DdMLCK: Myosin light chain kinase-A (D. discoideum)

摘要: Myosin light chain kinase-A (MLCK-A) activates myosin ATPase and contractile activity by phosphorylating the 18 kDa regulatory chain. In Dictyostelium discoideum (D. discoideum), is required for cytokinesis fruiting body formation. Light phosphorylation thought to regulate its during these processes. MLCK-A encoded mlkA locus. Disruption of this gene results in impaired ability undergo cytokinesis. Substitution autophosphorylated Thr with Ala (T289A) decreases 7-fold vitro. comprises a compact catalytic domain (1–266) short inhibitory (267–295). Autophosphorylation T298 enzyme. MLCKs have been characterized from several higher eukaryotes—SmMLCK, SkMLCK, Twn. These additional domains not found MLCK-A. Unlike other MLCKs, directly activated Ca2+/calmodulin. can be assayed transfer radioactivity [g 32P]ATP D. or synthetic peptide MASTKRRLNREESSWLCONH2, corresponding residues 1–17