Cholesterol transport across mitochondrial membranes

Cholesterol transport across mitochondrial membranes is a tightly regulated, multistep process, essential for steroid hormone biosynthesis, mitochondrial function, and cell survival. The process begins with the movement of cholesterol from the endoplasmic reticulum to the mitochondrial outer membrane, mediated at membrane contact sites such as the mitochondria-associated membrane (MAM)[6]. Key mitochondrial proteins include the steroidogenic acute regulatory protein (StAR/STARD1), which shuttles cholesterol to the inner mitochondrial membrane, and the translocator protein (TSPO), a high-affinity cholesterol binding protein[1][2][4][5]. Channel proteins like VDAC1 and Tom40 contribute to the formation of larger protein complexes (the "transduceosome" and "steroidogenic metabolon") that facilitate cholesterol transfer to the inner membrane, where cytochrome P450 enzymes (notably CYP11A1) convert cholesterol to pregnenolone, initiating steroid synthesis[1][3][4][5]. Cholesterol transport dysfunction is increasingly recognized in pathologies such as cancer, neurodegeneration, and metabolic diseases, often due to altered levels or function of these component proteins[4]. While the pathway is therapeutically interesting, only molecules such as TSPO (targeted by TSPO ligands) and StAR are currently directly druggable. If you are looking for structured information on a specific molecular target within this pathway, such as "Steroidogenic acute regulatory protein (StAR/STARD1)" or "Translocator protein (TSPO)," please provide the specific protein or gene name.

Other names

Mitochondrial cholesterol importMitochondrial cholesterol traffickingMitochondrial cholesterol transport

Modulation of cholesterol transfer into mitochondria (e.g., TSPO ligands alter cholesterol binding/allosteric regulation, StAR regulation can alter flux) Regulation of steroid hormone synthesis