Protein complex that carries out the reaction: ATP + H2O + K+(out) = ADP + phosphate + K+(in). It is a high affinity potassium uptake system. The E. coli complex consists of 4 proteins: KdpA is the potassium ion translocase, KdpB is the ATPase, and KdpC and KdpF seem to be involved in assembly and stabilization of the complex.
A heterodimeric protein complex formed of Spt4 and Spt5 proteins which is expressed in eukaryotes from yeast to man. DSIF is an inhibitory elongation factor that promotes RNA polymerase II transcriptional pausing, but can also stimulate transcriptional elongation under certain conditions, and may play a role in RNA processing via its physical association with mRNA capping enzymes.
A eukaryotically conserved protein complex that localizes to kinetochores in early mitosis, the spindle mid-zone in anaphase B and to the telophase midbody. It has been proposed that the passenger complex coordinates various events based on its location to different structures during the course of mitosis. Complex members include the BIR-domain-containing protein Survivin, Aurora kinase, INCENP and Borealin.
A histone deacetylase complex which deacetylates histones preferentially in promoter regions. Composed of a catalytic histone deacetylase subunit, an Sds-3 family protein, a SIN3 family co-repressor, a WD repeat protein, and a zf- PHD finger (Clr6, Sds3, Pst1, Prw1, Png2 in Schizosaccharomyces pombe; Rpd3p, Sin3p, Ume1p, Pho23p, Sap30p, Sds3p, Cti6p, Rxt2p, Rxt3p, Dep1p, Ume6p and Ash1p in Saccharomyces cerevisiae).
A multiprotein ATPase complex required for the efficient dislocation of ER-lumenal degradation substrates, and their subsequent proteolysis by the proteasome. In budding yeast, this complex includes Cdc48p, Npl4p and Ufd1p proteins. In mammals, this complex includes a hexamer of VCP/p97 (a cytosolic ATPase) and trimers of each of its cofactors UFD1L and NPL4 (NPLOC4) (e.g. a 6:3:3 stoichiometry).
Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host STAT (signal transducer and activator of transcription) activity. STATs are SH2 domain-containing proteins which lie downstream of many signaling receptors. Upon phosphorylation by JAKs, STAT proteins hetero- or homo-dimerize and translocate to the nucleus to activate transcription of target genes.
Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host STAT1 (signal transducer and activator of transcription-1) activity. STATs are SH2 domain-containing proteins which lie downstream of many signaling receptors. Upon phosphorylation by JAKs, STAT proteins hetero- or homo-dimerize and translocate to the nucleus to activate transcription of target genes.
Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host STAT2 (signal transducer and activator of transcription-2) activity. STATs are SH2 domain-containing proteins which lie downstream of many signaling receptors. Upon phosphorylation by JAKs, STAT proteins hetero- or homo-dimerize and translocate to the nucleus to activate transcription of target genes.
A protein complex that contains two proteins (know in several organisms, including Drosophila, as NXF1 and NXF2) and is required for the export of the majority of mRNAs from the nucleus to the cytoplasm; localized in the nucleoplasm and at both the nucleoplasmic and cytoplasmic faces of the nuclear pore complex; shuttles between the nucleus and the cytoplasm.
A process of exocytosis found in all eukaryotic cells, in which transport vesicles destined for the plasma membrane leave the trans-Golgi network in a steady stream. Upon exocytosis, the membrane proteins and lipids in these vesicles provide new components for the plasma membrane, and the soluble proteins inside the vesicles are released into the extracellular space.
Interacting selectively and non-covalently with a MADS box domain, a protein domain that encodes the DNA-binding MADS domain. The MADS domain binds to DNA sequences of high similarity to the motif CC[A/T]6GG termed the CArG-box. MADS-domain proteins are generally transcription factors. The length of the MADS-box is in the range of 168 to 180 base pairs.
Trilaminar structure extending perpendicularly into the cytoplasm along the length of ventral disc microtubules in Giardia species (trophozoite stage). Constituents of dorsal microribbons (also called dorsal ribbons or microribbons) include alpha-coiled-helix proteins approximately 29 to 38 kDa in size. These proteins line the edges of the microribbons but are not found in microtubules. Tubulins are not found in microribbons.
The initial, indirect interaction between a transport vesicle membrane and the membrane of the endoplasmic reticulum. This interaction is mediated by tethering factors (or complexes), which interact with both membranes. Interaction can occur via direct binding to membrane phospholipids or membrane proteins, or via binding to vesicle coat proteins. This process is distinct from and prior fusion.
A protein complex acting as ligand of the transforming growth factor beta receptor complex, typically a homodimer of any of the TFGbeta isoforms. The precursor of TGFbeta proteins is cleaved into mature TGFbeta and the latency-associated peptide (LAP), which remains non-covalently linked to mature TGFbeta rendering it inactive. TGFbeta is activated by dimerisation and dissociation of the LAP.
