[Term] id: PR:000001018 name: CD3 subunit with immunoglobulin domain def: "A protein that has a core domain composition consisting of an extracellular N-terminal domain that adopts an immunoglobulin fold, a transmembrane domain, and an intracellular C-terminal domain with a single copy of the Immunoreceptor tyrosine-based activation motif (Pfam:PF02189) (ITAM). It constitutes the invariant subunit of the T cell antigen receptor (TCR). TCR is a surface receptor on T cells responsible for recognizing MHC-restricted antigens and initiating the cellular immune response." [PMID:16473826, PMID:1724736] comment: Category=family. synonym: "CD3 subunit with Ig-like domain" EXACT [] xref: PIRSF:PIRSF001993 is_a: PR:000000001 ! protein