Abstract
Skeletal muscle glycogen a4-synthase (EC 2.4.1.11) has been purified free of all synthase kinase and phosphatase activities by chromatography on a Glc-N-6-P-Sepharose affinity column and then on a phosphocellulose column. This preparation of glycogen synthase was tested as a substrate for purified skeletal muscle phosphorylase kinase (ATP:phosphorylase-b phosphotransferase, EC 2.7.1.38). Phosphorylase kinase (1-10 microgram/ml or 0.03-0.3 microM) catalyzes rapid phosphorylation of glycogen synthase (4.5 microM) associated with conversion of the active a form to the less active b form. In the reaction, greater than 95% of the 32P incorporation from [gamma-32P]ATP goes into the synthase subunit almost exclusively in the trypsin-insensitive region which is responsible for synthase a-to-b conversion. Synthase phosphorylation or inactivations catalyzed by phosphorylase kinase is blocked by ethylene glycol bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, is ATP dependent, is 10-fold more rapid at pH 8.6 than at pH 6.8, and is increased 10-fold by prior activation of the phosphorylase kinase with MgATP and cyclic AMP. With activated phosphorylase kinase at pH 8.2 the apparent Km and Vmax are approximately 70 microM and 4 mumol/min per mg with glycogen synthase and 70 microM and 9 mumol/min per mg with phosphorylase as substrate. It is concluded that glycogen synthase is a substrate in vitro for phosphorylase kinase, a Ca2+-dependent enzyme. The possible physiological significance of this reaction is discussed.
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- Brostrom C. O., Hunkeler F. L., Krebs E. G. The regulation of skeletal muscle phosphorylase kinase by Ca2+. J Biol Chem. 1971 Apr 10;246(7):1961–1967. [PubMed] [Google Scholar]
- Brown J. H., Thompson B., Mayer S. E. Conversion of skeletal muscle glycogen synthase to multiple glucose 6-phosphate dependent forms by cyclic adenosine monophosphate dependent and independent protein kinases. Biochemistry. 1977 Dec 13;16(25):5501–5508. doi: 10.1021/bi00644a017. [DOI] [PubMed] [Google Scholar]
- Cohen P., Burchell A., Foulkes J. G., Cohen P. T., Vanaman T. C., Nairn C. Identification of the Ca2+-dependent modulator protein as the fourth subunit of rabbit skeletal muscle phosphorylase kinase. FEBS Lett. 1978 Aug 15;92(2):287–293. doi: 10.1016/0014-5793(78)80772-8. [DOI] [PubMed] [Google Scholar]
- FISCHER E. H., KREBS E. G. The isolation and crystallization of rabbit skeletal muscle phosphorylase b. J Biol Chem. 1958 Mar;231(1):65–71. [PubMed] [Google Scholar]
- Hayakawa T., Perkins J. P., Walsh D. A., Krebs E. G. Physiochemical properties of rabbit skeletal muscle phosphorylase kinase. Biochemistry. 1973 Feb;12(4):567–573. doi: 10.1021/bi00728a001. [DOI] [PubMed] [Google Scholar]
- Khatra B. S., Soderling T. R. Reversible inhibition of skeletal muscle phosphoprotein phosphatase by ATP, phosphate and fluoride. Biochem Biophys Res Commun. 1978 Nov 29;85(2):647–654. doi: 10.1016/0006-291x(78)91211-1. [DOI] [PubMed] [Google Scholar]
- Krebs E. G., DeLange R. J., Kemp R. G., Riley W. D. Activation of skeletal muscle phosphorylase. Pharmacol Rev. 1966 Mar;18(1):163–171. [PubMed] [Google Scholar]
- Nimmo H. G., Proud C. G., Cohen P. The phosphorylation of rabbit skeletal muscle glycogen synthase by glycogen synthase kinase-2 and adenosine-3':5'-monophosphate-dependent protein kinase. Eur J Biochem. 1976 Sep;68(1):31–44. doi: 10.1111/j.1432-1033.1976.tb10762.x. [DOI] [PubMed] [Google Scholar]
- Piras R., Staneloni R. In vivo regulation of rat muscle glycogen synthetase activity. Biochemistry. 1969 May;8(5):2153–2160. doi: 10.1021/bi00833a056. [DOI] [PubMed] [Google Scholar]
- Roach P. J., DePaoli-Roach A. A., Larner J. Ca2+-stimulated phosphorylation of muscle glycogen synthase by phosphorylase b kinase. J Cyclic Nucleotide Res. 1978 Aug;4(4):245–257. [PubMed] [Google Scholar]
- Roach P. J., Takeda Y., Larner J. Rabbit skeletal muscle glycogen synthase. I. Relationship between phosphorylation state and kinetic properties. J Biol Chem. 1976 Apr 10;251(7):1913–1919. [PubMed] [Google Scholar]
- Schlender K. K., Reimann E. M. Isolation of a glycogen synthase I kinase that is independent of adenosine 3':5'-monophosphate. Proc Natl Acad Sci U S A. 1975 Jun;72(6):2197–2201. doi: 10.1073/pnas.72.6.2197. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Soderling T. R., Jett M. F., Hutson N. J., Khatra B. S. Regulation of glycogen synthase. Phosphorylation specificities of cAMP-dependent and cAMP-independent kinases for skeletal muscle synthase. J Biol Chem. 1977 Nov 10;252(21):7517–7524. [PubMed] [Google Scholar]
- Soderling T. R. Regulation of glycogen synthetase. Effects of trypsin on the structure, activity, and phosphorylation of the skeletal muscle enzyme. J Biol Chem. 1976 Jul 25;251(14):4359–4364. [PubMed] [Google Scholar]
- Soderling T. R. Regulation of glycogen synthetase. Specificity and stoichiometry of phosphorylation of the skeletal muscle enzyme by cyclic 3':5'-AMP-dependent protein kinase. J Biol Chem. 1975 Jul 25;250(14):5407–5412. [PubMed] [Google Scholar]
- Srivastava A. K., Waisman D. M., Brostrom C. O., Soderling T. R. Stimulation of glycogen synthase phosphorylation by calcium-dependent regulator protein. J Biol Chem. 1979 Feb 10;254(3):583–586. [PubMed] [Google Scholar]
- Takeda Y., Larner J. Structural studies on rabbit muscle glycogen synthase. II. Limited proteolysis. J Biol Chem. 1975 Dec 10;250(23):8951–8956. [PubMed] [Google Scholar]
- Walsh D. A., Perkins J. P., Brosom C. O., Ho E. S., Kreb E. G. Catlysis of the phosphrylaseinase actition reaction. J Biol Chem. 1971 Apr 10;246(7):1968–1976. [PubMed] [Google Scholar]