A histone deacetylase complex formed by the association of an HP1 protein with a SHREC complex. The SHREC2 complex is required for deacetylation of H3K14, and mediates transcriptional gene silencing by limiting RNA polymerase II access to heterochromatin. In fission yeast, the complex contains the SHREC subunits Clr1, Clr2, Clr3, and Mit1, and the HP1 protein Chp2.
A protein complex consisting of the pentameric maltose transporter complex bound to two enzyme IIA (EIIA) molecules. EIIA is a component of the glucose-specific phosphotransferase system that inhibits maltose transport from the periplasm to the cytoplasm. When EIIA-bound, the maltose transporter remains in the open, inward-facing conformation, which prevents binding of maltose-loaded maltose binding protein (MBP) to the transporter.
The ProVWX complex belongs to the family of ATP-binding cassette (ABC) transporter proteins complexes. It consists of a cytoplasmic ATPase subunit ProV, a transmembrane subunit ProW and a periplasmic binding protein ProX. It is capable of translocating a wide variety of solute (e.g. glycine betaine) across the plasma membrane and is activated under osmotic stress conditions.
A conserved, heteroheptameric, cytoplasmic protein complex composed of Lsm1, Lsm2, Lsm3, Lsm4, Lsm5, Lsm6, Lsm7, and Pat1, or orthologs thereof, that shows a strong binding preference for oligoadenylated RNAs over polyadenylated RNAs. May bind further associated proteins. Facilitates the deadenylation-dependent decapping of mRNA in the P-body thereby regulating mRNA decay and subsequent degradation by the 5' to 3' pathway.
A protein complex that catalyzes the deneddylation of proteins, including the cullin component of SCF ubiquitin E3 ligase; deneddylation increases the activity of cullin family ubiquitin ligases. The signalosome is involved in many regulatory process, including some which control development, in many species; also regulates photomorphogenesis in plants; in many species its subunits are highly similar to those of the proteasome.
The evolutionarily conserved CCR4-NOT complex is involved in several aspects of mRNA metabolism, including repression and activation of mRNA initiation, control of mRNA elongation, and the deadenylation and subsequent degradation of mRNA. In Saccharomyces the CCR4-NOT complex comprises a core complex of 9 proteins (Ccr4p, Caf1p, Caf40p, Caf130p, Not1p, Not2p, Not3p, Not4p, and Not5p), Caf4p, Caf16p, and several less well characterized proteins.
The initial, indirect interaction between a secretory vesicle membrane and a site of exocytosis in the plasma membrane. This interaction is mediated by tethering factors (or complexes), which interact with both membranes. Interaction can occur via direct binding to membrane phospholipids or membrane proteins, or via binding to vesicle coat proteins. This process is distinct from and prior to docking and fusion.
A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IB phosphoinositide 3-kinase (PI3K) subunit and an associated regulatory subunit that is larger than, and unrelated to, the p85 proteins present in class IA complexes. Class IB PI3Ks are stimulated by G-proteins and do not interact with the SH2-domain containing adaptors that bind to Class IA PI3Ks.
Interacting selectively and non-covalently with spectrin, a protein that is the major constituent of the erythrocyte cytoskeletal network. It associates with band 4.1 (see band protein) and actin to form the cytoskeletal superstructure of the erythrocyte plasma membrane. It is composed of nonhomologous chains, alpha and beta, which aggregate side-to-side in an antiparallel fashion to form dimers, tetramers, and higher polymers.
The retrograde movement of substances within the Golgi, mediated by COP I vesicles. Cis-Golgi vesicles are constantly moving forward through the Golgi stack by cisternal progression, eventually becoming trans-Golgi vesicles. They then selectively transport membrane and luminal proteins from the trans- to the medial-Golgi while leaving others behind in the trans-Golgi cisternae; similarly, they selectively move proteins from the medial- to the cis-Golgi.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class Ib protein complex. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell. Class Ib here refers to non-classical class I molecules, such as those of the HLA-E gene family.
The process in which an antigen-presenting cell expresses a peptide antigen of exogenous origin on its cell surface in association with an MHC class Ib protein complex. The peptide is typically a fragment of a larger exogenous protein which has been degraded within the cell. Class Ib here refers to non-classical class I molecules, such as those of the HLA-E gene family.
A class I phosphatidylinositol 3-kinase complex that possesses 1-phosphatidylinositol-4-phosphate 3-kinase activity; comprises a catalytic class IA phosphoinositide 3-kinase (PI3K) subunit and an associated SH2 domain-containing regulatory subunit that is a member of a family of related proteins often called p85 proteins. Through the interaction with the SH2-containing adaptor subunits, Class IA PI3K catalytic subunits are linked to tyrosine kinase signaling pathways.
