ZAP-70 Antibody (M-20): sc-1526

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The activation of T lymphocytes by antigens is mediated by the T cell receptor (TCR) which is a multisubunit complex assembled from at least six different genes. The TCR subunits include the Ti å and ß chains, the CD3 ©, ∂ and e chains and a Ω-containing homodimer or heterodimer. The disulfide-linked Ti å-ß heterodimer is responsible for antigen recognition, but the short 5 amino acid cytoplasmic domains of Ti å and ß are unlikely to be sufficient to couple to intracellular signaling pathways. In contrast, the structured features of the CD3 and Ω subunits suggest a role in signal transduction. Of these, the Ω chain, which is expressed as either a homodimer or heterodimer, has a short extracellular domain of only 9 amino acids, but a larger 113 amino acid cytoplasmic domain. A tyrosine phosphoprotein, ZAP-70, has been identified that associates with z and undergoes tyrosine phosphorylation following TCR stimulation.