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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
14
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pubmed:dateCreated |
1975-10-10
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pubmed:abstractText |
Complete conversion of skeletal muscle glycogen synthetase from the I form to the D form requires incorporation of 2 mol of phosphate per enzyme subunit (90,000 g). Incubation of sythetase I with low concentrations of adenosine 3':5'-monophosphate(cAMP)-dependent protein kinase (10 units/ml) and ATP (0.1 to 0.3 mM) plus magnesium acetate (10 mM) results in incorporation within 1/2 hour of 1 mol of phosphate persubunit concomitant with a decrease in the synthetase activity ratio (minus glucose-6-P/plus glucose-6-P) from 0.85 to 0.25. Further incubation for 6 hours does not greatly increase the phosphate content of the synthetase or promote conversion to the D form. This level of phosphorylation is not increased by raising the concentration of protein kinase to 150 units/ml and is not influenced by the presence of glucose-6-P, UDP-glucose, or glycogen. However, at protein kinase concentrations of 10,000 to 30,000 units/ml a second mol of phosphate is incorporated per subunit, and the sythetase activity ratio decreases to 0.05 or less. In addition to the 2 mol of phosphate persubunit which are required for formation of sythetase D, further phosphorylation can be observed which is not associated with changes in synthetase activity. This phosphorylation occurs at a slow rate, is increased by raising the ATP concentration to 2 to 4mM, and is not blocked by the heat-stable protein inhibitor of cAMP-dependent protein kinase. These data indicate that skeletal muscle glycogen synthetase contains multiple phosphorylation sites only two of which are involved in the synthetase I to D conversion.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Adenosine Triphosphate,
http://linkedlifedata.com/resource/pubmed/chemical/Cyclic AMP,
http://linkedlifedata.com/resource/pubmed/chemical/Fluorides,
http://linkedlifedata.com/resource/pubmed/chemical/Glycogen Synthase,
http://linkedlifedata.com/resource/pubmed/chemical/Magnesium,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphates,
http://linkedlifedata.com/resource/pubmed/chemical/Phosphorus Radioisotopes,
http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases
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pubmed:status |
MEDLINE
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pubmed:month |
Jul
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pubmed:issn |
0021-9258
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
25
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pubmed:volume |
250
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
5407-12
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pubmed:dateRevised |
2009-11-19
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pubmed:meshHeading |
pubmed-meshheading:167014-Adenosine Triphosphate,
pubmed-meshheading:167014-Animals,
pubmed-meshheading:167014-Cyclic AMP,
pubmed-meshheading:167014-Electrophoresis, Disc,
pubmed-meshheading:167014-Fluorides,
pubmed-meshheading:167014-Glycogen Synthase,
pubmed-meshheading:167014-Magnesium,
pubmed-meshheading:167014-Muscles,
pubmed-meshheading:167014-Phosphates,
pubmed-meshheading:167014-Phosphorus Radioisotopes,
pubmed-meshheading:167014-Protein Kinases,
pubmed-meshheading:167014-Rabbits,
pubmed-meshheading:167014-Radioligand Assay
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pubmed:year |
1975
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pubmed:articleTitle |
Regulation of glycogen synthetase. Specificity and stoichiometry of phosphorylation of the skeletal muscle enzyme by cyclic 3':5'-AMP-dependent protein kinase.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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