| Literature DB >> 20713714 |
Ho-Jin Koh1, Taro Toyoda, Nobuharu Fujii, Michelle M Jung, Amee Rathod, R Jan-Willem Middelbeek, Sarah J Lessard, Jonas T Treebak, Katsuya Tsuchihara, Hiroyasu Esumi, Erik A Richter, Jørgen F P Wojtaszewski, Michael F Hirshman, Laurie J Goodyear.
Abstract
The signaling mechanisms that mediate the important effects of contraction to increase glucose transport in skeletal muscle are not well understood, but are known to occur through an insulin-independent mechanism. Muscle-specific knockout of LKB1, an upstream kinase for AMPK and AMPK-related protein kinases, significantly inhibited contraction-stimulated glucose transport. This finding, in conjunction with previous studies of ablated AMPKalpha2 activity showing no effect on contraction-stimulated glucose transport, suggests that one or more AMPK-related protein kinases are important for this process. Muscle contraction increased sucrose nonfermenting AMPK-related kinase (SNARK) activity, an effect blunted in the muscle-specific LKB1 knockout mice. Expression of a mutant SNARK in mouse tibialis anterior muscle impaired contraction-stimulated, but not insulin-stimulated, glucose transport. Whole-body SNARK heterozygotic knockout mice also had impaired contraction-stimulated glucose transport in skeletal muscle, and knockdown of SNARK in C2C12 muscle cells impaired sorbitol-stimulated glucose transport. SNARK is activated by muscle contraction and is a unique mediator of contraction-stimulated glucose transport in skeletal muscle.Entities:
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Year: 2010 PMID： 20713714 PMCID： PMC2932588 DOI： 10.1073/pnas.1008131107
Source DB: PubMed Journal: Proc Natl Acad Sci U S A ISSN： 0027-8424 Impact factor: 11.205