Linked Life Data

15184383

Source:http://linkedlifedata.com/resource/pubmed/id/15184383

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
36
pubmed:dateCreated
2004-8-30
pubmed:abstractText
Tyrosine phosphorylation of phospholipase Cgamma2 (PLCgamma2) is a crucial activation switch that initiates and maintains intracellular calcium mobilization in response to B cell antigen receptor (BCR) engagement. Although members from three distinct families of non-receptor tyrosine kinases can phosphorylate PLCgamma in vitro, the specific kinase(s) controlling BCR-dependent PLCgamma activation in vivo remains unknown. Bruton's tyrosine kinase (Btk)-deficient human B cells exhibit diminished inositol 1,4,5-trisphosphate production and calcium signaling despite a normal inducible level of total PLCgamma2 tyrosine phosphorylation. This suggested that Btk might modify a critical subset of residues essential for PLCgamma2 activity. To evaluate this hypothesis, we generated site-specific phosphotyrosine antibodies recognizing four putative regulatory residues within PLCgamma2. Whereas all four sites were rapidly modified in response to BCR engagement in normal B cells, Btk-deficient B cells exhibited a marked reduction in phosphorylation of the Src homology 2 (SH2)-SH3 linker region sites, Tyr(753) and Tyr(759). Phosphorylation of both sites was restored by expression of Tec, but not Syk, family kinases. In contrast, phosphorylation of the PLCgamma2 carboxyl-terminal sites, Tyr(1197) and Tyr(1217), was unaffected by the absence of functional Btk. Together, these data support a model whereby Btk/Tec kinases control sustained calcium signaling via site-specific phosphorylation of key residues within the PLCgamma2 SH2-SH3 linker.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
279
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
37651-61
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Tec kinases mediate sustained calcium influx via site-specific tyrosine phosphorylation of the phospholipase Cgamma Src homology 2-Src homology 3 linker.
pubmed:affiliation
Molecular Biology Institute and Department of Microbiology and Immunology, UCLA, Los Angeles, California 90095, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.