A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of structures formed of microtubules and associated proteins in phragmoplast, a plant cell specific structure that forms during late cytokinesis. Phragmoplast serves as a scaffold for cell plate assembly and subsequent formation of a new cell wall separating the two daughter cells.
A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of the plastoglobule. Plastoglobule is a lipoprotein particle present in chloroplasts. They are rich in non-polar lipids (triglycerides, esters) as well as in prenylquinones, plastoquinone and tocopherols. Plastoglobules are often associated with thylakoid membranes, suggesting an exchange of lipids with thylakoids.
The rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal, most prokaryotic cells and some protozoan parasites, maintaining their shape and protecting them from osmotic lysis. In plants it is made of cellulose and, often, lignin; in fungi it is composed largely of polysaccharides; in bacteria it is composed of peptidoglycan; in protozoan parasites such as Giardia species, it's made of carbohydrates and proteins.
Primary active transporter of a solute across a membrane, via the reaction: ATP + H2O = ADP + phosphate, to directly drive the transport of a substance across a membrane. The transport protein may be transiently phosphorylated (P-type transporters), or not (ABC-type transporters and other families of transporters). Primary active transport occurs up the solute's concentration gradient and is driven by a primary energy source.
Any of the granules, approximately 32 nm x 48 nm and consisting of highly aggregated phycobiliproteins, that are attached in arrays to the external face of a thylakoid membrane in algae of the phyla Cyanophyta and Rhodophyta, where they function as light-harvesting devices in photosynthesis. Excitation energy in the phycobilisome flows in the sequence: phycoerythrin, phycocyanin, allophycocyanin before passing to the antenna chlorophyll of photosystem II.
An extracellular matrix consisting mainly of proteins (especially collagen) and glycosaminoglycans (mostly as proteoglycans) that provides not only essential physical scaffolding for the cellular constituents but can also initiate crucial biochemical and biomechanical cues required for tissue morphogenesis, differentiation and homeostasis. The components are secreted by cells in the vicinity and form a sheet underlying or overlying cells such as endothelial and epithelial cells.
A class III phosphatidylinositol 3-kinase complex that contains a phosphatidylinositol-3-phosphate 5-kinase subunit (Fab1p in yeast; PIKfyve in mammals), a kinase activator, and a phosphatase, and may also contain additional proteins; it is involved in regulating the synthesis and turnover of phosphatidylinositol 3,5-bisphosphate. In mammals the complex is composed of PIKFYVE, FIG4 and VAC14. In yeast it is composed of Atg18p, Fig4p, Fab1p, Vac14p and Vac7p.
The cell cycle process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules. This occurs during meiosis.
A complex composed of two gamma-tubulin molecules and conserved non-tubulin proteins located in the spindle pole body and isolated by fractionation from cells. The complex, approximately 6S-9S, is analogous to the small complex in animal cells but contains fewer subunits, and is not thought to multimerize into larger functional units, like complexes in those organisms. An example of this structure is found in Saccharomyces cerevisiae.
The chemical reactions and pathways involving a cofactor, a substance that is required for the activity of an enzyme or other protein. Cofactors may be inorganic, such as the metal atoms zinc, iron, and copper in certain forms, or organic, in which case they are referred to as coenzymes. Cofactors may either be bound tightly to active sites or bind loosely with the substrate.
Any process that modulates the frequency, rate or extent of cholesterol esterification. Cholesterol esterification is the lipid modification process in which a sterol ester is formed by the combination of a carboxylic acid (often a fatty acid) and cholesterol. In the blood this process is associated with the conversion of free cholesterol into cholesteryl ester, which is then sequestered into the core of a lipoprotein particle.
Any process that increases the frequency, rate or extent of cholesterol esterification. Cholesterol esterification is the lipid modification process in which a sterol ester is formed by the combination of a carboxylic acid (often a fatty acid) and cholesterol. In the blood this process is associated with the conversion of free cholesterol into cholesteryl ester, which is then sequestered into the core of a lipoprotein particle.
A heterodimeric transcription factor complex composed of proteins from the c-Fos, c-Jun, activating transcription factor (ATF) or JDP families. The subunits contain a basic leucine zipper (bZIP) domain that is essential for dimerization and DNA binding. Jun-Fos heterodimers bind preferentially to a heptamer consensus sequence (TPA responsive element (TRE)), whereas Jun-ATF dimers bind the cyclic AMP responsive element (CRE) to regulate transcription of target genes.
