PTK6

Protein-tyrosine kinase 6 ;
Breast tumor kinase ;
Tyrosine-protein kinase BRK ;

catalytic activity:ATP + a [protein]-L-tyrosine = ADP + a [protein]-L-tyrosine phosphate.,enzyme regulation:Activated enzyme seems to have greater access to its substrates.,function:Phosphorylates KHDRBS1, KHDRBS2, KHDRBS3 and STAP2/BKS. May function as an intracellular signal transducer in epithelial tissues. Overexpression in mammary cells leads to mitogenically sensitization to EGF, and results in a partially transformed phenotype. Its presence in the nucleus appears to be linked to suppression of tumor progression.,PTM:Autophosphorylated. The phosphorylation of Tyr-447 may lead to the autoinhibition of the enzyme.,similarity:Belongs to the protein kinase superfamily. Tyr protein kinase family. BRK/PTK6/SIK subfamily.,similarity:Contains 1 protein kinase domain.,similarity:Contains 1 SH2 domain.,similarity:Contains 1 SH3 domain.,subcellular location:Colocalizes with KHDRBS1, KHDRBS2 or KHDRBS3, within the nucleus. In secretory epithelial cells from prostate adenocarcinoma, nuclear localization is higher in low-grade and lower in high-grade regions of the tumors.,subunit:Interacts with GAP-A.p65 (By similarity). Interacts with KHDRBS1. Interacts with phosphorylated IRS4.,tissue specificity:Epithelia-specific. Very high level in colon and high levels in small intestine and prostate, and low levels in some fetal tissues. Expressed at low level in some breast tumors, but not in normal breast. Also found in melanocytes. Not expressed in heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas.,

protein amino acid phosphorylation, phosphorus metabolic process, phosphate metabolic process, phosphorylation,

Cytoplasm. Nucleus. Cell projection, ruffle. Membrane . Colocalizes with KHDRBS1, KHDRBS2 or KHDRBS3, within the nucleus. Nuclear localization in epithelial cells of normal prostate but cytoplasmic localization in cancer prostate.

Epithelia-specific. Very high level in colon and high levels in small intestine and prostate, and low levels in some fetal tissues. Not expressed in breast or ovarian tissue but expressed in high percentage of breast and ovarian cancers. Also overexpressed in some metastatic melanomas, lymphomas, colon cancers, squamous cell carcinomas and prostate cancers. Also found in melanocytes. Not expressed in heart, brain, placenta, lung, liver, skeletal muscle, kidney and pancreas. Isoform 2 is present in prostate epithelial cell lines derived from normal prostate and prostate adenocarcinomas, as well as in a variety of cell lines.