UNIPROT #

P43403

PROTEIN NAME

ZAP70

SYNONYMS

70 kDa zeta associated protein antibody; 70 kDa zeta-associated protein antibody; EC 2.7.10.2 antibody; FLJ17670 antibody; FLJ17679 antibody; Selective T cell defect antibody; SRK antibody; STD antibody; Syk related tyrosine kinase antibody; Syk-related tyrosine kinase antibody; Truncated ZAP kinase antibody; Tyrosine protein kinase ZAP70 antibody; Tyrosine-protein kinase ZAP-70 antibody; TZK antibody; ZAP 70 antibody; ZAP70 antibody; ZAP70_HUMAN antibody; Zeta chain associated protein kinase 70kD antibody; Zeta chain associated protein kinase 70kDa antibody; Zeta chain associated protein kinase 70kDa isoform 1 antibody; Zeta chain associated protein kinase 70kDa isoform 2 antibody; Zeta chain of T cell receptor associated protein kinase 70 antibody; Zeta chain TCR associated protein kinase 70kD antibody; Zeta chain TCR associated protein kinase 70kDa antibody

SEQUENCE SIMILARITIES

Belongs to the protein kinase superfamily. Tyr protein kinase family. SYK/ZAP-70 subfamily.

TISSUE SPECIFICITY

Expressed in T- and natural killer cells. Also present in early thymocytes and pro/pre B-cells.

POST-TRANSLATIONAL MODIFICATION

Phosphorylated on tyrosine residues upon T-cell antigen receptor (TCR) stimulation. Phosphorylation of Tyr-315 and Tyr-319 are essential for ZAP70 positive function on T-lymphocyte activation whereas Tyr-292 has a negative regulatory role. Within the C-terminal kinase domain, Tyr-492 and Tyr-493 are phosphorylated after TCR induction, Tyr-492 playing a negative regulatory role and Tyr-493 a positive. Tyr-493 is dephosphorylated by PTN22.; Ubiquitinated in response to T cell activation. Deubiquitinated by OTUD7B.

SUBCELLULAR LOCATION

Cytoplasm. Cell membrane.

FUNCTION

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 α and β chains, the CD3 γ, δ and e chains and a ζ-containing homodimer or heterodimer. The disulfide-linked Ti α-β heterodimer is responsible for antigen recognition, but the short 5 amino acid cytoplasmic domains of Ti α and β are unlikely to be sufficient to couple to intracellular signaling pathways. In contrast, the structured features of the CD3 and ζ subunits suggest a role in signal transduction. Of these, the ζ 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.