TXK

TXK (TXK Tyrosine Kinase) is a Protein Coding gene. Diseases related to TXK include Behcet Syndrome and Leukoencephalopathy With Vanishing White Matter. Among its related pathways are Akt Signaling and Innate Immune System. Gene Ontology (GO) annotations related to TXK include transferase activity, transferring phosphorus-containing groups and protein tyrosine kinase activity. An important paralog of TXK is TEC.

Full Name

TXK tyrosine kinase

Function

Non-receptor tyrosine kinase that plays a redundant role with ITK in regulation of the adaptive immune response. Regulates the development, function and differentiation of conventional T-cells and nonconventional NKT-cells. When antigen presenting cells (APC) activate T-cell receptor (TCR), a series of phosphorylation leads to the recruitment of TXK to the cell membrane, where it is phosphorylated at Tyr-420. Phosphorylation leads to TXK full activation. Contributes also to signaling from many receptors and participates in multiple downstream pathways, including regulation of the actin cytoskeleton. Like ITK, can phosphorylate PLCG1, leading to its localization in lipid rafts and activation, followed by subsequent cleavage of its substrates. In turn, the endoplasmic reticulum releases calcium in the cytoplasm and the nuclear activator of activated T-cells (NFAT) translocates into the nucleus to perform its transcriptional duty. Plays a role in the positive regulation of IFNG transcription in T-helper 1 cells as part of an IFNG promoter-binding complex with PARP1 and EEF1A1 (PubMed:11859127, PubMed:17177976).
Within the complex, phosphorylates both PARP1 and EEF1A1 (PubMed:17177976).
Phosphorylates also key sites in LCP2 leading to the up-regulation of Th1 preferred cytokine IL-2. Phosphorylates 'Tyr-201' of CTLA4 which leads to the association of PI-3 kinase with the CTLA4 receptor.

Biological Process

Biological Process activation of phospholipase C activity Source:UniProtKB
Biological Process adaptive immune response Source:UniProtKB
Biological Process integrin-mediated signaling pathway Source:GO_Central1 Publication
Biological Process positive regulation of cytokine production Source:UniProtKB
Biological Process positive regulation of transcription by RNA polymerase II Source:NTNU_SB1 Publication
Biological Process positive regulation of type II interferon production Source:UniProtKB2 Publications
Biological Process positive regulation of type II interferon-mediated signaling pathway Source:UniProtKB1 Publication
Biological Process protein autophosphorylation Source:UniProtKB2 Publications
Biological Process protein phosphorylation Source:UniProtKB1 Publication
Biological Process regulation of gene expression Source:GO_Central1 Publication
Biological Process regulation of platelet activation Source:GO_Central1 Publication
Biological Process T cell receptor signaling pathway Source:UniProtKB
Biological Process tissue regeneration Source:GO_Central1 Publication

Cellular Location

Cytoplasm
Nucleus
Cell membrane
Localizes in the vicinity of cell surface receptors in the plasma membrane after receptor stimulation. Translocates into the nucleus and enhances IFN-gamma gene transcription in T-cells.

PTM

Phosphorylated at Tyr-420 by FYN. Autophosphorylation at Tyr-91 is critical for the activation of TXK, leading to the up-regulation of IFN-gamma gene transcription.
The cysteine string at the N-terminus is palmitoylated and required for the proper subcellular location.