Immunology
LAT is Important for Fc
RI Signaling
The linker protein LAT functions as a signaling network hub where several proteins bind and become activated. The importance of LAT in T cell-receptor signaling is well documented; however, the role of LAT in other immune cells has not been so intensively examined. Saitoh et al. show that LAT has an important function in Fc
RI signaling in mast cells. Mast cells derived from LAT-deficient mice are able to partially signal through Fc
RI cross-linking and can activate Syk and Vav; however, activation of SLP-76, of both isoforms of PLC-
, and of specific MAPK pathways was greatly reduced. In addition, Ca2+ mobilization, exocytotic degranulation, and the expression of several cytokines were impaired in LAT-deficient mast cells. These results suggest that LAT is important for proper signaling by Fc
RI and for physiological responses to antigens.
Saitoh, S., Arudchandran, R., Manetz, T.S., Zhang, W., Sommers, C.L., Love, P.E., Rivera, J., and Samelson, L.E. (2000) LAT is essential for Fc
RI-mediated mast cell activation. Immunity 12: 525-535. [Online Journal]