Linked Life Data

6850989

Source:http://linkedlifedata.com/resource/pubmed/id/6850989

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1983-7-15
pubmed:abstractText
Most chemical carcinogens require activation by polysubstrate monooxygenase. The phosphorylation of essential components of this cytochrome P-450 monooxygenase system, isolated from rabbit liver microsomes, cytochrome P-450 (LM2) and cytochrome reductase, was tested using two different protein kinases. One of the kinases, a cyclic AMP-independent phosvitin kinase (kinase P), was inactive in all systems tested. However, the catalytic subunit of a cyclic AMP-dependent protein kinase (kinase C) catalyzed phosphoryl group transfer to both proteins, but to different extents. Cytochrome P-450 was phosphorylated when added as sole component and also when in the presence of P-450 reductase and phosphatidylcholine. In contrast, the weak phosphorylation of P-450 reductase was reduced considerably in a complete reconstituted system containing P-450 and phosphatidylcholine. The inclusion of kinase P did not alter these results which excludes the possibility that these kinases participate in a sequential phosphorylation mechanism. The monooxygenase constituents themselves were without kinase activity. When hepatic microsomes were isolated in presence of the phosphatase inhibitor sodium fluoride no significant change in monooxygenase (7-ethoxycoumarin O-deethylation) activity was observed, whilst after preincubation with either acid or alkaline phosphatase a significant reduction in monooxygenase activity was measured. Thus, cytochrome P-450 (LM2) is phosphorylatable by protein kinase C and the catalytic activity of polysubstrate monooxygenase decreases after preincubation of microsomes with phosphatases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0143-3334
pubmed:author
pubmed:issnType
Print
pubmed:volume
4
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
573-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Phosphorylation of cytochrome-P-450-dependent monooxygenase components.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't