Lj. Graham et al., Differential effects of Cbl and 70Z/3 Cbl on T cell receptor-induced phospholipase C gamma-1 activity, FEBS LETTER, 470(3), 2000, pp. 273-280
We demonstrate that the differential effects Cbl and oncogenic 70Z/3 Cbl ha
ve on Ca2+/Ras-sensitive NF-AT reporters is partially due to their opposing
ability to regulate phospholipase C gamma 1 (PLC gamma 1) activation as de
monstrated by analysis of the activation of an NF-AT reporter construct and
PLC gamma 1-mediated inositol phospholipid (PI) hydrolysis. Cbl overexpres
sion resulted in reduced T cell receptor-induced Pf hydrolysis, in the abse
nce of any effect on PLC gamma 1 tyrosine phosphorylation, In contrast, exp
ression of 70Z/3 Cbl led to an increase in basal and OKT3-induced PLC gamma
1 phosphorylation and PI hydrolysis, These data indicate that Cbl and 70Z/
3 Cbl differentially regulate PLC gamma 1 phosphorylation and activation, T
he implications of these data on the mechanism of Chi-mediated signaling re
gulation are discussed. (C) 2000 Federation of European Biochemical Societi
es.