RLK/TXK: Proteins and Enzymes

RLK (resting lymphocyte kinase), also called TXK (T cell-expressed kinase) or PTK4, is a protein tyrosine kinase of the TEK family. It is expressed in T cells and some myeloid cells, especially in Th1 cells in inflammatory diseases such as rheumatoid arthritis and Behcet’s disease. Upon TCR stimulation, it translocates to the nucleus and induces IFN gamma production. An alternate start site creates two forms, a resident nuclear 55 kDa form and a larger (~58 kDa) cytoplasmic or plasma membrane-associated form.