The stabilization of the multiprotein complex involved in damage recognition, DNA helix unwinding, and endonucleolytic cleavage at the site of DNA damage as well as the unwound DNA. The stabilization of the protein-DNA complex ensures proper positioning of the preincision complex before the phosphodiester backbone of the damaged strand is cleaved 3' and 5' of the site of DNA damage.
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. P1 peroxisomes are distinguished from the other subforms on the bases of buoyant density and protein content; they contain fewer peroxisomal proteins than the other subforms.
A class of nuclear body measuring 20-25 nm in diameter and distributed throughout the interchromatin space, linked together by thin fibrils. They are believed to be storage centers for various snRNAs, snRNPs, serine/arginine-rich proteins and RNA polymerase II. A typical mammalian cell contains 25-50 clusters of interchromatin granules. Interchromatin granule clusters do not contain the heterogeneous nuclear RNA-binding proteins (hnRNPs).
The hydrolysis of a peptide bond or bonds within a ligand for the epidermal growth factor receptor, as part of protein maturation, the process leading to the attainment of the full functional capacity of a protein. In Drosophila for example, in the Golgi apparatus of the signal producing cell, Spitz is cleaved within its transmembrane domain to release a functional soluble extracellular fragment.
A cellular process involving delivery of a portion of the cytoplasm to lysosomes or to the plant or fungal vacuole that does not involve direct transport through the endocytic or vacuolar protein sorting (Vps) pathways. This process typically leads to degradation of the cargo; however, it can also be used to deliver resident proteins, such as in the cytoplasm-to-vacuole targeting (Cvt) pathway.
A protein complex that in its canonical form is composed of two identical immunoglobulin heavy chains and two identical immunoglobulin light chains, held together by disulfide bonds and sometimes complexed with additional proteins. An immunoglobulin complex may be embedded in the plasma membrane or present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.
Any process the modulates the frequency, rate or extent of chromatin assembly. Chromatin assembly is the assembly of DNA, histone proteins, and other associated proteins into chromatin structure, beginning with the formation of the basic unit, the nucleosome, followed by organization of the nucleosomes into higher order structures, ultimately giving rise to a complex organization of specific domains within the nucleus.
A protein complex that consists of two interferon regulatory proteins (IRFs); may be homodimeric or heterodimeric. The activation of a latent closed conformation of IRF in the cytoplasm is triggered by phosphorylation of Ser/Thr residues in a C-terminal region. Phosphorylation stimulates the C-terminal autoinhibitory domain to attain a highly extended conformation triggering dimerization through extensive contacts to a second subunit.
The perinucleolar compartment (PNC) is a subnuclear structure associated with, but structurally distinct from, the nucleolus. The PNC contains large amounts of the heterogeneous nuclear ribonucleoprotein complex (hnRNP) called hnRNP 1 (PTB). Many RNA binding proteins as well as RNA polymerase III transcripts are highly enriched in this compartment. PTB and pol III transcripts are required for the integrity of the PNC.
The entry of a non-enveloped virus into a host eukaryotic cell, following endocytosis, via permeabilization of the endosomal membrane by membrane penetration protein(s) associated with the viral capsid. In some cases, viral membrane-penetration protein require first to be activated to display its membrane penetrating activity. Activation can be due to receptor binding or the acidic pH of the endosomal lumen.
The initial, indirect interaction between a contractile vacuole membrane and a site of discharge in the plasma membrane. This interaction is mediated by tethering factors (or complexes), which interact with both membranes. Interaction can occur via direct binding to membrane phospholipids or membrane proteins, or via binding to vesicle coat proteins. This process is distinct from and prior to docking and fusion.
A G protein-coupled receptor complex that serves as a receptor for amylin polypeptide (AMY) and consists of a calcitonin receptor (CTR/CALCR) and a receptor activity-modifying protein (RAMP) 3. Amylin receptor complex 3 (AMY3) also serves as a receptor for the amyloid-beta complex. Ligand binding to AMY3 results in increased cytosolic calcium ion levels and in activation on multiple intracellular signalling pathways.
A tetrameric protein complex capable of acetyltransferase activity. It can catalyze the transfer of an acetyl group from acetyl-CoA to an acceptor residue on histone H-3, histone H-4, or on polyamines. The complex is also capable of acetylating certain small basic proteins. The two Hpa2 dimers that make up the tetramer are held together by interactions between the bound acetyl-CoA molecules.
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.
