Tyrosine phosphorylation of Grb2-associated proteins correlates with phospholipase C gamma 1 activation in T cells.
Mol Cell Biol
; 16(6): 2823-9, 1996 Jun.
Article
em En
| MEDLINE
| ID: mdl-8649391
ABSTRACT
Ligation of the T-cell antigen receptor (TCR) results in the rapid activation of several protein tyrosine kinases, with the subsequent phosphorylation of numerous cellular proteins. We investigated the requirement for tyrosine phosphorylation of proteins which bind the Grb2 SH2 domain in TCR-mediated signal transduction by transfecting the Jurkat T-cell line with a cDNA encoding a chimeric protein designed to dephosphorylate these molecules. Stimulation of the TCR on cells expressing this engineered enzyme fails to result in sustained tyrosine phosphorylation of a 36-kDa protein likely to be the recently cloned pp36/Lnk. Interestingly, TCR ligation of the transfected cells also fails to induce soluble inositol phosphate production and intracellular calcium mobilization, although receptor-mediated tyrosine phosphorylation of phospholipase C gamma 1 still occurs. TCR-mediated Ras and mitogen-activated protein kinase activation remain intact in cells expressing the engineered phosphatase. These data demonstrate that tyrosine phosphorylation of a protein(s) which binds the SH2 domain of Grb2 correlates with phospholipase C gamma 1 activation and suggest that such a phosphoprotein(s) plays a critical role in coupling the TCR with the phosphatidylinositol second-messenger pathway.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Fosfolipases Tipo C
/
Tirosina
/
Linfócitos T
/
Proteínas
/
Proteínas Adaptadoras de Transdução de Sinal
/
Isoenzimas
Tipo de estudo:
Risk_factors_studies
Limite:
Humans
Idioma:
En
Revista:
Mol Cell Biol
Ano de publicação:
1996
Tipo de documento:
Article
País de afiliação:
Estados Unidos