Association of the tyrosine kinase LCK with phospholipase C-gamma 1 after stimulation of the T cell antigen receptor.
Stimulation of the T cell antigen receptor (TCR) activates a protein tyrosine kinase and leads to the tyrosine phosphorylation of phosphoinositide-specific phospholipase C-gamma 1 (PLC gamma 1). The molecular interactions involved in this phosphorylation are not known. After stimulation of the TCR on Jurkat T cells, tyrosine-phosphorylated proteins of 36, 38, 58, and 63 kD coprecipitate with PLC gamma 1. An identical pattern of proteins precipitate with TrpE fusion proteins that contain the Src homology (SH) 2 domains of PLC gamma 1, indicating that these regions of PLC gamma 1 are responsible for binding. TCR stimulation leads to an association between the SH2 domains of PLC gamma 1 and a protein tyrosine kinase, which, by peptide mapping, is identical to p56lck. These studies establish that p56lck associates with PLC gamma 1 as a result of TCR stimulation of Jurkat cells, suggesting that p56lck plays a central role in coupling the TCR to the activation of PLC gamma 1.
Weber
J R
JR
Department of Medicine, University of California, San Francisco.
Bell
G M
GM
Han
M Y
MY
Pawson
T
T
Imboden
J B
JB
D002460:Cell Line; D006801:Humans; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D010449:Peptide Mapping; D010766:Phosphorylation; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D013601:T-Lymphocytes / Q000201:enzymology / Q000378:metabolism*; D010738:Type C Phospholipases / Q000378:metabolism*; D014443:Tyrosine / Q000378:metabolism
D011948:Receptors, Antigen, T-Cell; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D019860:Lymphocyte Specific Protein Tyrosine Kinase p56(lck); D010738:Type C Phospholipases