Perilipins are associated with cholesteryl ester droplets in steroidogenic adrenal cortical and Leydig cells

J Biol Chem. 1995 Jul 14;270(28):16970-3. doi: 10.1074/jbc.270.28.16970.

Abstract

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.

MeSH terms

  • 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*

Substances

  • Carrier Proteins
  • Cholesterol Esters
  • Perilipin-1
  • Phosphoproteins
  • RNA, Messenger
  • Steroids