Linked Life Data

2493392

Source:http://linkedlifedata.com/resource/pubmed/id/2493392

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1989-4-7
pubmed:abstractText
The antiserum AS7 can specifically immunoprecipitate alpha-Gi from membrane extracts as well as from a mixture of purified alpha-Gi and alpha-Go as ascertained using [32P]ADP-ribosylated G-proteins. Using this antiserum to immunoprecipitate alpha-Gi from hepatocytes labelled with 32P it was evident that alpha-Gi was phosphorylated under basal (resting) conditions. Challenge of hepatocytes with the tumour promoting phorbol ester TPA, however, elicited a marked enhancement of the phosphorylation state of alpha-Gi. This was accompanied by the loss of inhibitory effect of Gi on adenylate cyclase, as judged by the inability of low concentrations of p[NH]ppG to inhibit forskolin-stimulated adenylate cyclase activity. Such actions were mimicked by treatment of hepatocytes with either glucagon or TH-glucagon, an analogue of glucagon which is incapable of activating adenylate cyclase and elevating intracellular cyclic AMP concentrations. Pre-treatment of hepatocytes with either glucagon, TPA or insulin did not affect the ability of pertussis toxin to cause the NAD+-dependent, [32P]ADP-ribosylation of alpha-Gi in membrane fractions isolated from such pre-treated hepatocytes. We suggest that protein kinase C can elicit the phosphorylation and functional inactivation of alpha-Gi in intact hepatocytes. As pertussis toxin only causes the ADP-ribosylation of the holomeric form of Gi, it may be that phosphorylation leaves alpha-Gi in its holomeric state.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-5793
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
243
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
77-82
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1989
pubmed:articleTitle
Treatment of intact hepatocytes with either the phorbol ester TPA or glucagon elicits the phosphorylation and functional inactivation of the inhibitory guanine nucleotide regulatory protein Gi.
pubmed:affiliation
Institute of Biochemistry, University of Glasgow, Scotland.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't