A protein complex that contains a disulfide-linked heterodimer of T cell receptor (TCR) chains, which are members of the immunoglobulin superfamily, and mediates antigen recognition, ultimately resulting in T cell activation. The TCR heterodimer is associated with the CD3 complex, which consists of the nonpolymorphic polypeptides gamma, delta, epsilon, zeta, and, in some cases, eta (an RNA splice variant of zeta) or Fc epsilon chains.
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 glucocorticoid stimulus. Glucocorticoids are hormonal C21 corticosteroids synthesized from cholesterol with the ability to bind with the cortisol receptor and trigger similar effects. Glucocorticoids act primarily on carbohydrate and protein metabolism, and have anti-inflammatory effects.
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 glucocorticoid stimulus. Glucocorticoids are hormonal C21 corticosteroids synthesized from cholesterol with the ability to bind with the cortisol receptor and trigger similar effects. Glucocorticoids act primarily on carbohydrate and protein metabolism, and have anti-inflammatory effects.
The series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes that modulates the rate or frequency of pancreatic B cell proliferation. Pancreatic B cell are cells of the pancreas that secrete insulin.
A part of the endomembrane system in the form of an invagination of a membrane upon which a clathrin coat forms, and that can be converted by vesicle budding into a clathrin-coated vesicle. Coated pits form on the plasma membrane, where they are involved in receptor-mediated selective transport of many proteins and other macromolecules across the cell membrane, in the trans-Golgi network, and on some endosomes.
A membrane raft that forms small pit, depression, or invagination that communicates with the outside of a cell and extends inward, indenting the cytoplasm and the cell membrane. Examples include flask-shaped invaginations of the plasma membrane in adipocytes associated with caveolin proteins, and minute pits or incuppings of the cell membrane formed during pinocytosis. Caveolae may be pinched off to form free vesicles within the cytoplasm.
The specialized envelope lying outside the cell membrane of a cyst. A cyst is a resting or dormant stage of a microorganism, usually a bacterium or a protist or rarely an invertebrate animal, that helps the organism to survive in unfavorable environmental conditions. In protists such as protozoan parasites alternating cystic- and non-cystic stages, the cyst wall is usually composed of carbohydrates and proteins.
A ubiquitin ligase complex consisting of MUB1, RAD6 and UBR2 components. It ubiquitinates, and targets for destruction, the RPN4 transcription factor, which upregulates the proteasome genes. The binding of MUB1 may position the RPN4 ubiquitylation site proximal to the Ubiquitin-RAD6 thioester and allow the transfer of Ubiquitin from RAD6 to RPN4. One of its components, MUB1, is a short-lived protein ubiquitinated by the UBR2-RAD6 ubiquitin conjugating enzyme.
Protein complex found in Drosophila consisting of the gene products of cuff, del and rhi. It regulates the licensing of transcription of dual-strand PIWI interacting RNA (piRNA) source loci by binding to dual-strand-cluster chromatin, probably via the H3K9me3-binding activity of Rhi. Rhi binding brings the putative termination cofactor Cuff in close proximity to the nascent piRNA precursor transcript which it appears to protect from degradation.
Protein complex required for the asymmetric division of neuroblasts in Drosophila. Coordinates asymmetric localization of cell fate determinants with orientation of the mitotic spindle resulting in different daughter cells upon division. Localizes at the apical cortex of the neuroblast: Raps maintains, but does not initiate, Insc apically, while Insc segregates Raps asymmetrically. Complex appears to be conserved in mammals (composed of INSC and GPSM1 or GPSM2).
A protein complex consisting of one subunit known as Dom34 or Pelota that has similarity to translation termination factor eRF1, and another subunit, Hbs1, that is a GTPase with similarity to translation termination factor eRF3. The Dom34-Hbs1 complex has a role in cotranslational mRNA quality control by promoting ribosomal subunit dissociation and peptidyl-tRNA release when translation is stalled, facilitating no-go decay and nonstop decay.
A protein complex composed of S100A8 and S100A9 and capable of limiting Mn(2+) and Zn(2+) availability at sites of infection. Also binds Ca(2+). Expressed and released by neutrophils and epithelial cells, it exhibits broad-spectrum antimicrobial activity attributed to its metal-binding properties. Endogenous ligand of toll-like receptor 4 (TLR4) and of the receptor for advanced glycation end products (RAGE) initiating signal transduction through NF-kappa-B pathways.
A process that is carried out at the cellular level which results in the assembly, arrangement of constituent parts, or disassembly of a platelet dense granule. A platelet dense granule is an electron-dense granule occurring in blood platelets that stores and secretes adenosine nucleotides and serotonin. They contain a highly condensed core consisting of serotonin, histamine, calcium, magnesium, ATP, ADP, pyrophosphate and membrane lysosomal proteins.
