-living apoplast. The apoplast is external to the plasma membrane and includes cell walls, intercellular spaces and the lumen of dead structures such as xylem vessels. Water and solutes pass freely through it.


porous cell septum

A septum or cross wall which does not entirely span the space between two portions of cell wall and may contain a specialized central pore structure. A porous septum allows the movement of organelles and/or cytoplasm between compartments.


dolipore septum

A septum, or cross-wall, between two portions of a cell or hypha; contains a central pore around which the septum is swollen to form a barrel-shaped structure; pore is covered on each side of the septum by a septal pore cap (parenthosome).


host cell synapse

The junction between a nerve fiber of one host neuron and another host neuron or muscle fiber or glial cell; the site of interneuronal communication.


cellular bud neck septin structure

Any of a series of septin structures that are localized in the bud neck of a budding fungal cell during the cell cycle.


annular furrow extracellular matrix

The extracellular matrix part that is a regularly spaced indentation in the outer cortical layer of the cuticle. The pattern of annular furrows corresponds to sites of invaginations in hypodermal cell membranes that, in turn, correspond to submembranous regions where actin microfilament bundles assemble early in lethargus, the first phase of the molting cycle in which activity and feeding decline.


yolk granule

Discrete structures that partition the water-insoluble portion of the yolk of oocytes and ova, which may or may not be membrane enclosed.


symbiont-containing vacuolar membrane network

Tubular network of extensions from the symbiont-containing vacuole membrane that protrude into the host cytoplasm.


host cell plasma membrane

The plasma membrane surrounding a host cell.


pellicle

The structure enclosing certain parasite cells such as certain apicomplexa and Euglenozoa; consists of the cell membrane with its associated infrastructure of microtubules, microfilaments and other organelles.


dendritic tuft

The terminal specialization found in some types of dendrites which consists of numerous small terminal branches, giving the dendrite a tufted appearance.


peribacteroid fluid

The soluble material inside the peribacteroid membrane, but outside of the bacteroid, within a bacteroid-containing symbiosome.


spine synapse

A type of synapse occurring between an axon and a dendritic spine.


short microvillus layer

A layer of microvilli covering lymphocytes.


proximal convoluted tubule brush border

A brush border layer that is part of a proximal tubule in the kidney.


cellular bud scar

Crater-like ring of chitinous scar tissue located on the surface of the mother cell. It is formed after the newly emerged daughter cell separates thereby marking the site of cytokinesis and septation. The number of bud scars that accumulate on the surface of a cell is a useful determinant of replicative age.


host cell mitochondrial membrane

Either of the lipid bilayers that surround the host cell mitochondrion and form the host cell mitochondrial envelope.


host cell mitochondrial inner membrane

The inner, i.e. lumen-facing, lipid bilayer of the host cell mitochondrial envelope. It is highly folded to form cristae.


exopher

An extracellular vesicle that is approximately four microns in diameter, released by budding out of cells into the extracellular space, and hypothesized to be a mechanism for disposal of unwanted cellular material including protein aggregates and damaged organelles.


female germline ring canal outer rim

An electron opaque backbone of the insect ovarian ring canal that is a part of or adjacent to the plasma membrane. The outer rim is established as the cleavage furrow is arrested, and contains F-actin, anillin, glycoproteins and at least one a protein with a high content of phosphorylated tyrosine residues.


free sarcoplasmic reticulum membrane

The part of the sarcoplasmic reticulum membrane that contains calcium pumps and is devoted to calcium uptake. The free sarcoplasmic reticulum membrane consists of the longitudinal sarcoplasmic reticulum membrane and the non-junctional region of the terminal cisterna membrane.


filiform apparatus

A complex of cell wall invaginations in a synergid cell, similar to those in transfer cells.


endospore core

An intracellular part that represents the innermost portion of an endospore; the endospore core is dehydrated, enriched in dipicolinic acid and divalent cations, and metabolically inactive.


phagocytic cup lip

The tip or margin of the progressing circular lamella that engulfs a particle during phagocytosis. When the two lips of the cup fuse it is converted into a phagosome.


chlorosome envelope

The structure, composed of a monolayer of glycolipids with embedded proteins, that encloses the pigments and other contents of the chlorosome.


organelle-enclosing lipid monolayer

A lipid monolayer that surrounds and encloses an organelle.


microneme

A small, elongated secretory organelle that forms part of the apical complex, located along the main axis of an apicomplexan parasite cell within the extreme apical region and at the periphery under the inner membrane complex. Of the specialized secretory compartments identified in apicomplexans, micronemes discharge their contents first, during initial contact of the parasite's apical pole with the host cell surface. Micronemal proteins function during parasite attachment and penetration into the target cell.


