T cell receptor alpha variable 23/delta variable 6
1_MDKIL 6_ GASFL 11_ VLWLQ 16_ LCWVS 21_ GQQKE 26_ KSDQQ 31_ QVKQS 36_ PQSLI 41_ VQKGG 46_ ISIIN 51_ CAYEN 56_ TAFDY 61_ FPWYQ 66_ QFPGK 71_ GPALL 76_ IAIRP 81_ DVSEK 86_ KEGRF 91_ TISFN 96_ KSAKQ 101_ FSSHI 106_ MDSQP 111_ GDSAT 116_YFCAA
1: V region of the variable domain of T cell receptor (TR) alpha chain that participates in the antigen recognition (PubMed:24600447). Alpha-beta T cell receptors are antigen specific receptors which are essential to the immune response and are present on the cell surface of T lymphocytes. Recognize peptide-major histocompatibility (MH) (pMH) complexes that are displayed by antigen presenting cells (APC), a prerequisite for efficient T cell adaptive immunity against pathogens (PubMed:25493333). Binding of alpha-beta TR to 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 enabling the recruitment of ZAP70. In turn ZAP70 phosphorylates LAT, which recruits numerous signaling molecules to form the LAT signalosome. The LAT signalosome propagates signal branching to three major signaling pathways, the calcium, the mitogen-activated protein kinase (MAPK) kinase and the nuclear factor NF-kappa-B (NF-kB) pathways, leading to the mobilization of transcription factors that are critical for gene expression and essential for T cell growth and differentiation (PubMed:23524462). The T cell repertoire is generated in the thymus, by V-(D)-J rearrangement. This repertoire is then shaped by intrathymic selection events to generate a peripheral T cell pool of self-MH restricted, non-autoaggressive T cells. Post-thymic interaction of alpha-beta TR with the pMH complexes shapes TR structural and functional avidity (PubMed:15040585)