Linked Life Data

9606022

Source:http://linkedlifedata.com/resource/pubmed/id/9606022

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-7-24
pubmed:abstractText
We investigated the effects of the receptor-coupled protein tyrosine kinase (RTK) v-Fms on the membrane current properties of NIH3T3 mouse fibroblasts. We found that v-Fms, the oncogenic variant of the macrophage colony-stimulating factor receptor c-Fms, activates a K+ current that is absent in control cells. The activation of the K+ current was Ca2+-dependent, voltage-independent, and was completely blocked by the K+ channel blockers charybdotoxin, margatoxin and iberiotoxin with IC50 values of 3 nM, 18 nM and 76 nM, respectively. To identify signalling components that mediate the activation of this K+ current, NIH3T3 cells that express different mutants of the wild-type v-Fms receptor were examined. Mutation of the binding site for the Ras-GTPase-activating protein led to a complete abolishment of the K+ current. A reduction of 76% and 63%, respectively, was observed upon mutation of either of the two binding sites for the growth factor receptor binding protein 2. Mutation of the ATP binding lobe, which disrupts the protein tyrosine kinase activity of v-Fms, led to a 55% reduction of the K+ current. Treatment of wild-type v-Fms cells with Clostiridium sordellii lethal toxin or a farnesyl protein transferase inhibitor, both known to inhibit the biological function of Ras, reduced the K+ current amplitude to 17% and 6% of the control value, respectively. This is the first report showing that an oncogenic RTK can modulate K+ channel activity. Our results indicate that this effect is dependent on the binding of certain Ras-regulating proteins to the v-Fms receptor and is not abolished by disruption of its intrinsic protein tyrosine kinase activity. Furthermore, our data suggest that Ras plays a key role for K+ channel activation by the oncogenic RTK v-Fms.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
357
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
378-84
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Activation of a Ca2+-dependent K+ current by the oncogenic receptor protein tyrosine kinase v-Fms in mouse fibroblasts.
pubmed:affiliation
Rudolf-Buchheim-Institut für Pharmakologie, Justus-Liebig-Universität Giessen, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't