Perilipins Are Associated with Cholesteryl Ester Droplets in Steroidogenic Adrenal Cortical and Leydig Cells

• Published in: The Journal of biological chemistry Vol. 270; no. 28; pp. 16970 - 16973
• Main Authors: Servetnick, Diane A., Brasaemle, Dawn L., Gruia-Gray, Jasmine, Kimmel, Alan R., Wolff, J., Londos, Constantine
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 14.07.1995; American Society for Biochemistry and Molecular Biology
• Subjects: 3T3 Cells; Adipose Tissue - metabolism; Adrenal Cortex - chemistry; Adrenal Cortex - cytology; Animals; Carrier Proteins; Cells, Cultured; Cholesterol Esters - analysis; Leydig Cells - chemistry; Lipid Metabolism; Male; Mice; Perilipin-1; Phosphoproteins - analysis; RNA, Messenger - analysis; Steroids - biosynthesis
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.270.28.16970

Steroidogenic cells store cholesteryl esters, precursors for steroid hormone synthesis, in intracellular lipid droplets. Cholesteryl ester hydrolysis is activated by protein kinase A and catalyzed by cholesteryl esterase. The esterase is similar, if not identical, to hormone-sensitive lipase in adipocytes where an analogous lipolytic mechanism occurs. Perilipins, proteins located exclusively at lipid droplet surfaces in adipocytes, are polyphosphorylated by protein kinase A in response to lipolytic stimuli, suggesting a role for these proteins in mediating lipid metabolism. The present study reveals that perilipins are associated with cholesteryl ester droplets in two steroidogenic cell lines: Y-1 adrenal cortical cells and MA-10 Leydig cells. The relative abundance of perilipin mRNAs and protein is much less in steroidogenic cells than in adipocytes. Like adipocytes, steroidogenic cells express perilipin A; additionally, the latter cells contain relatively abundant amounts of perilipin C, a protein that is not detectable in adipocytes by Western analysis. The data suggest a strong link between perilipins and lipid hydrolysis that is mediated by the hormone-sensitive lipase/cholesteryl esterase class of enzymes.