Effect of insulin on the phosphorylation of adipose tissue protein

https://doi.org/10.1016/0005-2795(74)90063-4Get rights and content

Abstract

Although insulin has profound metabolic effects, only some of these may be explained by modulation of adenosine 3′:5′-cyclic monophosphate (cyclic AMP) levels. Therefore, the effects of insulin on fat cell protein metabolism were studied under conditions which are not associated with changes in cyclic AMP levels. Both rat epididymal fat pad and isolated fat cells were used to study insulin-induced [32P]orthophosphate or [35S]methionine incorporation into sodium dodecyl sulfate-soluble proteins and/or polypeptides isolated by acrylamide slab gel electrophoresis and high resolution autoradiography. Insulin specifically increased the incorporation of [32P]orthophosphate into a high molecular weight protein (about 140 000 mol.wt). This phosphorylation occurred: (1) in both fat pads and isolated fat cells; (2) at physiological insulin concentrations (40 μunits/ml); (3) within 15 min after insulin addition; (4) in the absence of glucose; and (5) was partially antagonized by epinephrine (10−5 M). Thus, physiological insulin concentrations specifically induced the in vitro phosphorylation of a high molecular weight protein, in a manner consistent with the physiological action of insulin in vivo, and under conditions not associated with changes in cyclic AMP levels.

References (41)

  • R.W. Butcher et al.

    J. Biol. Chem.

    (1966)
  • L.S. Jefferson et al.

    J. Biol. Chem.

    (1968)
  • J.H. Exton et al.

    Adv. Eng. Reg.

    (1968)
  • R.W. Butcher et al.

    J. Biol. Chem.

    (1968)
  • V.C. Manganiello et al.

    J. Biol. Chem.

    (1971)
  • G.G. Majumder et al.

    J. Biol. Chem.

    (1971)
  • M. Rodbell et al.

    J. Biol. Chem.

    (1973)
  • J.V. Maizel
  • G. Fairbanks et al.

    Biochem. Biophys. Res. Commun.

    (1965)
  • A.I. Winegrad et al.

    J. Biol. Chem.

    (1958)
  • M. Rodbell

    J. Biol. Chem.

    (1964)
  • O.H. Lowry et al.

    J. Biol. Chem.

    (1951)
  • K. Weber et al.

    J. Biol. Chem.

    (1969)
  • S.E. Allerton et al.

    J. Biol. Chem.

    (1965)
  • S. Roseman
  • J.S. Bishop et al.

    J. Biol. Chem.

    (1967)
  • J.C. Khoo et al.

    J. Biol. Chem.

    (1973)
  • T. Egelrud et al.

    J. Biol. Chem.

    (1972)
  • M.A. Rizack

    J. Biol. Chem.

    (1964)
  • J.C. Khoo et al.

    J. Biol. Chem.

    (1972)

    • Cited by (0)

    View full text
    Copyright © 1974 Published by Elsevier B.V.