A complex composed of two gamma-tubulin molecules and conserved non-tubulin proteins located in the mitotic spindle pole body and isolated by fractionation from cells. The complex, approximately 6S-9S, is analogous to the small complex in animal cells but contains fewer subunits, and is not thought to multimerize into larger functional units, like complexes in those organisms. An example of this structure is found in Saccharomyces cerevisiae.
A type of programmed cell death that occurs in the epidermis, morphologically and biochemically distinct from apoptosis. It leads to the formation of corneocytes, i.e. dead keratinocytes containing an amalgam of specific proteins (e.g., keratin, loricrin, SPR and involucrin) and lipids (e.g., fatty acids and ceramides), which are necessary for the function of the cornified skin layer (mechanical resistance, elasticity, water repellence and structural stability).
The process in which a relatively unspecialized cell acquires specialized features of a lens fiber cell, any of the elongated, tightly packed cells that make up the bulk of the mature lens in the camera-type eye. The cytoplasm of a lens fiber cell is devoid of most intracellular organelles including the cell nucleus, and contains primarily crystallins, a group of water-soluble proteins expressed in vary large quantities.
A protein complex composed of two identical immunoglobulin heavy chains of the IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and sometimes complexed with J chain or J chain and secretory component. An IgA 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.
A protein complex composed of two identical immunoglobulin heavy chains of the IgM isotype and two identical immunoglobulin light chains, held together by disulfide bonds, and in its circulating form complexed with J chain in polymeric forms. An IgM 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.
The invasion by a symbiont of a cell of a host organism, forming a vacuole in which the symbiont resides. The vacuole membrane is formed from lipids and proteins derived from both host and symbiont. Begins when the symbiont attaches on to the host cell membrane which invaginates and deepens as the symbiont enters, and ends when the host cell membrane closes behind the newly-formed vacuole.
An angiotensin-mediated signaling pathway that contributes to a circulatory system process carried out by the heart, where the activated receptor transmits the signal via Gq-mediated activation of phospholipase C (PLC). PLC hydrolyses phosphatidylinositol 4,5-bisphosphate (PIP2) into the second messengers inositol-1,4,5,-triphosphate (IP3) and diacylglycerol (DAG). DAG activates protein kinase C (PKC), whilst IP3 binds intracellular receptors to induce the release of Ca2+ from intracellular stores.
A nuclear DNA-directed RNA polymerase complex containing an RNA polymerase II core enzyme as well as additional proteins and transcription factor complexes, that are capable of promoter recognition and transcription initiation from an RNA polymerase II promoter in vivo. These additional components may include general transcription factor complexes TFIIA, TFIID, TFIIE, TFIIF, or TFIIH, as well as Mediator, SWI/SNF, GCN5, or SRBs and confer the ability to recognize promoters.
An occluding cell-cell junction that is composed of a branching network of sealing strands that completely encircles the apical end of each cell in an epithelial sheet; the outer leaflets of the two interacting plasma membranes are seen to be tightly apposed where sealing strands are present. Each sealing strand is composed of a long row of transmembrane adhesion proteins embedded in each of the two interacting plasma membranes.
A protein complex that possesses histone acetyltransferase activity and links histone acetylation to the assembly of transcriptionally silent chromatin. In vitro, the complex acetylates lysine 16 of histone H4 and lysine 14 of histone H3, although the latter may not be relevant in vivo. The complex contains a catalytic subunit and at least two other subunits; in Saccharomyces, the catalytic subunit is Sas2p and additional subunits are Sas4p and Sas5p.
The process where the "Cap structure" (composed of a 7- methylguanosine (m7G) group and associated cap-binding proteins) located at the 5' end of an mRNA molecule, which serves as a "molecular tag" that marks the spot where the 40S ribosomal subunit is recruited and will then scan in a 5' to 3' direction until an AUG codon is encountered in an appropriate sequence context to initiate mRNA translation.
Any process that increases the activity of a transcription factor that activates transcription of Hedgehog-target genes in response to Smoothened signaling. In Drosophila, Cubitus interruptus (Ci) is the only identified transcription factor so far in the Hedgehog signaling pathway. In vertebrates, members of the Gli protein family are activated in this way. Activation of the Gli/Ci transcription factor is distinct from its stabilization, when proteolytic cleavage is inhibited.