magnetosome

A membrane-bound organelle that envelops particles of magnetic iron minerals in magnetotactic bacteria. Magnetosomes form linear chains that align along the cellular motility axis at midcell and function in bacterial navigation along the Earth's magnetic field. They are formed by invagination of the cell inner membrane; in some species they remain connected to the inner membrane, in others they pinch off to form independent intracellular vesicles.


p-block molecular entity

A main group molecular entity that contains one or more atoms of a p-block element.


chalcogen molecular entity

Any p-block molecular entity containing a chalcogen.


dinoflagellate epicone

The part of a dinoflagellate cell above the cingulum; also referred to as the anterior portion of a dinoflagellate cell. It is separated from the hypocone by the cingulum.


etioplast stroma

The space enclosed by the double membrane of an etioplast but excluding the prothylakoid space. It contains the etioplast DNA.


mating projection

The projection formed by unicellular fungi in response to mating pheromone.


ascus epiplasm

Ascus cytoplasm that is not packaged into ascospores.


phragmosome

A flattened membranous vesicle containing cell wall components.


eyespot apparatus

A small pigmented organelle used in single-celled organisms to detect light.


LYSP100-associated nuclear domain

A nuclear body that is enriched in the lymphoid cell-specific protein LYSp100B; LANDs are globular, electron-dense structures and are morphologically distinct from the annular structures characteristic of PML bodies.


omega speckle

A nucleoplasmic speckle distributed in the interchromatin space of cells in close proximity to chromatin. Omega speckles are distinct from interchromatin granules and contain heterogeneous nuclear RNA-binding proteins (hnRNPs).


nuclear dicing body

A small round nuclear body, measuring 0.2-0.8 microns in diameter that is diffusely distributed throughout the nucleoplasm. Several proteins known to be involved in miRNA processing have been localized to these structures. D-bodies are thought to be involved in primary-miRNA processing and/or storage/assembly of miRNA processing complexes.


sphere organelle

A nuclear body that is found in the germinal vesicles of amphibian oocytes, and consist of three major parts: a remarkably spherical body about 5-10 pm in diameter, smaller spherical or nearly spherical granules on the surface, and inclusions of various sizes that strongly resemble the surface granules. The parts of the sphere organelle have distinct compositions, including splicing snRNAs and proteins.


nuclear exosome focus

An nuclear body involved in nuclear mRNA surveilllance. Contains at least Mmi1, or an ortholog of it, and the nuclear exosome.


chromoplast stroma

The space enclosed by the double membrane of a chromoplast but excluding the photosynthetic material.


Golgi apparatus subcompartment

A compartment that consists of a lumen and an enclosing membrane, and is part of the Golgi apparatus.


apical proximal dendrite

The dendrite of the dendritic tree, which emerges near the apical pole of a neuron, and which is the closest to the cell body of the neuron (the soma).


helical viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles; the subunits are arranged to form a protein helix with the genetic material contained within. Tobacco mosaic virus has such a capsid structure.


right anterior flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It originates at the right anterior basal body, extends laterally through the cytoplasm, crosses the left anterior axoneme, and exits as a membrane-bound flagellum on the anterior right side of the cell.


germline ring canal

Germline specific intercellular bridge. During cyst formation in insects, ring canals interconnect the cells of the cyst, facilitating the passage of cytoplasmic components between cells.


female germline ring canal

An intercellular bridge that connects the germline cells of a female cyst.


male germline ring canal

An intercellular bridge that connects the germline cells of a male cyst.


vestibular calyx terminal

The giant, cup-shaped axon terminal of a vestibular afferent neuron, serving as a post-synaptic contact to a type I hair cell.


Herring body

The dilated terminal portions of neurosecretory axons constituting the hypothalamohypophyseal tract, found in close proximity to sinusoidal capillaries in the posterior pituitary. Herring bodies consist of aggregates of membrane-bound neurosecretory vesicles where oxytocin or antidiuretic hormone (ADH) are stored prior to release. Each Herring body also contains ATP and either neurophysin I or neurophysin II which bind to oxytocin and ADH, respectively.


