| Primary Identifier | IPR042785 | Type | Domain |
| Short Name | ITK_PTKc |
| description | PTKs catalyse the transfer of the gamma-phosphoryl group from ATP to tyrosine (tyr) residues in protein substrates. Itk, also known as Tsk or Emt, is a member of the Tec-like subfamily of proteins, which are cytoplasmic (or nonreceptor) PTKs with similarity to Src kinases in that they contain Src homology protein interaction domains (SH3, SH2) N-terminal to the catalytic tyr kinase domain. Unlike Src kinases, most Tec subfamily members except Rlk also contain an N-terminal pleckstrin homology (PH) domain, which binds the products of PI3K and allows membrane recruitment and activation. In addition, Itk contains the Tec homology (TH) domain containing one proline-rich region and a zinc-binding region [, ].Itk is expressed in T-cells and mast cells, and is important in their development and differentiation []. Of the three Tec kinases expressed in T-cells, Itk plays the predominant role in T-cell receptor (TCR) signalling. It is activated by phosphorylation upon TCR crosslinking and is involved in the pathway resulting in phospholipase C-gamma1 activation and actin polymerization []. It also plays a role in the downstream signalling of the T-cell costimulatory receptor CD28, the T-cell surface receptor CD2, and the chemokine receptor CXCR4 [, ]. In addition, Itk is crucial for the development of T-helper(Th)2 effector responses []. |