The chemical reactions and pathways involving heparin, any member of a group of glycosaminoglycans found mainly as an intracellular component of mast cells. They are similar to heparan sulfates but are of somewhat higher average Mr (6000-20000) and contain fewer N-acetyl groups and more N-sulfate and O-sulfate groups; they may be attached in the same manner to protein, forming proteoglycans. They consist predominantly of alternating alpha-(1->4)-linked D-galactose and N-acetyl-D-glucosamine-6-sulfate residues.
A pair of rings that flank the site of cell division, formed by splitting of the septin ring (or collar) prior to cytokinesis; this double ring structure is thought to trap proteins needed for cytokinesis or the formation of the new membrane or cell wall between the two septin rings. Split septin rings are known to occur in budding yeast cells and probably occur in other cell types as well.
A complex composed of two proteins, prohibitin 1 and prohibitin 2 (PHB1/PHB-1 and PHB2/PHB-2) that is highly conserved amongst eukaryotes and associated with the inner mitochondrial membrane. The mitochondrial prohibitin complex is a macromolecular supercomplex composed of repeating heterodimeric subunits of PHB1 and PHB2. The mitochondrial prohibitin complex plays a role in a number of biological processes, including mitochondrial biogenesis and function, development, replicative senescence, and cell death.
A cell tip which has existed for at least one complete cell cycle, and at which polarized growth occurs, which is part of a cell that has activated bipolar cell growth (i.e. in which new end take-off, NETO, has taken place). For example, in fission yeast the cell end that existed prior to cell division grows immediately after division, and contains a distinctive complement of proteins including actin cytoskeletal structures.
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.
A muscle cell-specific SWI/SNF-type complex that contains eight to fourteen proteins, including both conserved (core) and nonconserved components; contains the ATPase product of either the SMARCA4/BAF190A/BRG1 gene, the mammalian ortholog of the yeast SNF2 gene, or the SMARCA2/BAF190B/BRM gene, the mammalian ortholog of the Drosophila brm (brahma) gene, or an ortholog of either of these genes, and the muscle-specific product of the DPF3/BAF45C gene or an ortholog thereof.
A protein complex composed of a S100A9 dimer and capable of binding to toll-like receptor 4 (TLR4) and the receptor for advanced glycation end products (RAGE) initiating signal transduction through NF-kappa-B pathways. Transports arachidonic acid between the cytosol and the NADPH oxidase complex at the plasma membrane in neutrophils as part of an inflammatory signal cascade leading to an oxidative burst. Complexes with microtubules to increase cell motility.
The chemical reactions and pathways involving fractalkine, a chemokine involved in the control of the key regulatory mechanisms of cell trafficking at sites of inflammation. It exists as a secreted protein and in a membrane-bound form, and exhibits a novel C-X-X-X-C cysteine signature motif. The counterpart of human fractalkine is murine neurotactin; fractalkine is also referred to as CX3C membrane-anchored chemokine or ABCD-3 and has been renamed CX3CL1.
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 cortisol stimulus. Cortisol is the major natural glucocorticoid synthesized in the zona fasciculata of the adrenal cortex; it affects the metabolism of glucose, protein, and fats and has appreciable mineralocorticoid activity. It also regulates the immune system and affects many other functions.
Any process that modulates the rate, frequency, or extent of the Wnt signaling pathway through beta-catenin involved in neural crest cell differentiation. The Wnt signaling pathway is the series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes.
Any process that decreases the rate, frequency, or extent of the Wnt signaling pathway through beta-catenin involved in neural crest cell differentiation. The Wnt signaling pathway is the series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes.
Any process that increases the rate, frequency, or extent of the Wnt signaling pathway through beta-catenin involved in neural crest cell differentiation. The Wnt signaling pathway is the series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes.
Any process that modulates the rate, frequency or extent of canonical Wnt signaling pathway that regulates heart induction. Canonical Wnt signaling pathway involved in heart induction is the series of molecular signals initiated by binding of Wnt protein to a frizzled family receptor on the surface of the target cell, followed by relaying of the signal via beta-catenin, and ending with a change in transcription of target genes.
Any process that decreases the rate, frequency or extent of canonical Wnt signaling pathway that positively regulates heart induction. Canonical Wnt signaling pathway involved in heart induction is the series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes.
A protein or a member of a complex that interacts specifically and non-covalently with a DNA-bound DNA-binding transcription factor to either activate or repress the transcription of specific genes. Coregulators often act by altering chromatin structure and modifications. For example, one class of transcription coregulators modifies chromatin structure through covalent modification of histones. A second ATP-dependent class modifies the conformation of chromatin. A third class modulates interactions of DNA-binding transcription factor with other transcription coregulators.
