T. Matsuda et al., SOCS-1 can suppress CD3 zeta- and Syk-mediated NF-AT activation in a non-lymphoid cell line, FEBS LETTER, 472(2-3), 2000, pp. 235-240
To elucidate T cell antigen receptor (TCR) signaling leading to activation
nuclear factor of activated T cells (NF-AIT), we reconstituted TCR signalin
g to activate NF-AT in a non-lymphoid cell line, 293T, We demonstrated that
co-expression of CD8/zeta and Syk were neccesary for NF-AT activation in 2
93T, This NF-AT response was completely inhibited hy the addition of cyclos
porin A or FK506, but markedly enhanced by the additional expression of Tee
protein tyrosine kinase, We also show that the cytokine signaling suppress
or, suppressor of cytokine signaling 1, potently inhibited this response by
interacting with Syk and immunoreceptor tyrosine-based activation motifs i
n CD8/zeta, These results imply that this novel system may provide a useful
tool to delineate or identify the regulatory molecules for CD3 zeta/Syk-me
diated NF-AT activation. (C) 2000 Federation of European Biochemical Societ
ies.