T cell receptor delta constant
1_SQPHT 6_ KPSVF 11_ VMKNG 16_ TNVAC 21_ LVKEF 26_ YPKDI 31_ RINLV 36_ SSKKI 41_ TEFDP 46_ AIVIS 51_ PSGKY 56_ NAVKL 61_ GKYED 66_ SNSVT 71_ CSVQH 76_ DNKTV 81_ HSTDF 86_ EVKTD 91_ STDHV 96_ KPKET 101_ ENTKQ 106_ PSKSC 111_ HKPKA 116_ IVHTE 121_ KVNMM 126_ SLTVL 131_ GLRML 136_ FAKTV 141_ AVNFL 146_LTAKL
1: Constant region of T cell receptor (TR) delta chain that participates in the antigen recognition (PubMed:24600447). Gamma-delta TRs recognize a variety of self and foreign non-peptide antigens frequently expressed at the epithelial boundaries between the host and external environment, including endogenous lipids presented by MH-like protein CD1D and phosphoantigens presented by butyrophilin-like molecule BTN3A1. Upon antigen recognition induces rapid, innate-like immune responses involved in pathogen clearance and tissue repair (PubMed:23348415, PubMed:28920588). Binding of gamma-delta TR complex to antigen triggers phosphorylation of immunoreceptor tyrosine-based activation motifs (ITAMs) in the CD3 chains by the LCK and FYN kinases, allowing the recruitment, phosphorylation, and activation of ZAP70 that facilitates phosphorylation of the scaffolding proteins LCP2 and LAT. This lead to the formation of a supramolecular signalosome that recruits the phospholipase PLCG1, resulting in calcium mobilization and ERK activation, ultimately leading to T cell expansion and differentiation into effector cells (PubMed:25674089). Gamma-delta TRs are produced through somatic rearrangement of a limited repertoire of variable (V), diversity (D), and joining (J) genes. The potential diversity of gamma-delta TRs is conferred by the unique ability to rearrange (D) genes in tandem and to utilize all three reading frames. The combinatorial diversity is considerably increased by the sequence exonuclease trimming and random nucleotide (N) region additions which occur during the V-(D)-J rearrangements (PubMed:24387714)