The acquisition of peroxisomes by daughter cells from the mother cell after replication. In Saccharomyces cerevisiae, the number of peroxisomes cells is fairly constant; a subset of the organelles are targeted and segregated to the bud in a highly ordered, vectorial process. Efficient segregation of peroxisomes from mother to bud is dependent on the actin cytoskeleton, and active movement of peroxisomes along actin filaments is driven by the class V myosin motor protein, Myo2p.
Any of several heterotetrameric complexes that link clathrin (or another coat-forming molecule, as hypothesized for AP-3 and AP-4) to a membrane surface; they are found on coated pits and coated vesicles, and mediate sorting of cargo proteins into vesicles. Each AP complex contains two large (a beta and one of either an alpha, gamma, delta, or epsilon) subunits (110-130 kDa), a medium (mu) subunit (approximately 50 kDa), and a small (sigma) subunit (15-20 kDa).
A phosphatidylinositol 3-kinase complex that contains a catalytic and a regulatory subunit of a phosphatidylinositol 3-kinase (PI3K) enzyme, plus one or more adaptor proteins. Class I PI3Ks phosphorylate phosphatidylinositol [PI], phosphatidylinositol-4-phosphate [PI(4)P] and phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], and are divided into subclasses A and B according to the type of adaptor subunit with which they associate. The class I PI3K subfamily of genes comprises members in vertebrates, worm and fly, but none in yeast.
A protein complex that functions as an endonuclease to cleave DNA at or near a specific recognition site, when that site is unmethylated. These complexes may be dimers or tetramers; it is also possible for the endonuclease to be in a complex with the corresponding methyltransferase that methylates the recognition site. DNA restriction systems such as this are used by bacteria to defend against phage and other foreign DNA that may enter a cell.
The commitment of cells to specific cell fates and their capacity to differentiate into particular kinds of cells within a field of cells that will exhibit a certain pattern of differentiation. Positional information is established through protein signals that emanate from a localized source within a developmental field resulting in specification of a cell type. Those signals are then interpreted in a cell-autonomous manner resulting in the determination of the cell type.
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.
A tubular structure with flared ends, shaped like an hourglass and composed of highly ordered arrays of septin filaments, that forms at the bud neck of a dividing cell. In S. cerevisiae, this structure is located at the bud neck throughout most of the cell cycle and the septins are fixed within the structure, not exchanging with soluble septins. This septin structure acts as a scaffold for other proteins that function at the bud neck.
The process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA at the mating-type locus. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules. This process occurs as part of gene conversion at the mating-type locus.
Any process that increases the rate, frequency or extent of strand invasion. Strand invasion is the process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules.
The circularization of a viral genome following infection of a host cell. This is common amongst bacterial viruses to protect the viral genome ends from nucleases, to convert the linear genome to an integrative precursor or to give rise to the replicative form of the genome. It can be mediated by covalent closure of the DNA sticky ends, recombinaison between redundant terminal sequences or via the binding of a protein at the viral DNA extremities
The chemical reactions and pathways resulting in the formation of fractalkine, a chemokine involved in the control of the key regulatory mechanisms of cell trafficking at sites of inflammation. It exists as a secreted protein and in a membrane-bound form, and exhibits a novel C-X-X-X-C cysteine signature motif. The counterpart of human fractalkine is murine neurotactin; fractalkine is also referred to as CX3C membrane-anchored chemokine or ABCD-3 and has been renamed CX3CL1.
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 cortisol stimulus. Cortisol is the major natural glucocorticoid synthesized in the zona fasciculata of the adrenal cortex; it affects the metabolism of glucose, protein, and fats and has appreciable mineralocorticoid activity. It also regulates the immune system and affects many other functions.
Any process that modulates the rate, frequency or extent of strand invasion. Strand invasion is the process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules.
Any process that decreases the rate, frequency or extent of strand invasion. Strand invasion is the process in which the nucleoprotein complex (composed of the broken single-strand DNA and the recombinase) searches and identifies a region of homology in intact duplex DNA. The broken single-strand DNA displaces the like strand and forms Watson-Crick base pairs with its complement, forming a duplex in which each strand is from one of the two recombining DNA molecules.
A protein complex essential for autophagy during nutrient deprivation, a catabolic process that sequesters undesired cellular material into autophagosomes for delivery to lysosomes for degradation. Contributes to nutrition homeostasis and damage control in eukaryotic cells. Functions at a late step of autophagosome formation for efficient completion of sequestration, probably through facilitating recruitment of ATG8-phosphatidylethanolamine (PE) to the preautophagosomal structure (PAS) and/or its protection from deconjugation by ATG4. Composed of ATG2 and ATG18 in Saccharomyces cerevisiae.