A protein complex formed between the N-terminus of the giant sarcomeric filament protein titin and the Z-disk ligand, telethonin. The complex is part of the Z-disk of the skeletal and cardiac sarcomere. Telethonin binding to titin might be essential for the initial assembly, stabilization and functional integrity of the titin filament, and hence important for muscle contraction relaxation in mature myofibrils.
A series of molecular signals that proceeds with an activated receptor promoting the exchange of GDP for GTP on the alpha-subunit of an associated heterotrimeric G-protein complex. The GTP-bound activated alpha-G-protein then dissociates from the beta- and gamma-subunits to further transmit the signal within the cell. The pathway begins with receptor-leukotriene interaction and ends with regulation of a downstream cellular process, e.g. transcription.
Interacting selectively and non-covalently with an HMG box domain, a protein domain that consists of three helices in an irregular array. HMG-box domains are found in one or more copies in HMG-box proteins, which form a large, diverse family involved in the regulation of DNA-dependent processes such as transcription, replication, and strand repair, all of which require the bending and unwinding of chromatin.
The aggregation, arrangement and bonding together of proteins and centromeric DNA molecules to form a centromeric protein-DNA complex. Includes the formation of the chromatin structures which form a platform for the kinetochore, and assembly of the kinetochore onto this specialized chromatin. In fission yeast and higher eukaryotes this process also includes the formation of heterochromatin at the outer repeat (pericentric) regions of the centromere.
A pentameric protein complex related to replication factor C, which loads a trimeric complex of checkpoint proteins (known as the checkpoint clamp or 9-1-1 complex) onto DNA at damage sites; functions in DNA damage cell cycle checkpoints. In Schizosaccharomyces pombe the subunits are known as Rad17, Rfc2, Rfc3, Rfc4, and Rfc5, while in Saccharomyces cerevisiae the subunits are known as Rad24p, Rfc2p, Rfc3p, Rfc4p, and Rfc5p.
A multiprotein kinetochore subcomplex that binds to centromeric chromatin and forms part of the inner kinetochore of a chromosome in the nucleus. It helps to recruit outer kinetochore subunits that will bind to microtubules. Nuclear localization arises in some organisms because the nuclear envelope is not broken down during mitosis. In S. cerevisiae, it consists of at least four proteins: Mtw1p, Nnf1p, Nsl1p, and Dsn1.
The progression of the hepaticobiliary system over time, from its formation to the mature structure. The hepaticobiliary system is responsible for metabolic and catabolic processing of small molecules absorbed from the blood or gut, hormones and serum proteins, detoxification, storage of glycogen, triglycerides, metals and lipid soluble vitamins and excretion of bile. Included are the synthesis of albumin, blood coagulation factors, complement, and specific binding proteins.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class I protein complex. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and becomes associated with the MHC class I molecule in an endolysosome. Class I here refers to classical class I molecules.
The aggregation, arrangement and bonding together of a set of components to form the oxygen evolving complex (OEC) of photosystem II on a thylakoid membrane. The OEC protects the calcium-4 manganese-5 oxide cluster which is bound to the D1 and CP43 proteins. The exact protein composition of the OEC varies between cyanobacteria and plants, and in plants consists of three extrinsic nuclear-encoded polypeptides: PsbO, PsbP and PsbQ.
A cell-cell junction in which: on the cytoplasmic surface of each interacting plasma membrane is a dense plaque composed of a mixture of intracellular anchor proteins; a bundle of keratin intermediate filaments is attached to the surface of each plaque; transmembrane adhesion proteins of the cadherin family bind to the plaques and interact through their extracellular domains to hold the adjacent membranes together by a Ca2+-dependent mechanism.
A myosin complex containing a class IX myosin heavy chain and associated light chains. Myosin IX is monomeric with a motor domain containing an N-terminal extension and an insert in the actin binding interface, followed by four to six IQ motifs and a tail region that contains a zinc binding motif and a domain with homology to GTPase activating proteins (GAPs) of the Rho family of G-proteins.
The initial, indirect interaction between a vesicle membrane and a membrane to which it is targeted for fusion. This interaction is mediated by tethering factors (or complexes), which interact with both membranes. Interaction can occur via direct binding to membrane phospholipids or membrane proteins, or via binding to vesicle coat proteins. This process is distinct from and prior to interaction between factors involved in fusion.
A protein complex responsible for the catalysis of the reaction: E1 + ubiquitin + ATP--> E1-ubiquitin + AMP + PPi, where the E1-ubiquitin linkage is a thioester bond between the C-terminal glycine of Ub and a sulfhydryl side group of an E1 cysteine residue. This is the first step in a cascade of reactions in which ubiquitin is ultimately added to a protein substrate.
An actin-rich cytoskeletal network located beneath the microvilli of the apical plasma membrane of polarized epithelial cells. In addition to actin filaments, the terminal web may contain actin-binding proteins, myosin motor proteins, and intermediate filaments. The terminal web can function as a contractile structure that influences the spatial distribution of microvilli as well as the development and morphogenesis of tissues containing polarized epithelial cells.
