Tags: Protein.
The steroidogenic acute regulatory protein commonly referred to as StAR (STARD1) is a transport protein that regulates cholesterol transfer within the mitochondria which is the rate-limiting step in the production of steroid hormones. It is primarily present in steroid-producing cells including theca cells and luteal cells in the ovary Leydig cells in the testis and cell types in the adrenal cortex.