A spliceosomal complex that is formed by association of the 5' splice site and the branch point sequence with specific snRNPs. The prespliceosome includes many proteins in addition to those found in the bound snRNPs. Commitment to a given pair of 5' and 3' splice sites occurs at the time of prespliceosome formation. Prespliceosome complexes are not active for splicing, but are instead an early step in the assembly of a spliceosomal complex.
The controlled release of a nectar by a cell or a tissue. Nectar is a fluid secreted by many angiosperms to promote pollination by providing a reward to pollinators. Nectar may also deter certain organisms from visiting or play other biological roles. Nectar is a complex solution that may include the following types of compounds: sugars, amino acids, organic acids, alkaloids, flavonoids, glycosides, vitamins, phenolics, metal ions, oils, free fatty acids, and proteins.
An extracellular membrane-bounded vesicle that contains prominin proteins (in mouse Prom1/CD33 or Prom2) and are found in body fluids including ventricular fluid, saliva, urine and seminal fluid. In the ventricular fluid of the developing mouse brain two major classes of these particles have been observed (P2 particles of 500-1000 nm and P4 particles of 50-80 nm) which likely originate from microvilli, primary cilia and/or the midbody of neuroepithelial cells. The physiological role is not known.
A multiprotein complex having distributive polyadenylation activity of a variety of RNA substrates including hypomodified and incorrectly folded tRNAs, pre-snRNAs, pre-snoRNAs, incorrectly spliced or processed pre-mRNAs, cryptic unstable transcripts (CUTs), pre-rRNAs and rRNA fragments released as part of rRNA processing. In S. cerevisiae, the complex consists of either Pap2 (also known as Trf4) or Trf5, Air1 or Air2, and Mtr4, and is involved in RNA 3'-end processing and in RNA surveillance and quality control.
The cellular metabolic process in which a cell duplicates one or more molecules of DNA. DNA replication begins when specific sequences, known as origins of replication, are recognized and bound by initiation proteins, and ends when the original DNA molecule has been completely duplicated and the copies topologically separated. The unit of replication usually corresponds to the genome of the cell, an organelle, or a virus. The template for replication can either be an existing DNA molecule or RNA.
A cellular process that results in the biosynthesis of constituent macromolecules, assembly, and arrangement of constituent parts of a cell wall. Includes biosynthesis of constituent macromolecules, such as proteins and polysaccharides, and those macromolecular modifications that are involved in synthesis or assembly of the cellular component. A cell wall is the rigid or semi-rigid envelope lying outside the cell membrane of plant, fungal and most prokaryotic cells, maintaining their shape and protecting them from osmotic lysis.
The formation of a tri-snRNP complex containing U4 and U6 (or U4atac and U6atac) snRNAs and U5 snRNAs and associated proteins. This includes reannealing of U4 and U6 (or U4atac and U6atac) snRNAs released from previous rounds of splicing to reform the U4/U6 snRNP (or U4atac/U6atac snRNP) as well as the subsequent association of the U5 snRNP with the U4/U6 snRNP (or U4atac/U6atac snRNP) to form a tri-snRNP that is ready to reassemble into another spliceosome complex.
The chemical reactions and pathways involving snoRNA, small nucleolar RNA, any of a class of small RNAs that are associated with the eukaryotic nucleus as components of small nucleolar ribonucleoproteins. They participate in the processing or modifications of many RNAs, mostly ribosomal RNAs (rRNAs) though snoRNAs are also known to target other classes of RNA, including spliceosomal RNAs, tRNAs, and mRNAs via a stretch of sequence that is complementary to a sequence in the targeted RNA.
A series of molecular signals initiated by the binding of a member of the BMP (bone morphogenetic protein) family to a receptor on the surface of a target cell, which contributes to the modulation of the frequency, rate or extent of cardioblast proliferation in the secondary heart field. A cardioblast is a cardiac precursor cell. It is a cell that has been committed to a cardiac fate, but will undergo more cell division rather than terminally differentiating.
Any process in which the symbiont modulates the frequency, rate or extent of receptor-mediated signal transduction in the host organism. The receptor is defined as a protein on the cell membrane or within the cytoplasm or cell nucleus that binds to a specific molecule (a ligand) such as a neurotransmitter or a hormone or other substance, and initiates the cellular response to the ligand. The host is defined as the larger of the organisms involved in a symbiotic interaction.
