Association of acyl-CoA synthetase-1 with GLUT4-containing vesicles

J Biol Chem. 1998 Feb 6;273(6):3132-5. doi: 10.1074/jbc.273.6.3132.

Abstract

GLUT4, the glucose transporter present in insulin-sensitive tissues, resides in intracellular vesicular structures and translocates to the cell surface in response to insulin. In an attempt to identify proteins present in these structures, GLUT4-enriched vesicles prepared from rat adipocytes treated with or without insulin were prepared by sucrose velocity gradient centrifugation and immunoadsorbed with anti-GLUT4 antibody. We report here the sequence identification by high performance liquid chromatography-ion trap mass spectrometry of a p75 protein band, long chain acyl-CoA synthetase-1, specifically present in immunoadsorbed GLUT4-containing vesicles but not in vesicles adsorbed by nonimmune serum. Acyl-CoA synthetase activity detected in GLUT4-enriched vesicles prepared by gradient centrifugation from insulin-treated adipocytes was decreased to about the same extent as GLUT4 protein. Additionally, immunoadsorbed GLUT4 vesicles were found to catalyze palmitoylation of proteins when incubated with labeled palmitate, a pathway that requires palmitate esterification with CoA. These data indicate that the insulin-sensitive membrane compartment that sequesters GLUT4 in fat cells contains long chain acyl-CoA synthetase-1 and its product fatty acyl-CoA, shown previously to be required for budding and fusion in membrane trafficking processes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acyl Coenzyme A / metabolism
  • Adipocytes / enzymology*
  • Adipocytes / ultrastructure
  • Amino Acid Sequence
  • Animals
  • Coenzyme A Ligases / metabolism*
  • Glucose Transporter Type 4
  • Male
  • Membrane Fusion
  • Microscopy, Electron
  • Monosaccharide Transport Proteins / metabolism*
  • Muscle Proteins*
  • Rats
  • Rats, Sprague-Dawley
  • Repressor Proteins*
  • Saccharomyces cerevisiae Proteins*

Substances

  • Acyl Coenzyme A
  • Glucose Transporter Type 4
  • Monosaccharide Transport Proteins
  • Muscle Proteins
  • Repressor Proteins
  • Saccharomyces cerevisiae Proteins
  • Slc2a4 protein, rat
  • Coenzyme A Ligases
  • FAA2 protein, S cerevisiae
  • long-chain-fatty-acid-CoA ligase