Interacting selectively and non-covalently with a C3HC4-type zinc finger domain of a protein. The C3HC4-type zinc finger is a variant of RING finger, is a cysteine-rich domain of 40 to 60 residues that coordinates two zinc ions, and has the consensus sequence: C-X2-C-X(9-39)-C-X(1-3)-H-X(2-3)-C-X2-C-X(4-48)-C-X2-C, where X is any amino acid. Many proteins containing a C3HC4-type RING finger play a key role in the ubiquitination pathway.
An system process carried out by any of the organs or tissues of the hepaticobiliary system. The hepaticobiliary system is responsible for metabolic and catabolic processing of small molecules absorbed from the blood or gut, hormones and serum proteins, detoxification, storage of glycogen, triglycerides, metals and lipid soluble vitamins and excretion of bile. Included are the synthesis of albumin, blood coagulation factors, complement, and specific binding proteins.
Area of the cilium (also called flagellum) where the basal body and the axoneme are anchored to the plasma membrane. The ciliary base encompasses the distal part of the basal body, transition fibers and transition zone and is structurally and functionally very distinct from the rest of the cilium. In this area proteins are sorted and filtered before entering the cilium, and many ciliary proteins localize specifically to this area.
Interacting selectively and non-covalently with an RNA polymerase II (Pol II) complex, typically composed of twelve subunits, and with another protein, macromolecule, or complex, permitting those molecules to function in a coordinated way in order to facilitate the aggregation, arrangement and bonding together of proteins on an RNA polymerase II promoter DNA to form the transcriptional preinitiation complex (PIC), the formation of which is a prerequisite for transcription by RNA polymerase.
The process in which an antigen-presenting cell expresses a peptide antigen of exogenous origin on its cell surface in association with an MHC class I protein complex following intracellular transport via a pathway not requiring TAP (transporter associated with antigen processing). The peptide is typically a fragment of a larger exogenous protein which has been degraded within the cell. Class I here refers to classical class I molecules.
Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host tapasin (TAP binding protein/TAPBP) activity. Tapasin is a type I transmembrane protein essential for the optimal expression of stable MHC class I molecules on the host cell surface. By inhibiting host tapasin activity, viruses can prevent presentation of their antigens at the cell surface, and thereby evade the host anti-viral immune response.
A ubiquitin ligase complex consisting of UBR1 and RAD6 components. It polyubiquitinates proteins containing non-acetylated N-terminal residues causing their subsequent degradation by the proteasome as part of the Ac/N-End Rule pathway. It recognizes non-acetylated N-terminal methionine if it is followed by a hydrophobic residue. Additionally, it acts in an N-end rule independent manner as a component of a novel quality control pathway for proteins synthesized on cytosolic ribosomes.
A protein complex consisting of Prp19 and associated proteins that is involved in the transition from the precatalytic spliceosome to the activated form that catalyzes step 1 of splicing, and which remains associated with the spliceosome through the second catalytic step. It is widely conserved, found in both yeast and mammals, though the exact composition varies. In S. cerevisiae, it contains Prp19p, Ntc20p, Snt309p, Isy1p, Syf2p, Cwc2p, Prp46p, Clf1p, Cef1p, and Syf1p.
Ejection by a non-enveloped prokaryotic virus of its genome into the host cytoplasm via a short tail ejection system consisting a central tube, the connector which attaches the tail to the phage capsid and releases inner core proteins. Upon binding to the host cell surface, the phage displays a tube-like extension of its short tail that penetrates both host membranes. This tail extension comes from the release of viral core proteins with channel forming properties.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class I protein complex following intracellular transport via an ER pathway. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and becomes associated with the MHC class I molecule in the ER. Class I here refers to classical class I molecules.
The process in which an antigen-presenting cell expresses lipid antigen in association with an MHC class Ib protein complex on its cell surface, including lipid extraction, degradation, and transport steps for the lipid antigen both prior to and following assembly with the MHC protein complex. The lipid antigen may originate from an endogenous or exogenous source of lipid. Class Ib here refers to non-classical class I molecules, such as those of the CD1 family.
A cytoplasm to vacuole targeting pathway that uses machinery common with autophagy. The Cvt vesicle is formed when the receptor protein, Atg19, binds to the complexes of the target protein (aminopeptidase or alpha-mannosidase homododecamers), forming the Cvt complex. Atg11 binds to Atg9 and transports the Cvt complex to the pre-autophagosome (PAS). The phagophore membrane expands around the Cvt complex (excluding bulk cytoplasm) forming the Cvt vesicle. This pathway is mostly observed in yeast.
