The life cycle of the steroidogenic acute regulatory (StAR) protein: from transcription through proteolysis.

The Steroidogenic Acute Regulatory (StAR) protein is a mitochondrial protein required for the transport of cholesterol substrate to the P450scc enzyme located in the inner mitochondrial membranes of steroid producing cells. This study suggests that the acute regulation of the rodent StAR gene in the ovary is mediated by two factors, C/EBPbeta and GATA-4. Once translated, the StAR precursor protein is either imported into the mitochondria, or it is rapidly degraded in the cytosol.