StAR-related lipid transfer protein 5 (STARD5)

StAR-related lipid transfer protein 5 (STARD5) is a cytosolic lipid transfer protein, highly expressed in liver, kidney, and immune cells (notably Kupffer cells and macrophages), that binds and transports cholesterol and its derivatives (e.g., 25-hydroxycholesterol) between intracellular membranes, such as from the cytoplasm to the endoplasmic reticulum and Golgi apparatus. Structurally, it contains a START domain, which forms a hydrophobic cavity for binding sterol molecules. STARD5 is upregulated in response to endoplasmic reticulum (ER) stress and functions to maintain intracellular and plasma membrane cholesterol homeostasis. Knockout studies in mice show that loss of STARD5 results in reduced plasma membrane cholesterol, altered cholesterol efflux, accumulation of intracellular lipids in macrophages, and increased hepatic triglycerides and cholesterol content, suggesting a key role in non-vesicular sterol transport and cell membrane cholesterol regulation. Despite broad interest in cellular cholesterol trafficking and homeostasis, STARD5 is not at present a direct therapeutic target or established disease biomarker.

Other names

StAR-related lipid transfer domain containing 5STARD5StARD5MGC10327START domain-containing protein 5stAR-related lipid transfer protein 5START domain containing 5StAR-related lipid transfer (START) domain containing 5

Not applicable (no drugs or tool compounds known to target STARD5)