A protein complex that contains four related proteins that have been implicated in several membrane-related processes, such as sorting of H+-translocating ATPases, endocytosis, ER-Golgi trafficking, vacuole fusion, vacuolar polyphosphate homeostasis and the microautophagic scission of vesicles into the vacuolar lumen. The complex is enriched at the vacuolar membrane, but also found in other cellular compartments, including the ER and the cell periphery. In Saccharomyces, the subunits are Vtc1p, Vtc2p, Vtc3p and Vtc4p.
A protein complex that consists of a homo- or heterodimer of members of a family of structurally related proteins that contain a conserved N-terminal region called the Rel homology domain (RHD). In the nucleus, NF-kappaB complexes act as transcription factors. In unstimulated cells, NF-kappaB dimers are sequestered in the cytoplasm by IkappaB monomers; signals that induce NF-kappaB activity cause degradation of IkappaB, allowing NF-kappaB dimers to translocate to the nucleus and induce gene expression.
The central substructure of the nuclear pore complex (NPC), through which nucleocytoplasmic transport of RNAs, proteins and small molecules occurs. The central transport channel is filled with FG-nucleoporins, which form a selective barrier and provide a series of binding sites for transporter proteins. Characterized S. cerevisiae FG-nucleoporins include Nup159p, Nup145Np, Nup116p, Nup100p, Nsp1p, Nup57p, Nup49p, Nup42p, Nup53p, Nup59p/Asm4p, Nup60p and Nup1. Characterized vertebrate FG-nucleoporins include Nup214, Nup98, Nup62, Nup54, Nup58/45, NLP1, and Nup153.
The transcription export (TREX) complex couples transcription elongation by RNA polymerase II to mRNA export. The complex associates with the polymerase and travels with it along the length of the transcribed gene. TREX is composed of the THO transcription elongation complex as well as other proteins that couple THO to mRNA export proteins. The TREX complex is known to be found in a wide range of eukaryotes, including S. cerevisiae and metazoans.
A protein-containing complex that monoubiquitinates histone H2A on K119, thus it facilitates the maintenance of the transcriptionally repressive state of some genes, such as BCL6. It consists of the corepressor BCOR or BCORL1, a Polycomb group (PcG) and a SCF ubiquitin ligase subcomplexes.
In mammals, the core subunits of the complex include the PcG and PcG-associated proteins NSPC1, RING1, RNF2, and RYBP and the components of the SCF ubiquitin ligase, SKP1, and FBXL10.
A complex of several polypeptides that plays at least two important roles in protein synthesis: First, eIF3 binds to the 40S ribosome and facilitates loading of the Met-tRNA/eIF2.GTP ternary complex to form the 43S preinitiation complex. Subsequently, eIF3 apparently assists eIF4 in recruiting mRNAs to the 43S complex. The eIF3 complex contains five conserved core subunits, and may contain several additional proteins; the non-core subunits are thought to mediate association of the complex with specific sets of mRNAs.
A protein complex, formed of one or more myosin heavy chains plus associated light chains and other proteins, that functions as a molecular motor; uses the energy of ATP hydrolysis to move actin filaments or to move vesicles or other cargo on fixed actin filaments; has magnesium-ATPase activity and binds actin. Myosin classes are distinguished based on sequence features of the motor, or head, domain, but also have distinct tail regions that are believed to bind specific cargoes.
A trimeric protein complex required for the formation of a mature RNA-induced silencing complex (RISC). In humans the complex is composed of the endonuclease Dicer (DICER1), TRBP (TARBP2) and the Argonaute protein Ago2 (EIF2C2/AGO2). Within the complex, Dicer and TRBP are required to process precursor miRNAs (pre-miRNAs) to mature miRNAs and then load them onto Ago2. Ago2 bound to the mature miRNA constitutes the minimal RISC and may subsequently dissociate from Dicer and TRBP. This complex has endoribonuclease activity.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class Ib protein complex following intracellular transport via a pathway not requiring TAP (transporter associated with antigen processing). The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell. Class Ib here refers to non-classical class I molecules, such as those of the HLA-E gene family.
The formation of the non-fluorescent protein chromophore cross-link from the alpha-carboxyl carbon of residue n, a glutamic acid, to the alpha-amino nitrogen of residue n+2, a glycine, and a dehydration to form a double bond to the alpha-amino nitrogen of residue n+1. This cross-linking is coupled with a dehydrogenation of residue n+1 to form a double bond between the alpha and beta carbons. This modification is found in the GFP-like non-fluorescent red chromoprotein from the sea anemone Radianthus macrodactylus.