P2 peroxisome

A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P2 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content; they are the least dense of the subforms observed.


oral apparatus

Complex basket- or funnel-like structure used by the cell to collect food and channel it to the cytostome; includes specialized sub-structures made up of closely-spaced cilia and underlying basal bodies and fibrillar systems.


cell trailing edge membrane

The portion of the plasma membrane surrounding the trailing edge of a motile cell.


fungal-type vacuole

A vacuole that has both lytic and storage functions. The fungal vacuole is a large, membrane-bounded organelle that functions as a reservoir for the storage of small molecules (including polyphosphate, amino acids, several divalent cations (e.g. calcium), other ions, and other small molecules) as well as being the primary compartment for degradation. It is an acidic compartment, containing an ensemble of acid hydrolases. At least in S. cerevisiae, there are indications that the morphology of the vacuole is variable and correlated with the cell cycle, with logarithmically growing cells having a multilobed, reticulated vacuole, while stationary phase cells contain a single large structure.


reservosome

A large membrane-bound endocytic organelle present only in members of the Schizotrypanum subgenus of the Trypanosoma genus and is defined as the site of storage of endocytosed macromolecules and lysosomal enzymes. It is found at the posterior end of epimastigote forms of Trypanosoma cruzi, but absent in amastigotes and trypomastigotes.


stigma papilla

A plant cell papilla that is part of a stigma papilla cell.


apical lamina of hyaline layer

A fibrous network that is part of the hyalin layer extracellular matrix. The apical lamina is thought to be principally composed of the glycoproteins fibropellins. This matrix has been found in echinoderms.


reservosome membrane

The lipid bilayer surrounding a reservosome.


left ventral flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left ventral basal body and exits the cell body proximally and dorsal to the ventral disc.


growth cone lamellipodium

A thin sheetlike process extended by the leading edge of an axonal or dendritic growth cone; contains a dense meshwork of actin filaments.


rod spherule

A specialized neuron projection which is the site of synaptic transmission produced by retinal rod cells. Rod spherules are small round enlargements of the axon (3-5 micrometers diameter) or even extensions of the cell body.


right posteriolateral flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right posteriolateral basal body and extends cytoplasmically toward the cell posterior, marking the right anterior boundary of the lateral shield and the right lateral region of the funis before exiting at the right lateral region of the cell body.


giant axon

Extremely large, unmyelinated axon found in invertebrates. Has high conduction speeds and is usually involved in panic or escape responses.


dendritic cell dendrite

A branched cellular projection (or cytoplasmic extension) that is extended from the surface of a dendritic immune cell, and which enables the cell to sample luminal pathogens and increase the surface area for antigen presentation to T cells.


rod telodendria

Rod telodendria are projections that originate from the rod pedicle and form gap junctions with other photoreceptors within the outer plexiform layer of the retina.


accessory outer segment

A cilium-like cell projection emanating from the inner segment and running alongside the outer segment of photoreceptors.


cone telodendria

Cone telodendria are projections that originate from the cone pedicle and form gap junctions with other photoreceptors within the outer plexiform layer of the retina.


muscle cell projection

A prolongation or process extending from a muscle cell. A muscle cell is a mature contractile cell, commonly known as a myocyte. This cell has as part of its cytoplasm myofibrils organized in various patterns.


cytoneme

A long, thin, polarized cell projection that contains actin and can extend for distances many times the diameter of the cell. Cytonemes represent extensions of cell cytoplasm and typically have a diameter of approximately 0.2um.


right ventral flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right ventral basal body and exits the cell body proximally and dorsal to the ventral disc.


pollen tube

A tubular cell projection that is part of a pollen tube cell and extends from a pollen grain.


right caudal flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the right caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


left anterior flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It originates at the left anterior basal body, extends laterally through the cytoplasm, crosses the right anterior axoneme, and exits as a membrane-bound flagellum on the anterior left side of the cell.


gemmule

Spine-like process found on some neurons, e.g., periglomerular cells of olfactory cortex.


podocyte primary projection

A cell projection originating from a renal glomerular podocyte and extending to the renal glomerular podocyte foot.


rhabdomere microvillus

Thin cylindrical membrane-covered projection on the surface of a rhabdomere.


left caudal flagellum

A cilium (also called flagellum) found in Giardia species (trophozoite stage). It is nucleated by the left caudal basal body, extending cytoplasmically and exiting at the posterior end of the cell body.


cell hair

A long, thin cell projection that contains F-actin and tubulin, with microtubules centrally located and F-actin peripherally located.


longitudinal flagellum

A motile cilium found in dinoflagellates. It trails the cell and acts as a steering rudder. It is often partially contained in a furrow called the sulcus, and emerges from a flagellar pore located in the sulcus.


