Oxysterol-binding protein homolog 4

UniProtKB accession:  P35844

Grouped By:  Matching UniProtKB accession

UniProtKB description:  Lipid transport protein (LTP) involved in non-vesicular transfer of lipids between membranes. Functions in phosphoinositide-coupled directional transport of various lipids by carrying the lipid molecule in a hydrophobic pocket and transferring it between membranes through the cytosol. Involved in maintenance of intracellular sterol distribution and homeostasis (PubMed:15173322, PubMed:16136145, PubMed:20008566, PubMed:22162133). Involved in lipid countertransport between the Golgi complex and membranes of the endoplasmic reticulum. Specifically exchanges sterol with phosphatidylinositol 4-phosphate (PI4P), delivering sterol to the Golgi in exchange for PI4P, which is delivered to the ER-localized PI4P phosphatase SAC1 for degradation. Thus, by maintaining a PI4P gradient at the ER/Golgi interface, SAC1 may drive PS transport (PubMed:16136145, PubMed:22162133, PubMed:25849868). Displays a similar affinity for PI4P and sterols (PubMed:22162133). Binds sterol and PI4P in a mutually exclusive manner (PubMed:22162133). Involved in ergosterol transport from the plasma membrane (PM) to the ER (PubMed:16585271). Mediates sterol transport from the ER to mitochondria (PubMed:29487131). Involved in the negative regulation of Golgi-derived transport vesicle biogenesis (PubMed:8978672). Plays a role in the positive regulation of vesicular transport of ceramide from the ER to the Golgi, negatively regulating COPII-mediated ER export of cargos (PubMed:24213531).