A viral process by which enveloped viruses acquire a host-derived membrane enriched in viral proteins to form their external envelope. The process starts when nucleocapsids, assembled or in the process of being built, induce formation of a membrane curvature in the host plasma or organelle membrane and wrap up in the forming bud. The process ends when the bud is eventually pinched off by membrane scission to release the enveloped particle into the lumenal or extracellular space.
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 corticosteroid hormone stimulus. A corticosteroid is a steroid hormone that is produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior. They include glucocorticoids and mineralocorticoids.
A heterotrimeric protein complex with iron-sulfur and molybdenum cofactors that functions as a terminal reductase in electron transport pathways that operate during anaerobic nitrate respiration. In E. coli electrons are passed from the FdnGHI complex to the NarGHI complex via menoquinone and menaquinol. Within NarGHI, electrons are passed from the two heme molecules in the NarI subunit down a Fe-S cluster chain in the NarH and NarG subunits to the Molybdenum cofactor, Mo-bisMGD, in the NarG subunit.
A brain-specific SWI/SNF-type complex that contains eight or nine proteins, including both conserved (core) and nonconserved components; contains the ATPase product of either the SMARCA4/BAF190A/BRG1 gene, the mammalian ortholog of the yeast SNF2 gene, or the SMARCA2/BAF190B/BRM gene, the mammalian ortholog of the Drosophila brm (brahma) gene, or an ortholog of either of these genes. Compared to the neuron-specific nBAF complex (GO:0071565) it does not contain DPF1, DPF3 or SMARCC1 or their orthologs. May contain PB1/BAF180.
A series of molecular signals initiated by an extracellular amylin, or another ligand, combining with an amylin receptor 3 (AMY3), a G protein-coupled receptor complex, on the surface of the target cell. The AMY3 signaling pathway can also be initiated by the amyloid-beta complex. AMY3 signaling results in increased import of calcium ions into the cytosol across plasma membrane, increased phosphorylation of ERK1/2, Act, and a PKA regulatory subunit II, as well as increased expression of cFos.
A protein complex that consists of three components, NLRP3 (NALP3), PYCARD and caspase-1. It is activated upon exposure to whole pathogens, as well as a number of structurally diverse pathogen- and danger-associated molecular patterns (PAMPs and DAMPs) and environmental irritants. Whole pathogens demonstrated to activate the NLRP3 inflammasome complex include the fungi Candida albicans and Saccharomyces cerevisiae, bacteria that produce pore-forming toxins, including Listeria monocytogenes and Staphylococcus aureus, and viruses such as Sendai virus, adenovirus, and influenza virus.
Interacting selectively and non-covalently with one or more specific sites on a receptor molecule, a macromolecule that undergoes combination with a hormone, neurotransmitter, drug or intracellular messenger to initiate a change in cell function.
Any process that modulates the frequency, rate or extent of symbiont MAP kinase-mediated signal transduction during appressorium formation on or near its host organism. The host is defined as the larger of the organisms involved in a symbiotic interaction.
A protein complex that forms part of a proton-transporting V-type ATPase and catalyzes ATP hydrolysis. The V1 complex consists of: (1) a globular headpiece with three alternating copies of subunits A and B that form a ring, (2) a central rotational stalk composed of single copies of subunits D and F, and (3) a peripheral stalk made of subunits C, E, G and H. Subunits A and B mediate the hydrolysis of ATP at three reaction sites associated with subunit A.
The series of molecular signals initiated by binding of a Wnt protein to a frizzled family receptor on the surface of the target cell, followed by propagation of the signal via beta-catenin, and ending with a change in transcription of target genes. In this pathway, the activated receptor signals via downstream effectors that result in the inhibition of beta-catenin phosphorylation, thereby preventing degradation of beta-catenin. Stabilized beta-catenin can then accumulate and travel to the nucleus to trigger changes in transcription of target genes.
A large, club-shaped secretory organelle that forms part of the apical complex of an apicomplexan parasite, and consists of a bulbous body and a narrow electron-dense neck that extends through the conoid at the apical tip of the parasite. The rhoptry necks serve as ducts through which the contents of the rhoptries are secreted after attachment to the host has been completed and at the commencement of invasion. Rhoptry proteins function in the biogenesis and host organellar association of the parasitophorous vacuole.
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 corticosteroid hormone stimulus. A corticosteroid is a steroid hormone that is produced in the adrenal cortex. Corticosteroids are involved in a wide range of physiologic systems such as stress response, immune response and regulation of inflammation, carbohydrate metabolism, protein catabolism, blood electrolyte levels, and behavior. They include glucocorticoids and mineralocorticoids.
