GRAMD1B Cholesterol transporter that mediates non-vesicular transport of cholesterol from the plasma membrane (PM) to the endoplasmic reticulum (ER). Contains unique domains for binding cholesterol and the PM, thereby serving as a molecular bridge for the transfer of cholesterol from the PM to the ER. Plays a crucial role in cholesterol homeostasis in the adrenal gland and has the unique ability to localize to the PM based on the level of membrane cholesterol. In lipid-poor conditions localizes to the ER membrane and in response to excess cholesterol in the PM is recruited to the endoplasmic reticulum-plasma membrane contact sites (EPCS) which is mediated by the GRAM domain. At the EPCS, the sterol-binding VASt/ASTER domain binds to the cholesterol in the PM and facilitates its transfer from the PM to ER. 4 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Membrane protein, integral
Chromosomal Location of Human Ortholog: 9|9 A5.1
Cellular Component:  endoplasmic reticulum; endoplasmic reticulum membrane; integral component of membrane; membrane; plasma membrane
Molecular Function:  cholesterol binding; intermembrane cholesterol transfer activity; lipid binding; phosphatidic acid binding; phosphatidylserine binding
Biological Process:  cellular response to cholesterol; cholesterol homeostasis; lipid transport
Reference #:  Q80TI0 (UniProtKB)
Alt. Names/Synonyms: 3222402H23; A930008A22Rik; AI593249; GRAM domain containing 1B; GRAM domain-containing protein 1B; Gramd1b; GRM1B; Kiaa1201; mKIAA1201
Gene Symbols: Gramd1b
Molecular weight: 85,355 Da
Basal Isoelectric point: 5.79  Predict pI for various phosphorylation states
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Protein Structure Not Found.

Cross-references to other databases:  STRING  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene