TXK 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 lead 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. With PARP1 and EEF1A1, TXK forms a complex that acts as a T-helper 1 (Th1) cell-specific transcription factor and binds the promoter of IFNG to directly regulate its transcription, and is thus involved importantly in Th1 cytokine production. Phosphorylates both PARP1 and EEF1A1. 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. Belongs to the protein kinase superfamily. Tyr protein kinase family. TEC subfamily. Expressed in T-cells and some myeloid cell lines. Expressed in Th1/Th0 cells with IFN-gamma-producing potential. Note: This description may include information from UniProtKB.
Protein type: EC; Kinase, protein; Protein kinase, TK; Protein kinase, tyrosine (non-receptor); TK group; Tec family
Chromosomal Location of mouse Ortholog: 5 C3.2|5 38.44 cM
Cellular Component:  cytoplasm; membrane; nucleus; plasma membrane
Molecular Function:  ATP binding; DNA binding; DNA-binding transcription activator activity, RNA polymerase II-specific; kinase activity; non-membrane spanning protein tyrosine kinase activity; nucleotide binding; protein kinase activity; protein tyrosine kinase activity; RNA polymerase II proximal promoter sequence-specific DNA binding; RNA polymerase II regulatory region DNA binding; transferase activity
Biological Process:  activation of phospholipase C activity; adaptive immune response; cytokine production; immune system process; interferon-gamma production; interleukin-4 production; NK T cell differentiation; peptidyl-tyrosine autophosphorylation; phosphorylation; positive regulation of interferon-gamma production; positive regulation of interferon-gamma-mediated signaling pathway; positive regulation of transcription by RNA polymerase II; protein autophosphorylation; protein phosphorylation; regulation of transcription by RNA polymerase II; T cell receptor signaling pathway
Reference #:  P42682 (UniProtKB)
Alt. Names/Synonyms: A130089B16Rik; Btk; Btkl; PTK; PTK-RL-18; PTK4; Resting lymphocyte kinase; Rlk; Txk; TXK tyrosine kinase; Tyrosine-protein kinase TXK
Gene Symbols: Txk
Molecular weight: 61,108 Da
Basal Isoelectric point: 8.68  Predict pI for various phosphorylation states
CST Pathways:  Tyrosine Kinases & Substrates
Select Structure to View Below


Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  Reactome  |  BioGPS  |  KinBase  |  Pfam  |  ENZYME  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene  |  Ensembl Gene