serine/threonine kinase 3(STK3) Homo sapiens This gene encodes a serine/threonine protein kinase activated by proapoptotic molecules indicating the encoded protein functions as a growth suppressor. Cleavage of the protein product by caspase removes the inhibitory C-terminal portion. The N-terminal portion is transported to the nucleus where it homodimerizes to form the active kinase which promotes the condensation of chromatin during apoptosis. Multiple transcript variants encoding different isoforms have been found for this gene. [provided by RefSeq, Jan 2012],catalytic activity:ATP + a protein = ADP + a phosphoprotein.,cofactor:Magnesium.,enzyme regulation:Inhibited by the C-terminal non-catalytic region. Activated by caspase-cleavage. Full activation also requires homodimerization and autophosphorylation of Thr-180, which are inhibited by the proto-oncogene product RAF1.,function:Stress-activated, pro-apoptotic kinase which, following caspase-cleavage, enters the nucleus and induces chromatin condensation followed by internucleosomal DNA fragmentation. Phosphorylates NKX2-1 (By similarity). Phosphorylates and activates LATS1 and LATS2.,similarity:Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family. STE20 subfamily.,similarity:Contains 1 protein kinase domain.,similarity:Contains 1 SARAH domain.,subcellular location:The caspase-cleaved form cycles between nucleus and cytoplasm.,subunit:Homodimer, mediated via the coiled-coil region. Interacts with NORE1, which inhibits autoactivation (By similarity). Interacts with and stabilizes SAV1. Interacts with RAF1, which prevents dimerization and phosphorylation. Interacts with RASSF1, which leads to enzyme activation.,tissue specificity:Expressed at high levels in adult kidney, skeletal and placenta tissues and at very low levels in adult heart, lung and brain tissues.,
