Linked Life Data

7671134

Source:http://linkedlifedata.com/resource/pubmed/id/7671134

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1995-10-17
pubmed:abstractText
The regulation of cardiac muscle glycogen metabolism is not well understood. Previous studies have indicated that heart glycogen synthase is heavily phosphorylated in vivo on multiple sites. Using purified enzymes, we have investigated the effect of phosphorylation of different sites on the activity of rat heart glycogen synthase. A convenient procedure was developed for the purification of rat heart glycogen synthase. The enzyme was phosphorylated by selected kinases, and glycogen synthase activity, extent of phosphorylation, and phosphopeptide maps were analyzed. Rat heart glycogen synthase, purified to apparent homogeneity (M(r) 87,000 on SDS-PAGE), had a specific activity of 18 U/mg protein and had an activity ratio of 0.74 (activity in the absence divided by the activity in the presence of glucose 6-P). cAMP-dependent protein kinase, glycogen synthase kinase 3, Ca2+/calmodulin-dependent protein kinase II, protein kinase C, and phosphorylase kinase phosphorylated the enzyme with a concomitant decrease in the activity ratio to values ranging from 0.1 to 0.4. Casein kinase II phosphorylated but did not inactivate glycogen synthase. Six tryptic phosphopeptides, obtained from heart glycogen synthase phosphorylated by the various kinases, were separated by reverse-phase chromatography. The phosphopeptide(s) obtained with each kinase eluted at the same position(s) as corresponding phosphopeptides obtained from rat skeletal muscle glycogen synthase. The study shows that the pattern of phosphorylation and effects on activity are very similar for cardiac and skeletal muscle glycogen synthase. It is suggested that the well known differences in heart and glycogen metabolism may be due to the interplay of kinases and phosphatases which could lead to different phosphorylation and activity states of glycogen synthase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
1357-2725
pubmed:author
pubmed:issnType
Print
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
565-73
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:7671134-Animals, pubmed-meshheading:7671134-Chromatography, Affinity, pubmed-meshheading:7671134-Chromatography, High Pressure Liquid, pubmed-meshheading:7671134-Chromatography, Ion Exchange, pubmed-meshheading:7671134-Cyanogen Bromide, pubmed-meshheading:7671134-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:7671134-Glycogen, pubmed-meshheading:7671134-Glycogen Synthase, pubmed-meshheading:7671134-Male, pubmed-meshheading:7671134-Molecular Weight, pubmed-meshheading:7671134-Myocardium, pubmed-meshheading:7671134-Peptide Fragments, pubmed-meshheading:7671134-Phosphorylase Kinase, pubmed-meshheading:7671134-Phosphorylation, pubmed-meshheading:7671134-Protein Kinases, pubmed-meshheading:7671134-Protein-Serine-Threonine Kinases, pubmed-meshheading:7671134-Rats, pubmed-meshheading:7671134-Trypsin
pubmed:year
1995
pubmed:articleTitle
Phosphorylation and inactivation of rat heart glycogen synthase by cAMP-dependent and cAMP-independent protein kinases.
pubmed:affiliation
Department of Pharmacology, Medical College of Ohio, Toledo 43699, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't