First Author | Treebak JT | Year | 2006 |
Journal | Diabetes | Volume | 55 |
Issue | 7 | Pages | 2051-8 |
PubMed ID | 16804075 | Mgi Jnum | J:111858 |
Mgi Id | MGI:3654973 | Doi | 10.2337/db06-0175 |
Citation | Treebak JT, et al. (2006) AMPK-mediated AS160 phosphorylation in skeletal muscle is dependent on AMPK catalytic and regulatory subunits. Diabetes 55(7):2051-8 |
abstractText | AMP-activated protein kinase (AMPK) is a heterotrimeric protein that regulates glucose transport mediated by cellular stress or pharmacological agonists such as 5-aminoimidazole-4-carboxamide 1 beta-d-ribonucleoside (AICAR). AS160, a Rab GTPase-activating protein, provides a mechanism linking AMPK signaling to glucose uptake. We show that AICAR increases AMPK, acetyl-CoA carboxylase, and AS160 phosphorylation by insulin-independent mechanisms in isolated skeletal muscle. Recombinant AMPK heterotrimeric complexes (alpha1beta1gamma1 and alpha2beta2gamma1) phosphorylate AS160 in a cell-free assay. In mice deficient in AMPK signaling (alpha2 AMPK knockout [KO], alpha2 AMPK kinase dead [KD], and gamma3 AMPK KO), AICAR effects on AS160 phosphorylation were severely blunted, highlighting that complexes containing alpha2 and gamma3 are necessary for AICAR-stimulated AS160 phosphorylation in intact skeletal muscle. Contraction-mediated AS160 phosphorylation was also impaired in alpha2 AMPK KO and KD but not gamma3 AMPK KO mice. Our results implicate AS160 as a downstream target of AMPK. |