STK11

Serine/threonine-protein kinase STK11 ;
Liver kinase B1 ;
LKB1 ;
hLKB1 ;
Renal carcinoma antigen NY-REN-19 ;

catalytic activity:ATP + a protein = ADP + a phosphoprotein. ,cofactor:Magnesium or manganese. ,disease:Defects in STK11 are a cause of Peutz-Jeghers syndrome (PJS) [MIM:175200]. PJS is a rare hereditary disease in which there is predisposition to benign and malignant tumors of many organ systems. PJS is an autosomal dominant disorder characterized by melanocytic macules of the lips , multiple gastrointestinal hamartomatous polyps and an increased risk for various neoplasms , including gastrointestinal cancer. ,disease:Defects in STK11 have been associated with testicular tumors [MIM:273300]. It includes germ cell tumor (GCT) or testicular germ cell tumor (TGCT) . ,enzyme regulation:Activated by binding of a complex consisting of CAB39 and STRAD or CAB39 and ALS2CR2. ,function:Essential role in G1 cell cycle arrest. Phosphorylates and activates members of the AMPK-related subfamily of protein kinases. Tumor suppressor. ,online information:PJS entry ,PTM:Phosphorylated by a cAMP-dependent protein kinase. ,similarity:Belongs to the protein kinase superfamily. ,similarity:Belongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. LKB1 subfamily. ,similarity:Contains 1 protein kinase domain. ,subcellular location:Relocates to the cytoplasm when bound to CAB39 and STRAD or CAB39 and ALS2CR2. ,subunit:Found in a ternary complex composed of SMAD4 , STK11 and STK11IP. Interacts with SMAD4 and STK11IP. ,tissue specificity:Ubiquitously expressed. Strongest expression in testis and fetal liver. ,

protein amino acid phosphorylation , phosphorus metabolic process , phosphate metabolic process , cell cycle , cell cycle arrest , negative regulation of cell proliferation , regulation of cellular ketone metabolic process , phosphorylation ,regulation of lipid metabolic process , regulation of fatty acid metabolic process , cell cycle process , regulation of cell proliferation , regulation of fatty acid oxidation ,

Nucleus. Cytoplasm. Membrane . Mitochondrion. A small fraction localizes at membranes (By similarity) . Relocates to the cytoplasm when bound to STRAD (STRADA or STRADB) and CAB39/MO25 (CAB39/MO25alpha or CAB39L/MO25beta) . Translocates to the mitochondrion during apoptosis. PTEN promotes cytoplasmic localization. .; [Isoform 2]: Nucleus . Cytoplasm . Predominantly nuclear , but translocates to the cytoplasm in response to metformin or peroxynitrite treatment.