Linked Life Data

2985384

Source:http://linkedlifedata.com/resource/pubmed/id/2985384

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1985-6-17
pubmed:abstractText
The phosphorylase phosphatases in rat and rabbit liver cytosol that are markedly stimulated by histone H1, protamine and polylysine were identified as protein phosphatases-2A0, 2A1 and 2A2 by anion-exchange chromatography, gel-filtration and immunotitration experiments. Histone H1 and protamine also stimulated the dephosphorylation of phosphorylase kinase, glycogen synthase, fructose-1,6-bisphosphatase, pyruvate kinase, acetyl-CoA carboxylase and phenylalanine hydroxylase by phosphatases-2A1 and 2A2, and with several of these substrates activation was even more striking (20-100-fold) than that observed with phosphorylase (approximately 5-fold). Activation by basic polypeptides did not involve dissociation of these phosphatases to the free catalytic subunit. The dephosphorylation of phosphorylase by protein phosphatase-1 was suppressed by basic polypeptides, protamine and polylysine being the most potent inhibitors. However, the dephosphorylation of glycogen synthase, pyruvate kinase and acetyl-CoA carboxylase were markedly stimulated by histone H1 and protamine (2-13-fold). Consequently, with the appropriate substrates, protein phosphatase-1 can also be regarded as a basic-polypeptide-activated protein phosphatase. Heparin stimulated (1.5-2-fold) the dephosphorylation of phosphorylase by phosphatases-2A0 and 2A1, provided that Mn2+ was present, but phosphatase-2A2 and the free catalytic subunit of phosphatase-2A were unaffected. Heparin, in conjunction with Mn2+, also stimulated (1.5-fold) the dephosphorylation of glycogen synthase (labelled in sites 3 abc), phosphorylase kinase and phenylalanine hydroxylase by phosphatase-2A1, but not by phosphatase-2A2. By contrast, the dephosphorylation of phosphorylase and phosphorylase kinase by protein phosphatase-1 was inhibited by heparin. However, dephosphorylation of glycogen synthase and pyruvate kinase by phosphatase-1 was stimulated by this mucopolysaccharide. The studies demonstrate that basic proteins can be used to distinguish protein phosphatase-1 from protein phosphatase-2A, but only if phosphorylase is employed as substrate. Optimal differentiation of the two phosphatases is observed at 30 micrograms/ml protamine or at heparin concentrations greater than 150 microM.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
148
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
245-51
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed-meshheading:2985384-Animals, pubmed-meshheading:2985384-Chemical Phenomena, pubmed-meshheading:2985384-Chemistry, pubmed-meshheading:2985384-Chromatography, Gel, pubmed-meshheading:2985384-Chromatography, Ion Exchange, pubmed-meshheading:2985384-Cytosol, pubmed-meshheading:2985384-Enzyme Activation, pubmed-meshheading:2985384-Female, pubmed-meshheading:2985384-Heparin, pubmed-meshheading:2985384-Histones, pubmed-meshheading:2985384-Liver, pubmed-meshheading:2985384-Peptides, pubmed-meshheading:2985384-Phosphoprotein Phosphatases, pubmed-meshheading:2985384-Phosphorylase Phosphatase, pubmed-meshheading:2985384-Polylysine, pubmed-meshheading:2985384-Protamines, pubmed-meshheading:2985384-Protein Phosphatase 1, pubmed-meshheading:2985384-Protein Phosphatase 2, pubmed-meshheading:2985384-Rabbits, pubmed-meshheading:2985384-Rats, pubmed-meshheading:2985384-Rats, Inbred Strains
pubmed:year
1985
pubmed:articleTitle
The protein phosphatases involved in cellular regulation. 1. Modulation of protein phosphatases-1 and 2A by histone H1, protamine, polylysine and heparin.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't