Linked Life Data

3001744

Source:http://linkedlifedata.com/resource/pubmed/id/3001744

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-2-10
pubmed:abstractText
An aortic phosphatase which dephosphorylates several proteins including phosphorylase a and the 20-kDa myosin light chains is subject to modulation in vitro by polycationic effectors such as lysine-rich histone-H1 and polylysine. This study was based on the hypothesis that polycationic modulation of expressed enzymic activity involves interactions between the effectors and a regulatory site associated with the polycation-modulated (PCM)-phosphatase. Basal PCM-phosphatase activity expressed against myocardial myosin light chains (MLC, 1258 nmole/min/mg) was about eightfold greater than activity expressed against phosphorylase a (149 nmole/min/mg). However, dephosphorylation of phosphorylase a was stimulated four- to sevenfold by low concentrations of polylysine (Mr = 13,000; 0.01-0.1 microM), whereas MLC phosphatase activity was virtually abolished. Higher concentrations of polylysine inhibited dephosphorylation of either substrate. Interestingly, a heat-stable fraction prepared from the PCM-phosphatase reversed the stimulatory effect of polylysine on phosphorylase phosphatase activity and the inhibitory effect on dephosphorylation of MLC. No reversal of the modulatory effects of polylysine occurred when protein phosphatase inhibitor 1 or inhibitor 2 was substituted for the heat-stable factor derived from the PCM-phosphatase. Sucrose density centrifugation of the enzyme yielded a single peak (Mr = 63,000) exhibiting polycation-modulated activity against phosphorylase a and MLC. Moreover, heating each of the gradient fractions showed the presence of a heat-stable factor which reversed the modulatory effects of polylysine on dephosphorylation of either phosphorylase a or MLC. These results show that a specific heat-stable factor, which differs from both inhibitor 1 and 2, is associated with the PCM-phosphatase. The results suggest that polycationic modulation of expressed PCM-phosphatase activity may involve interactions between the polycationic effector and the enzyme-associated regulatory factor.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Carrier Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Intracellular Signaling Peptides..., http://linkedlifedata.com/resource/pubmed/chemical/Myosins, http://linkedlifedata.com/resource/pubmed/chemical/Phosphoprotein Phosphatases, http://linkedlifedata.com/resource/pubmed/chemical/Phosphorylase a, http://linkedlifedata.com/resource/pubmed/chemical/Polyamines, http://linkedlifedata.com/resource/pubmed/chemical/Polylysine, http://linkedlifedata.com/resource/pubmed/chemical/Polymers, http://linkedlifedata.com/resource/pubmed/chemical/Proteins, http://linkedlifedata.com/resource/pubmed/chemical/polycations, http://linkedlifedata.com/resource/pubmed/chemical/protein phosphatase inhibitor-1, http://linkedlifedata.com/resource/pubmed/chemical/protein phosphatase inhibitor-2
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0037-9727
pubmed:author
pubmed:issnType
Print
pubmed:volume
180
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
488-96
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1985
pubmed:articleTitle
A new heat-stable regulatory factor is associated with aortic polycation-modulated (PCM)-phosphatase.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.