telodendria

Telodendria are projections that originate from the axon pedicle and form gap junctions with other neurons.


basal proximal dendrite

Any dendrite in a dendritic tree that emerges near the basal pole of a neuron (e.g. in bipolar neurons, basal dendrites are either on the same side of the soma as the axon, or project toward the axon), and which is the closest to the cell body of the neuron (the soma).


rhabdomere

The specialized microvilli-containing organelle on the apical surfaces of a photoreceptor cell containing the visual pigment rhodopsin and most of the proteins involved in phototransduction.


dinoflagellate peduncle

A small, flexible, finger-like projection of cytoplasm containing an array of microtubles and located near the flagellar pores in some photosynthetic as well as nonphotosynthetic dinoflagellate species. Its functions are not fully understood, but it has been associated with feeding behavior (phagotrophy).


plastid

Any member of a family of organelles found in the cytoplasm of plants and some protists, which are membrane-bounded and contain DNA. Plant plastids develop from a common type, the proplastid.


phenyloplast

A chloroplast-derived plastid in which the solid form of phenol is stored.


chloroplast

A chlorophyll-containing plastid with thylakoids organized into grana and frets, or stroma thylakoids, and embedded in a stroma.


apicoplast

The plastid organelle found in apicomplexans.


etioplast

A plastid arrested in the development of chloroplasts from proplastids due to absence of light or low light conditions.


leucoplast

A colorless plastid involved in the synthesis of monoterpenes.


chromoplast

A plastid containing pigments other than chlorophyll, usually yellow and orange carotenoid pigments.


proteinoplast

A leucoplast in which protein is stored.


cyanelle

A plastid that contains unstacked, phycobilisome-bearing thylakoid membranes and is surrounded by a double membrane with a peptidoglycan layer in the intermembrane space between the two envelope membranes. Cyanelles are characteristic of algae in the class Glaucophyta, and may represent an ancestral form of plastid.


cell plate

The nascent cell membrane and cell wall structure that forms between two daughter nuclei near the center of a dividing plant cell. It develops at the equitorial region of the phragmoplast. It grows outwards to join with the lateral walls and form two daughter cells.


egg chorion

A protective, noncellular membrane that surrounds the eggs of various animals including insects and fish.


viral capsid

The protein coat that surrounds the infective nucleic acid in some virus particles. It comprises numerous regularly arranged subunits, or capsomeres.


primary lysosome

A lysosome before it has fused with a vesicle or vacuole.


ascospore-type prospore nucleus

Any nucleus that is part of a ascospore-type prospore.


coated membrane

A single or double lipid bilayer with any of several different proteinaceous coats that can associate with membranes. Membrane coats include those formed by clathrin plus an adaptor complex, the COPI and COPII complexes.


bacterial-type flagellum filament

The long (approximately 20 nm), thin external structure of the bacterial-type flagellum, which acts as a propeller.


dendritic spine origin

The part of the dendritic spine neck where the spine arises from the dendritic shaft.


archaeal-type flagellum

A non-membrane-bounded organelle superficially similar to a bacterial-type flagellum; they both consist of filaments extending outside the cell, and rotate to propel the cell, but the archaeal flagella (also called archaella) have a unique structure which lacks a central channel. Similar to bacterial type IV pilins, the archaeal flagellins (archaellins) are made with class 3 signal peptides and they are processed by a type IV prepilin peptidase-like enzyme. The archaellins are typically modified by the addition of N-linked glycans which are necessary for proper assembly and/or function.


cellular anatomical entity

A part of a cellular organism that is either an immaterial entity or a material entity with granularity above the level of a protein complex but below that of an anatomical system. Or, a substance produced by a cellular organism with granularity above the level of a protein complex.


ventral disc overlap zone

A region of the ventral disc of Giardia species (trophozoite stage) where two portions of the same array of microtubules overlap (the microtubule array makes a complete circle and overlaps on itself).


pollen tube tip

The region at growing end of the pollen tube cell, where polarized growth occurs.


extrachromosomal rDNA circle

Circular DNA molecules encoding ribosomal RNA that are replicated independently of chromosomal replication. These molecules originate in the chromosome but are excised and circularized, often by intramolecular homologous recombination between direct tandem repeats.


medial membrane band

A sterol-rich region of the plasma membrane which forms at the cell surface overlying the contractile ring and spreads into the invaginating plasma membrane surrounding the septum.


somatic portion of tanycyte

Portion of a tanycyte that lies within the ependyma and contains the nucleus. A tanycyte is a specialized elongated ventricular ependymal cell that has processes that extend to the outer, or pial, surface of the CNS.


