catalytic activity:ATP + a protein = ADP + a phosphoprotein.,cofactor:Magnesium.,enzyme regulation:Activated by binding of S100B which releases autoinhibitory N-lobe interactions, enabling ATP to bind and the autophosphorylation of Ser-281. Thr-444 then undergoes calcium-dependent phosphorylation by an upstream kinase. Interactions between phosphorylated Thr-444 and the N-lobe promote additional structural changes that complete the activation of the kinase. Autoinhibition is also released by the binding of MOB1/MOBKL1A and MOB2/HCCA2 to the N-terminal of STK38.,similarity:Belongs to the protein kinase superfamily. AGC Ser/Thr protein kinase family.,similarity:Contains 1 AGC-kinase C-terminal domain.,similarity:Contains 1 protein kinase domain.,subcellular location:Low levels present in the cytoplasm.,subunit:Homodimeric S100B binds two molecules of STK38. Interacts with MOB1 and MOB2.,tissue specificity:Ubiquitously expressed with highest levels observed in peripheral blood leukocytes.,
