How is steroid hormone production acutely regulated? This review delves into the role of the steroidogenic acute regulatory (StAR) protein, a crucial component in steroid hormone biosynthesis. It explores how StAR facilitates cholesterol translocation within mitochondria, the rate-limiting step in hormone formation. Understanding StAR's function is vital to elucidating the complex mechanisms governing hormone production. The paper examines the expression and indispensable role of StAR, highlighting its sensitivity to steroidogenic stimuli. The authors discuss how mutations in the StAR gene lead to congenital lipoid adrenal hyperplasia, a severe disruption of steroid hormone biosynthesis. Furthermore, they explore the mechanism of cholesterol transfer and examine the tertiary structure of the START domain, positing that StAR acts as a cholesterol-shuttling protein. This comprehensive review not only consolidates existing knowledge but also identifies key areas for future research, such as further characterizing the mechanisms by which StAR mediates cholesterol transfer and investigating its potential as a therapeutic target for hormonal disorders.
Published in the Annual Review of Physiology, this paper aligns perfectly with the journal's focus on in-depth analyses of physiological processes. The review provides a comprehensive overview of StAR protein's role in steroid hormone biosynthesis, fitting the journal's scope of covering key advances in physiological research. Its relevance to biochemistry further strengthens its place within the journal's target topics.