A Review of the Characteristics of the Protein Required for the Acute Regulation of Steroid Hormone Biosynthesis: The Case for the Steroidogenic Acute Regulatory (StAR) Protein

The acute regulation of steroid hormone biosynthesis requires the de novo synthesis of a protein whose function is to effect the transfer of cholesterol from the outer to the inner mitochondrial membrane where it is cleaved to pregnenolone. This review attempts to summarize the list of this protein's characteristics, which have emerged as a result of experimental observations, and to make the case that the Steroidogenic Acute Regulatory (StAR) Protein is the acute regulator of steroid hormone synthesis.