ITK Protein, Human (Active, 269a.a, sf9, His, GST)

ITK protein, a crucial tyrosine kinase, plays an indispensable role in the regulation of the adaptive immune response by orchestrating the development, function, and differentiation of conventional T-cells and nonconventional NKT-cells. Upon activation of the T-cell receptor (TCR) by antigen-presenting cells (APC), a phosphorylation cascade ensues, leading to the recruitment of ITK to the cell membrane in close proximity to the stimulated TCR receptor. Subsequently, ITK undergoes phosphorylation by LCK, resulting in its autophosphorylation and full activation. Once activated, ITK phosphorylates PLCG1, activating this lipase and initiating the cleavage of its substrates. This process triggers the release of calcium from the endoplasmic reticulum into the cytoplasm, facilitating the translocation of the nuclear activator of activated T-cells (NFAT) into the nucleus for transcriptional regulation. Additionally, ITK phosphorylates essential adapter proteins like the linker for activation of T-cells/LAT protein and LCP2, recruiting a myriad of signaling molecules, including VAV1, ultimately leading to lymphokine production, T-cell proliferation, and differentiation. ITK is crucial for TCR-mediated calcium response in gamma-delta T-cells and may play a role in modulating the transcriptomic signature in the Vgamma2-positive subset of immature gamma-delta T-cells. Furthermore, ITK phosphorylates TBX21 at 'Tyr-530,' mediating its interaction with GATA3. This multifaceted involvement underscores the pivotal role of ITK in shaping diverse facets of the adaptive immune response.