Unc119, a Novel Activator of Lck/Fyn, Is Essential for T Cell Activation
Open Access
- 26 January 2004
- journal article
- Published by Rockefeller University Press in The Journal of Experimental Medicine
- Vol. 199 (3), 369-379
- https://doi.org/10.1084/jem.20030589
Abstract
The first step in T cell receptor for antigen (TCR) signaling is the activation of the receptor-bound Src kinases, Lck and Fyn. The exact mechanism of this process is unknown. Here, we report that the novel Src homology (SH) 3/SH2 ligand–Uncoordinated 119 (Unc119) associates with CD3 and CD4, and activates Lck and Fyn. Unc119 overexpression increases Lck/Fyn activity in T cells. In Unc119-deficient T cells, Lck/Fyn activity is dramatically reduced with concomitant decrease in interleukin 2 production and cellular proliferation. Reconstitution of cells with Unc119 reverses the signaling and functional outcome. Thus, Unc119 is a receptor-associated activator of Src-type kinases. It provides a novel mechanism of signal generation in the TCR complex.This publication has 19 references indexed in Scilit:
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