LAT Background Information
LAT (linker of activation of T cells), is an integral membrane protein which links the proximal and distal portions of the TCR signaling pathway. LAT is atransmembrane protein that becomes rapidly tyrosine-phosphorylated after TCR engagement. Phosphorylation of LAT creates binding sites for the Src homology 2 (SH2) domains of other proteins, including PLC-gamma1, Grb2, Gads, Grap, 3BP2, and Shb, and indirectly binds SOS, c-Cbl, Vav, SLP-76, and Itk. T-cell-receptor-mediated LAT phosphorylation is critical for the membrane recruitment of signalling complexes required for T-cell activation. Tyr 191 and Tyr 171 phosphorylation are required for T-cell activation. Tyr 171 and Tyr 191 phosphorylation is also necessary for Grb2 and Gads binding, and are necessary and sufficient to achieve a Ca(2+) flux following TCR stimulation.
