Activation of Protein Kinase C Mediates Insulin Regulation of the Na-K Pump in Cultured Skeletal Muscle
At first glance, the inclusion of this lecture in this symposium might seem to be a bit superfluous -what possible connection is there between regulation of Na+ -K+ pump activity in skeletal muscle and control of the respiratory and cardiovascular systems? A brief reflection will, of course, provide the answer. Skeletal muscle represents approximately 40% of the body weight and is a major source of K+. Indeed, during muscle exercise muscle activity can lead to a doubling of [K+]o, and a responsive and active Na+ -K+ pump is absolutely essential for continued muscle and cardiovascular function. In addition, the pump plays an important role in control of cardiac and smooth muscle function. Hence, knowledge of the regulatory and signaling mechanisms involved in Na+ -K+ pump activity may also provide information regarding important regulatory mechanisms of respiratory and cardiovascular activity.
KeywordsHydrolysis Glycerol Albumin EDTA Trypsin
Unable to display preview. Download preview PDF.
- 6.Chibalin, A. V., L. A. Vasilets, H. Hennekes, D. Pralong, and K. Geering. Phosphorylation of Na, K-ATPase α-subunits in microsomes and in homogenates of Xenopus oocytes resulting from the stimulation of protein kinase A and protein kinase C. J. Biol. Chem. 267: 22378–22384.Google Scholar
- 10.Erlij, D. and S. Grinstein. The number of sodium ion pumping sites in skeletal muscle and its modification by insulin. J. Physiol. (Lond.). 259: 13–31, 1976.Google Scholar
- 13.Hecht, L.B. and D.S. Straus. Insulin-stimulated protein kinase activity in rat skeletal muscle that phosphorylates ribosomal protein S6. Bioch. Biophys. Res. Comm. 152: 1200–1206.Google Scholar
- 15.Hootman, S.R., and S.A. Ernst. Estimation of Na+/K+-pump numbers and turnover in intact cells with [3H]-ouabain. In: Methods in Enzymology: Biomembranes and Biological Transport, edited by S. Fleischer and B. Fleischer. New York, Academic, 1988.Google Scholar
- 16.Hundal, H.S., A. Marette, Y. Mitsumoto, T. Ramlal, R. Blostein, and A. Klip. Insulin induces translocation of the a2 and ß1 subunits of the Na+/K+-ATPase from intracellular compartments to the plasma membrane in mammalian skeletal muscle. J. Biochem. Chem. 267: 5040–5043, 1992.Google Scholar
- 20.Lowndes, J.M., M. Hokin-Neaverson, and P.J. Bertics. Kinetics of phosphorylation of Na+/K+-ATPase by protein kinase C. Biochim. Biophys. Acta, 1052: 143–151, 1990.Google Scholar
- 25.Omatsu-Kanabe, M., and Kitasato, H. Insulin stimulates the translocation of Na+/K+-dependent ATPase molecules from intracellular stores to the plasma membrane in frog skeletal muscle. Biochem. J. 272: 727–733, 1990.Google Scholar