This gene encodes a serine/threonine protein kinase that functions upstream of mitogen-activated protein kinase (MAPK) signaling. The encoded protein is cleaved into two chains by caspases, the N-terminal fragment (MST3/N) translocates to the nucleus and promotes programmed cells death. There is a pseudogene for this gene on chromosome X. Alternative splicing results in multiple transcript variants. [provided by RefSeq, Nov 2013],catalytic activity:ATP + a protein = ADP + a phosphoprotein.,cofactor:Manganese. Only isoform A requires manganese.,function:Protein kinase that act on both serine and threonine residues.,PTM:Autophosphorylated. Isoform B is activated by phosphorylation by PKA.,similarity:Belongs to the protein kinase superfamily. STE Ser/Thr protein kinase family. STE20 subfamily.,similarity:Contains 1 protein kinase domain.,tissue specificity:Isoform A is ubiquitous. Isoform B is expressed in brain with high expression in hippocampus and cerebral cortex.,
