Linked Life Data

7511643

Source:http://linkedlifedata.com/resource/pubmed/id/7511643

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1994-4-29
pubmed:abstractText
Cross-linking of the Ag receptor (AgR) induces intracellular signaling events in B cells, such as p21ras activation, that lead to their proliferation and differentiation. This event is accompanied by the tyrosine phosphorylation of the p21ras-associated GTPase-activating protein p120 ras.GAP, raising the possibility that AgR-stimulated p21ras activity is regulated by protein tyrosine kinases (PTKs) and protein tyrosine phosphatases (PTPases) in B cells. To test this possibility, we examined the effects of PTK and PTPase inhibitors on protein tyrosine phosphorylation and p21ras activation induced by AgR cross-linking in TNP-specific TA3 7.9 murine B lymphoma cells. Although AgR-induced protein tyrosine phosphorylation was inhibited by the PTK inhibitors genistein and herbimycin A, it was enhanced by exposure to the PTPase inhibitor phenylarsine oxide (PAO). Cross-linking of the AgR by Ag or F(ab')2 anti-IgM induced a rapid (within 5 min) two- to threefold increase in p21ras activation in 7.9 B cells. Interestingly, a second peak of p21ras activation was evident at approximately 40 min after stimulation. Genistein and herbimycin A and PAO each blocked AgR-stimulated p21ras activation. Similarly, Ag-induced p21ras activation was inhibited by pretreatment of 7.9 B cells with an anti-CD45 mAb (detects the 220-kDa B cell isoform of CD45). Moreover, p21ras activation was induced by Ag and F(ab')2 anti-IgM in CD45+ but not CD45- J558L microns 3 B cells. These data indicate that p21ras activation induced by AgR cross-linking in B cells is regulated by both PTK and CD45 PTPase activities.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0022-1767
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
152
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3306-16
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Tyrosine kinase and CD45 tyrosine phosphatase activity mediate p21ras activation in B cells stimulated through the antigen receptor.
pubmed:affiliation
Banting and Best Department of Medical Research, University of Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't