Journal article

Single fiber analyses of glycogen-related proteins reveal their differential association with glycogen in rat skeletal muscle

Robyn M Murphy, Hongyang Xu, Heidy Latchman, Noni T Larkins, Paul R Gooley, David I Stapleton



To understand how glycogen affects skeletal muscle physiology, we examined enzymes essential for muscle glycogen synthesis and degradation using single fibers from quiescent and stimulated rat skeletal muscle. Presenting a shift in paradigm, we show these proteins are differentially associated with glycogen granules. Protein diffusibility and/or abundance of glycogenin, glycogen branching enzyme (GBE), debranching enzyme (GDE), phosphorylase (GP), and synthase (GS) were examined in fibers isolated from rat fast-twitch extensor digitorum longus (EDL) and slow-twitch soleus (SOL) muscle. GDE and GP proteins were more abundant (~10- to 100-fold) in fibers from EDL compared with SOL muscle. GS a..

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University of Melbourne Researchers


Awarded by National Health and Medical Research Council of Australia

Awarded by Australian Research Council

Funding Acknowledgements

The monoclonal antibody directed against SERCA1 were developed by Dr. D. Fambrough and obtained from the Development Studies Hybridoma Bank, under the auspices of the National Institute of Child Health and Human Development and maintained by the University of Iowa, Department of Biological Sciences. We thank Simon Masser for technical assistance in preparing the GBE protein and Maria Cellini for technical assistance.This study was supported by the National Health and Medical Research Council of Australia (628698 to D. Stapleton) and Australian Research Council (DP110103161; to P. Gooley, D. Stapleton, and R. Murphy).