TRB

T cell receptors (TCRs) recognize foreign antigens which have been processed as small peptides and bound to major histocompatibility complex (MHC) molecules at the surface of antigen presenting cells (APC). Each TCR is a dimer consisting of one alpha and one beta chain or one delta and one gamma chain. In a single cell, the TCR loci are rearranged and expressed in the order delta, gamma, beta, and alpha. If both delta and gamma rearrangements produce functional chains, the cell expresses delta and gamma. If not, the cell proceeds to rearrange the beta and alpha loci. This region represents the germline organization of the T cell receptor beta locus. The beta locus includes V (variable), J (joining), diversity (D), and C (constant) segments. During T cell development, the beta chain is synthesized by a recombination event at the DNA level joining a D segment with a J segment; a V segment is then joined to the D-J gene. The C segment is later joined by splicing at the RNA level. Recombination of many different V segments with several J segments provides a wide range of antigen recognition. Additional diversity is attained by junctional diversity, resulting from the random additional of nucleotides by terminal deoxynucleotidyltransferase. Several V segments and one J segment of the beta locus are known to be incapable of encoding a protein and are considered pseudogenes. The beta locus also includes eight trypsinogen genes, three of which encode functional proteins and five of which are pseudogenes. Chromosomal abnormalities involving the T-cell receptor beta locus have been associated with T-cell lymphomas. [provided by RefSeq, Jul 2008]

T Cell Receptor Beta Locus

The beta chain of TRAV38-2DV8*01J31*01C*01/TRBV25-1*01J2S3*01C2*01 alpha-beta T cell receptor (TR) clonotype that displays pan-cancer cell recognition via the invariant MR1 molecule. On CD8-positive T cell clone MC.7.G5, likely recognizes tumor-specific or -associated metabolite(s) essential for cancer cell survival, triggering killing of many cancer cell types including lung, melanoma, leukemia, colon, breast, prostate, bone and ovarian cancer cells. Mediates cancer cell cytotoxicity in an HLA-independent manner. Has no reactivity to healthy cells even stressed or infected by bacteria (PubMed:31959982).
Antigen recognition 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 differentiation into effector/memory T cells (By similarity).

Biological Process detection of tumor cell Source:UniProtKB1 Publication
Biological Process T cell mediated cytotoxicity directed against tumor cell target Source:UniProtKB1 Publication

Cell membrane

Helical: 282-304
Cytoplasmic: 305-315