The physiological and developmental changes that occur in a conidium or asexual spore following release from dormancy up to the earliest signs of development such as swelling of conidia, adhesion and nuclear decondensation followed by hyphal growth several hours later. In many genera of plant pathogenic fungi (e.g. Magnaporthe, Colletotrichum, Ustilago), swelling of the hyphal tips to form appressorium, metabolic activities including respiration, RNA and protein synthesis and trehalose breakdown and changes in cell wall composition can be detected in conidium germination.
A protein complex consisting of two chains of platelet-derived growth factor (PDGF) subunits. PDGF dimers bind to PDGF receptors in the plasma membrane and induce receptor dimerisation and activation. PDGFs are involved in a wide variety of signalling processes. PDGFs are found in all vertebrates where at least 2 different chains (A and B) exist. In human (and other mammals), four types of PDGF chains (A, B, C, and D) are known which form five different dimers (AA, AB, BB, CC and DD).
A protein complex composed of two monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through a disulfide binded monomer of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.
A complex composed of TATA binding protein (TBP) and TBP associated factors (TAFs); the total mass is typically about 800 kDa. Most of the TAFs are conserved across species. In TATA-containing promoters for RNA polymerase II (Pol II), TFIID is believed to recognize at least two distinct elements, the TATA element and a downstream promoter element. TFIID is also involved in recognition of TATA-less Pol II promoters. Binding of TFIID to DNA is necessary but not sufficient for transcription initiation from most RNA polymerase II promoters.
The splicing of Group II introns. This occurs by a ribozymic mechanism where the intron sequence forms a distinct 3D structure, characteristic of Group II introns and containing splice site consensus sequences, that is involved in catalyzing the splicing reactions, though protein factors are also required in vivo. Splicing occurs by a series of two transesterification reactions (mechanistically similar to those for splicing of nuclear mRNAs) initiated by a bulged adenosine residue within the intron sequence as the initiating nucleophile. The intron is excised as a lariat.
A tetrameric protein complex consisting of two platelet-derived growth factor (PDGF) receptor subunits and two PDGF ligand subunits. Binding of the PDGF ligand dimer to the PDGF receptor in the plasma membrane induces receptor dimerisation and activation. PDGFs are involved in a wide variety of signalling processes and are found in all vertebrates. At least two different receptor chains (A and B) and four types of ligand chains (A, B, C, and D) are known forming a wide variety of combinations of receptor-ligand complexes.
A protein complex composed of two, three, or four monomeric IgA immunoglobulin complexes linked through both direct disulfide bonds and through disulfide binded monomers of J chain acting as a bridge. Each IgA monomer consists of two identical immunoglobulin heavy chains of an IgA isotype and two identical immunoglobulin light chains, held together by disulfide bonds. Dimeric IgA is sometimes complexed additionally with secretory component, and present in the extracellular space, in mucosal areas or other tissues, or circulating in the blood or lymph.
An adrenergic receptor signaling pathway that contributes to an increase in frequency or rate of heart contraction. Binding of adrenalin or noradrenalin to a beta-adrenergic receptor on the surface of the signal-receiving cell results in the activation of an intracellular Gs protein. Gs activates adenylate cyclase to increase intracellular cyclic-AMP (cAMP) levels. cAMP binds directly to F-channels to allow an inward flow of sodium (known as funny current, or If current). The funny current is responsible for membrane depolarization and an increase in heart rate.
A protein or a member of a complex that interacts specifically and non-covalently with a DNA-bound DNA-binding transcription factor to activate the transcription of specific genes. Coactivators often act by altering chromatin structure and modifications. For example, one class of transcription coregulators modifies chromatin structure through covalent modification of histones. A second ATP-dependent class modifies the conformation of chromatin. Another type of coregulator activity is the bridging of a DNA-binding transcription factor to the basal transcription machinery. The Mediator complex, which bridges transcription factors and RNA polymerase, is also a transcription coactivator.
A protein complex composed of three identical PCNA monomers, each comprising two similar domains, which are joined in a head-to-tail arrangement to form a homotrimer. Forms a ring-like structure in solution, with a central hole sufficiently large to accommodate the double helix of DNA. Originally characterized as a DNA sliding clamp for replicative DNA polymerases and as an essential component of the replisome, and has also been shown to be involved in other processes including Okazaki fragment processing, DNA repair, translesion DNA synthesis, DNA methylation, chromatin remodeling and cell cycle regulation.
