Heterodimeric antigen receptors present on the surface of T-cells. Two T-cell antigen receptors have been identified, consisting of heterodimeric 40-55 kD Ig-like alpha/beta or gamma/delta integral membrane glycoproteins. Genes for TCR alpha, beta, gamma, and delta subunits are assembled during T-cell development by somatic rearrangement of germline gene segments, resembling B-cell Ig genes in their mechanisms of diversity generation and activation of expression. Alpha/beta heterodimers are found on helper and cytotoxic T-cells and are specific for antigenic peptides presented by MHC gene products. T-cells expressing gamma/delta heterodimers directly recognize proteins and non-proteinacious phospho-ligands. T-cell receptors are non-covalently associated with CD3, forming the TCR-CD3 complex. TCRs activate MAPKs and JNK1 through the CD3 antigens, the adaptor protein LAT, and tyrosine kinases LCK and ZAP70. (from OMIM and NCI)

(t cell receptor) Immunoglobulin like receptor associated with CD3 marker on T lymphocytes which binds specific antigen and thereby participates in T cell activation; recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen receptor structure, composed of either alpha-beta or gamma-delta chains.

(receptors, antigen, t-cell) Molecules on the surface of T-lymphocytes that recognize and combine with antigens. The receptors are non-covalently associated with a complex of several polypeptides collectively called CD3 antigens (CD3 COMPLEX). Recognition of foreign antigen and the major histocompatibility complex is accomplished by a single heterodimeric antigen-receptor structure, composed of either alpha-beta (RECEPTORS, ANTIGEN, T-CELL, ALPHA-BETA) or gamma-delta (RECEPTORS, ANTIGEN, T-CELL, GAMMA-DELTA) chains.