Reactome: A Curated Pathway Database

TCR signaling (R-HSA-202403)

Species Homo sapiens


The TCR is a multisubunit complex that consists of clonotypic alpha/beta chains noncovalently associated with the invariant CD3 delta/epsilon/gamma and TCR zeta chains. T cell activation by antigen presenting cells (APCs) results in the activation of protein tyrosine kinases (PTKs) that associate with CD3 and TCR zeta subunits and the co-receptor CD4. Members of the Src kinases (Lck), Syk kinases (ZAP-70), Tec (Itk) and Csk families of nonreceptor PTKs play a crucial role in T cell activation. Activation of PTKs following TCR engagement results in the recruitment and tyrosine phosphorylation of enzymes such as phospholipase C gamma1 and Vav as well as critical adaptor proteins such as LAT, SLP-76 and Gads. These proximal activation leads to reorganization of the cytoskeleton as well as transcription activation of multiple genes leading to T lymphocyte proliferation, differentiation and/or effector function.

Locations in the PathwayBrowser
Additional Information
GO Biological Process T cell receptor signaling pathway (0050852)
Literature References
pubMedId Title Journal Year
9989491 Adaptors and molecular scaffolds in immune cell signaling Cell 1999
10375551 T cell antigen-receptor signal transduction Curr Opin Immunol 1999
12876557 Unifying concepts in CD28, ICOS and CTLA4 co-receptor signalling Nat Rev Immunol 2003