The formation of the fluorescent protein FP611 chromophore cross-link from the alpha-carboxyl carbon of residue n, a methionine, to the alpha-amino nitrogen of residue n+2, a glycine, and a dehydration to form a double bond to the alpha-amino nitrogen of residue n+1. This cross-linking is coupled with a dehydrogenation of residue n+1 to form a double bond between the alpha and beta carbons. This modification is found in the GFP-like fluorescent chromoprotein from the sea anemone Entacmaea quadricolor.
Any process that results in a change in state or activity of a cell (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a bacteriocin stimulus. A bacteriocin is a protein substance released by certain bacteria that kills but does not lyse closely related strains of bacteria. Specific bacteriocins attach to specific receptors on cell walls and induce specific metabolic block, e.g. cessation of nucleic acid or protein synthesis of oxidative phosphorylation.
A tight ring-shaped structure that forms in the division plane at the site of cytokinesis; composed of members of the conserved family of filament-forming proteins called septins as well as septin-associated proteins. This type of septin structure is observed at the bud neck of budding fungal cells, at the site of cell division in animal cells, at the junction between the mother cell and a pseudohyphal projection, and also within hyphae of filamentous fungi at sites where a septum will form.
A membrane-tethered, short cylindrical array of microtubules and associated proteins found at the base of a eukaryotic cilium (also called flagellum) that is similar in structure to a centriole and derives from it. The cilium basal body is the site of assembly and remodelling of the cilium and serves as a nucleation site for axoneme growth. As well as anchoring the cilium, it is thought to provide a selective gateway regulating the entry of ciliary proteins and vesicles by intraflagellar transport.
A protein complex that binds to heme and to pri-miRNAs, and is required for the formation of a pre-microRNA (pre-miRNA), the initial step of microRNA (miRNA) biogenesis. The complex is composed of the double-stranded-RNA-specific RNase Drosha (also called RNASEN) and the RNA-binding protein DGCR8 (heme-free or heme-bound forms). Within the complex, DGCR8 function as a molecular anchor necessary for the recognition of pri-miRNA at dsRNA-ssRNA junction and directs RNASEN/Drosha to cleave the 3' and 5' strands of a stem-loop to release hairpin-shaped pre-miRNAs.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class I protein complex following intracellular transport via a TAP-dependent ER pathway. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and becomes associated with the MHC class I molecule in the ER following TAP-dependent transport from the cytosol. Class I here refers to classical class I molecules.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class I protein complex following intracellular transport via a TAP-independent ER pathway. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and becomes associated with the MHC class I molecule in the ER following transport from the cytosol via a TAP-independent pathway. Class I here refers to classical class I molecules.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class Ib protein complex following intracellular transport via an ER pathway. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and becomes associated with the MHC class Ib molecule in the ER. Class Ib here refers to non-classical class I molecules, such as those of the HLA-E gene family.
A class of nuclear body, 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.
Any process in which a virus stops, prevents, or reduces the frequency, rate or extent of host PKR (protein kinase regulated by RNA) activity. Activation of PKR involves dsRNA binding followed by autophosphorylation. Phosphorylated PKR can then phosphorylate downstream targets such as the translation initiation factor eIF2 to inhibit protein synthesis. Viruses encode a number of mechanisms to inhibit the host antiviral response via PKR, including direct interaction with PKR, promoting degradation of PKR or altering the subcellular location of PKR.
Any process that results in a change in state or activity of a cell or an organism (in terms of movement, secretion, enzyme production, gene expression, etc.) as a result of a bacteriocin stimulus. A bacteriocin is a protein substance released by certain bacteria that kills but does not lyse closely related strains of bacteria. Specific bacteriocins attach to specific receptors on cell walls and induce specific metabolic block, e.g. cessation of nucleic acid or protein synthesis of oxidative phosphorylation.
An adrenergic receptor signaling pathway that contributes to an increase in frequency or rate of cardiac muscle contraction through phosphorylation and enhancement of the ryanodine receptor, a calcium-activated calcium-release channel found in the membrane of the sarcoplasmic reticulum. An adrenergic receptor-activated adenylate cyclase generates cAMP. cAMP then activates the cAMP-dependent protein kinase A (PKA), which phosphorylates the ryanodine receptor (RyR). PKA-phosphorylation of RyR enhances channel activity by sensitizing the channel to cytosolic calcium. Cytosolic calcium stimulates contractile proteins to promote muscle contraction.
Any dynein complex with a homodimeric dynein heavy chain core that catalyzes movement along a microtubule. Cytoplasmic dynein complexes participate in many cytoplasmic transport activities in eukaryotes, such as mRNA localization, intermediate filament transport, nuclear envelope breakdown, apoptosis, transport of centrosomal proteins, mitotic spindle assembly, virus transport, kinetochore functions, and movement of signaling and spindle checkpoint proteins. Some complexes participate in intraflagellar transport. Subunits associated with the dynein heavy chain mediate association between dynein heavy chain and cargoes, and may include light chains and light intermediate chains.
