T cell receptor alpha joining 3 (TRAJ3)

J area of the variable domain of T cell receptor (TR) alpha chain that engages in the antigen recognition (PubMed:24600447). Alpha-beta T cell receptors are antigen specific receptors that are important to the immune response and are present on the cell surface of T lymphocytes.

Recognize peptide-major histocompatibility (MH) (pMH) complexes that are exhibited by antigen presenting cells (APC), a prerequisite for efficient T cell adaptive immunity against pathogens (PubMed:25493333). Binding of alpha-beta TR into pMH complex initiates TR-CD3 clustering on the cell surface and intracellular activation of LCK that phosphorylates the ITAM motifs of CD3G, CD3D, CD3E and CD247 allowing the recruitment of ZAP70.