PTK6

PTK6 ;
BRK ;
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.