A complex for the transport of metabolites into the cell, consisting of 5 subunits: two ATP-binding subunits, two membrane spanning subunits, and one substrate-binding subunit. In organisms with two membranes, the substrate-binding protein moves freely in the periplasmic space and joins the other subunits only when bound with substrate. In organisms with only one membrane the substrate-binding protein is tethered to the cytoplasmic membrane and associated with the other subunits. Transport of the substrate across the membrane is driven by the hydrolysis of ATP.
The process in which an antigen-presenting cell expresses a peptide antigen of exogenous origin on its cell surface in association with an MHC class I protein complex following intracellular transport via a TAP (transporter associated with antigen processing) pathway. The peptide is typically a fragment of a larger exogenous protein which has been degraded within the cell and is dependent on TAP transport from the cytosol to ER for association with the MHC class I molecule. Class I here refers to classical class I molecules.
Any process that activates Factor XII (Hageman factor). Factor XII is a protein synthesized by the liver that circulates in an inactive form until it encounters collagen or basement membrane or activated platelets (as occurs at the site of endothelial injury). Factor XII then undergoes a conformational change (becoming factor XIIa), exposing an active serine center that can subsequently cleave protein substrates and activate a variety of mediator systems. Factor XII is a participant in the clotting cascade as well as the kinin cascade.
A protein complex capable of phosphatidylinositol 3-kinase activity and containing subunits of any phosphatidylinositol 3-kinase (PI3K) enzyme. These complexes are divided in three classes (called I, II and III) that differ for their presence across taxonomic groups and for the type of their constituents. Catalytic subunits of phosphatidylinositol 3-kinase enzymes are present in all 3 classes; regulatory subunits of phosphatidylinositol 3-kinase enzymes are present in classes I and III; adaptor proteins have been observed in class II complexes and may be present in other classes too.
Nuclear bodies frequently found near or associated with Cajal bodies (also called coiled bodies or CBs). Gemini of coiled bodies, or 'gems', are similar in size and shape to CBs, and often indistinguishable under the microscope. Unlike CBs, gems do not contain small nuclear ribonucleoproteins (snRNPs); they contain a protein called survivor of motor neurons (SMN) whose function relates to snRNP biogenesis. Gems are believed to assist CBs in snRNP biogenesis, and to play a role in the etiology of spinal muscular atrophy (SMA).
A filamentous structure formed of a two-stranded helical polymer of the protein actin and associated proteins. Actin filaments are a major component of the contractile apparatus of skeletal muscle and the microfilaments of the cytoskeleton of eukaryotic cells. The filaments, comprising polymerized globular actin molecules, appear as flexible structures with a diameter of 5-9 nm. They are organized into a variety of linear bundles, two-dimensional networks, and three dimensional gels. In the cytoskeleton they are most highly concentrated in the cortex of the cell just beneath the plasma membrane.
The process in which an antigen-presenting cell expresses a peptide antigen of endogenous origin on its cell surface in association with an MHC class Ib protein complex following intracellular transport via a TAP (transporter associated with antigen processing) pathway. The peptide is typically a fragment of a larger endogenous protein which has been degraded within the cell and is dependent on TAP transport from the cytosol to ER for association with the MHC class Ib molecule. Class Ib here refers to non-classical class I molecules, such as those of the HLA-E gene family.
Any intracellular signal transduction in which the signal is passed on within the cell by activation of a member of the NFAT protein family as a consequence of NFAT dephosphorylation by Ca(2+)-activated calcineurin. The cascade begins with calcium-dependent activation of the phosphatase calcineurin. Calcineurin dephosphorylates multiple phosphoserine residues on NFAT, resulting in the translocation of NFAT to the nucleus. The cascade ends with regulation of transcription by NFAT. The calcineurin-NFAT cascade lies downstream of many cell surface receptors, including G protein-coupled receptors (GPCRs) and receptor tyrosine kinases (RTKs) that signal to mobilize calcium ions (Ca2+).
Any of a series of ribonucleoprotein complexes that contain snRNA(s) and small nuclear ribonucleoproteins (snRNPs), and are formed sequentially during the spliceosomal splicing of one or more substrate RNAs, and which also contain the RNA substrate(s) from the initial target RNAs of splicing, the splicing intermediate RNA(s), to the final RNA products. During cis-splicing, the initial target RNA is a single, contiguous RNA transcript, whether mRNA, snoRNA, etc., and the released products are a spliced RNA and an excised intron, generally as a lariat structure. During trans-splicing, there are two initial substrate RNAs, the spliced leader RNA and a pre-mRNA.