subsynaptic reticulum

An elaborate tubulolamellar membrane system that underlies the postsynaptic cell membrane.


plant cell papilla

A cell projection that is a short, rounded projection from a plant epidermal cell.


tail portion of tanycyte

Elongated process of a tanycyte, devoid of cytoplasmic extensions, that courses through the hypothalamic nuclei to form small endfoot processes that terminate either on blood vessels or at the pial surface of the brain. A tanycyte is a specialized elongated ventricular ependymal cell.


bacterial-type flagellum basal body

One of the three major substructures of the bacterial-type flagellum, the basal body is embedded in the cell envelope (the plasma membrane, peptidoglycan cell wall, and, if one is present, the outer membrane); it houses the secretion apparatus that exports the more distal components and the flagellar motor.


yeast-form cell wall

The wall surrounding a cell of a dimorphic fungus growing in the single-cell budding yeast form, in contrast to the filamentous or hyphal form.


host cell plasmodesma

A fine cytoplasmic channel, found in all higher plants, that connects the cytoplasm of one host cell to that of an adjacent host cell.


contractile actin filament bundle

An actin filament bundle in which the filaments are loosely packed (approximately 30-60 nm apart) and arranged with opposing polarities; the loose packing allows myosin (usually myosin-II) to enter the bundle.


extrahaustorial membrane

The membrane surrounding the symbiont haustorium during symbiosis, derived from the host plasma membrane.


ectexine

The outer part of the exine, which stains positively with basic fuchsin in optical microscopy and has higher electron density in conventionally prepared TEM sections.


periphagosomal region of cytoplasm

Cytoplasm situated near, or occurring around, a phagosome.


actin body

An amorphous cytoskeletal structure consisting of aggregated actin filaments and associated proteins (including fibrin and capping protein) in which there is little or no actin filament turnover. In yeast (S. pombe and S. cerevisiae) these are found only in quiescent cells and are thought to serve as a reserve store of actin.


karyomere

A membrane-bound intermediate cleavage-stage structure of individual or groups of chromosomes that coalesces and fuses with other karyomeres to form a nucleus during interphase. Karyomere formation occurs in blastomeres undergoing rapid cell division.


actin tubule

A cellular structure, approximately 13 nm in diameter, consisting of three actin filaments bundled together.


old cell pole

The cell pole distal from the most recent cell division.


pathogen-containing vacuole membrane

Host-derived membrane of a pathogen-containing vacuole.


bacterial-type flagellum hook

The portion of the bacterial-type flagellum that connects the filament to the basal body.


new cell pole

The cell pole proximal to the most recent cell division.


thylakoid lumen

The volume enclosed by a thylakoid membrane.


mitotic actomyosin contractile ring, intermediate layer

The region of the mitotic actomyosin ring in between the proximal layer and the actin filament layer. This region contains the accessory protein network, some actin filaments and connections between the proximal layer and the actin filament layer.


hemicellulose network

Network composed of hemicelluloses; members of a class of plant cell wall polysaccharide that cannot be extracted from the wall by hot water or chelating agents, but can be extracted by aqueous alkali. Includes xylan, glucuronoxylan, arabinoxylan, arabinogalactan II, glucomannan, xyloglucan and galactomannan.


A membrane-bounded flattened sac that is formed during micropexophagy between the membrane tips of an engulfing vacuole, completing the engulfment and sequestration of peroxisomes from the cytosol, and forming a micropexophagic body within the lumen of the vacuole.


generative cell nucleus

The nucleus of the generative cell, a cell contained within the pollen grain that will divide to produce two haploid sperm cells.


P6 peroxisome

A subform of peroxisome that corresponds to an intermediate in a peroxisome assembly pathway, which operates by conversion of peroxisomal subforms in the direction P1, P2 -> P3 -> P4 -> P5 -> P6. P6 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content, and are equivalent to mature peroxisomes.


microtubule organizing center attachment site

A region of the nuclear envelope to which a microtubule organizing center (MTOC) attaches; protein complexes embedded in the nuclear envelope mediate direct or indirect linkages between the microtubule cytoskeleton and the nuclear envelope.


polyadic synapse

A synapse consisting of a single presynapse and multiple postsynapses. These postsynapses may come from the same cell of from different cells. Polyadic synapses are common in arthropod and nematode central nervous systems.


mating projection membrane

The portion of the plasma membrane surrounding a mating projection, the projection formed by unicellular fungi in response to mating pheromone.