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  • domain-containi
  • Following the discovery of StAR, 15 START-domain-containing proteins (termed STARD1 through STARD15) were subsequently identified in vertebrates as well as other that are related. (wikipedia.org)
  • START domain-containing proteins in the human are divided into five subfamilies. (wikipedia.org)
  • mRNA
  • Through this pathway it is possible to facilitate the movement of essential molecules such as membrane‐bounded vesicles and organelles, protein rafts, mRNA and chromosomes. (wikipedia.org)
  • genes
  • This protein likely functions as a trigger for apoptosis through upregulation of genes necessary for cell death, such as Bim and PUMA, or downregulation of anti-apoptotic proteins such as FLIP. (wikipedia.org)
  • Upon sterol depletion, LXRs are inactive and SREBPs are cleaved, after which they bind promoter SREs and activate genes involved in cholesterol biosynthesis and uptake. (wikipedia.org)
  • cholesterol
  • The conversion from cholesterol to cholic and chenodeoxycholic acids involves four steps: 1) the initiation of synthesis by 7alpha-hydroxylation of sterol precursors, 2) further modifications to the ring structures, 3) side-chain oxidation and shortening (cleavage) by three carbons, and 4) conjugation of the bile acid with taurine or glycine. (genome.jp)
  • Most importantly, the interior of the protein encompasses a 26 × 12 × 11-Angstrom hydrophobic tunnel that is apparently large enough to bind a single cholesterol molecule. (wikipedia.org)
  • While StAR may bind cholesterol itself, the exorbitant number of cholesterol molecules that the protein transfers would indicate that it would have to act as a cholesterol channel instead of a shuttle. (wikipedia.org)
  • STARD5 binds both cholesterol and 25-hydroxycholesterol and appears to function to redistribute cholesterol to the endoplasmic reticulum with which the protein associates and/or the plasma membrane. (wikipedia.org)
  • Cholesterol homeostasis is regulated, at least in part, by sterol regulatory element (SRE)-binding proteins (e.g. (wikipedia.org)
  • regulatory
  • The regulatory protein subunits of many ion channels and transmembrane receptors, for example, may be defined as peripheral membrane proteins. (wikipedia.org)
  • It also may involve the formation or dissociation of protein quaternary structures or oligomeric complexes, and specific binding of ions, ligands, or regulatory lipids. (wikipedia.org)
  • These proteins may be anchored to the bilayer as a result of hydrophobic interactions between the bilayer and exposed nonpolar residues at the surface of a protein, by specific non-covalent binding interactions with regulatory lipids , or through their attachment to covalently bound lipid anchors. (wikipedia.org)
  • lipids
  • StAR or STARD1) and lipids like phosphatidylcholine (phosphatidylcholine transfer protein, also called PCTP or STARD2) and have enzymatic activities. (wikipedia.org)
  • vesicles
  • To ensure that these vesicles embark in the right direction and to further organize the cell, special motor proteins attach to cargo-filled vesicles and carry them along the cytoskeleton. (wikipedia.org)
  • Small membrane bound vesicles responsible for transporting proteins from one organelle to another are commonly found in endocytic and secretory pathways. (wikipedia.org)
  • ligands
  • Thousands of proteins containing at least one START domain have been determined in invertebrates, bacteria and plants to form a larger superfamily, variously known as START, Bet v1-like or SRPBCC (START/RHOalphaC/PITP/Bet v1/CoxG/CalC) domain proteins, all of which bind hydrophobic ligands. (wikipedia.org)
  • Representatives of the START domain family bind different substances or ligands such as sterols (e.g. (wikipedia.org)
  • membrane
  • Src tyrosine kinases, Galpha subunits, and H-Ras share a common membrane-anchored scaffolding protein, caveolin. (wikipedia.org)
  • Peripheral membrane proteins are membrane proteins that adhere only temporarily to the biological membrane with which they are associated. (wikipedia.org)
  • These proteins attach to integral membrane proteins, or penetrate the peripheral regions of the lipid bilayer. (wikipedia.org)
  • In contrast to integral membrane proteins, peripheral membrane proteins tend to collect in the water-soluble component, or fraction, of all the proteins extracted during a protein purification procedure. (wikipedia.org)
  • Proteins with GPI anchors are an exception to this rule and can have purification properties similar to those of integral membrane proteins. (wikipedia.org)
  • Membrane binding may also promote rearrangement, dissociation, or conformational changes within many protein structural domains, resulting in an activation of their biological activity. (wikipedia.org)
  • Additionally, the positioning of many proteins are localized to either the inner or outer surfaces or leaflets of their resident membrane. (wikipedia.org)
  • Peripheral membrane proteins may interact with other proteins or directly with the lipid bilayer. (wikipedia.org)
  • These proteins are usually described as peripheral as one of their conformational states is water-soluble or only loosely associated with a membrane. (wikipedia.org)
  • In order to be active, steroid hormones must free themselves from their blood-solubilizing proteins and either bind to extracellular receptors, or passively cross the cell membrane and bind to nuclear receptors. (wikipedia.org)
  • One study has found that these steroid-carrier complexes are bound by megalin, a membrane receptor, and are then taken into cells via endocytosis. (wikipedia.org)
  • domains
  • Ligand binding by the START domain in multidomain proteins can also regulate the activities of the other domains, such as the RhoGAP domain, the homeodomain and the thioesterase domain. (wikipedia.org)
  • Other proteins also exist in the human with domains that are members of the START-based superfamily such as PITP, but are not part of the START domain itself. (wikipedia.org)
  • Human
  • Kino T, Chrousos GP, Human immunodeficiency virus type-1 accessory protein Vpr: a causative agent of the AIDS-related insulin resistance/lipodystrophy syndrome? (wikipedia.org)
  • subunits
  • Immunochemical, molecular sieving, and chemical cross-linking experiments indicated that these isoforms represent thiolytically active homo- and heterodimeric combinations of the 46- and 58-kDa subunits (2 x 58, 58-46, and 2 x 46-kDa proteins). (kuleuven.be)
  • The protein links integrin subunits to the tyrosine kinase FYN, an initiating step in coupling integrins to the Ras-ERK pathway and promoting cell cycle progression. (wikipedia.org)
  • chromosome
  • CAV1 and CAV2 are located next to each other on chromosome 7 and express colocalizing proteins that form a stable hetero-oligomeric complex. (wikipedia.org)
  • bind
  • Some steroid antagonists: Androgen: cyproterone acetate Progestins: mifepristone, gestrinone Steroid hormones are transported through the blood by being bound to carrier proteins-serum proteins that bind them and increase the hormones' solubility in water. (wikipedia.org)