Role of AMP-activated Protein Kinase in Cyclic AMP-dependent Lipolysis in 3T3-L1 Adipocytes

  • Yin W
  • Mu J
  • Birnbaum M
  • 67

    Readers

    Mendeley users who have this article in their library.
  • 194

    Citations

    Citations of this article.

Abstract

AMP-activated protein kinase (AMPK) is a phylogenetically conserved intracellular energy sensor that has been implicated as a major regulator of glucose and lipid metabolism in mammals. However, its possible role in mediating or influencing the adrenergic control of lipolysis in adipocytes remains uncertain. In this study, we utilized the murine cultured preadipocyte line 3T3-L1 to examine this question. Treatment of adipocytes with isoproterenol or forskolin promoted the phosphorylation of AMPK at a critical activating Thr-172 residue in a dose- and time-dependent manner. This correlated well with a stimulation of the activity of AMPK, as measured in the immune complex. Analogs of cAMP mimicked the effect of isoproterenol and forskolin on AMPK phosphorylation. Treatment of adipocytes with insulin reduced both basal and forskolin-induced AMPK phosphorylation via a pathway dependent on phosphatidylinositol 3'-kinase. Overexpression of a dominant-inhibitory mutant of AMPK blocked isoproterenol-induced lipolysis by approximately 50%. These data indicate that there exists a novel pathway by which cAMP can lead to the activation of AMPK, and in adipocytes, this is required for maximal activation of lipolysis.

Get free article suggestions today

Mendeley saves you time finding and organizing research

Sign up here
Already have an account ?Sign in

Find this document

Authors

Cite this document

Choose a citation style from the tabs below

Save time finding and organizing research with Mendeley

Sign up for free