FunctionEssential role in G1 cell cycle arrest. Phosphorylates and activates members of the AMPK-related subfamily of protein kinases. Tumor suppressor.
Tissue specificityUbiquitously expressed. Strongest expression in testis and fetal liver.
Involvement in diseaseDefects 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. Defects in STK11 have been associated with testicular tumors (TEST) [MIM:273300]. A common solid malignancy in males. Germ cell tumors of the testis constitute 95% of all testicular neoplasms.
Sequence similaritiesBelongs to the protein kinase superfamily. CAMK Ser/Thr protein kinase family. LKB1 subfamily. Contains 1 protein kinase domain.
Post-translational modificationsPhosphorylated by a cAMP-dependent protein kinase.
Cellular localizationNucleus. Cytoplasm. Relocates to the cytoplasm when bound to CAB39 and STRAD or CAB39 and ALS2CR2.