Sucrose nonfermenting AMPK-related kinase (SNARK) mediates contraction-stimulated glucose transport in mouse skeletal muscle

HJ Koh, T Toyoda, N Fujii, MM Jung… - Proceedings of the …, 2010 - National Acad Sciences
HJ Koh, T Toyoda, N Fujii, MM Jung, A Rathod, RJW Middelbeek, SJ Lessard, JT Treebak…
Proceedings of the National Academy of Sciences, 2010National Acad Sciences
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 AMPKα2
activity showing no effect on contraction-stimulated glucose transport, suggests that one or …
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 AMPKα2 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.
National Acad Sciences