Properties of the protein kinase that phosphorylates prothymosin α

摘要: The prothymosin a kinase (ProTαK) is an apparently novel enzyme that responsible for the phosphorylation of α (ProTα), involved in proliferation mammalian cells. present study investigated properties this enzyme. ProTαK more effectively activated by Mn2+ than other divalent cations, and its activity unaffected RNA. Its principal substrate proliferating cells appears to be ProTa. Both vivo vitro, it unable phosphorylate peptides thymosin α1 α11, derived from amino terminus ProTα, despite fact sites ProTα are contained within part sequence. In trials vivo, inhibition gene expression abolished both activity. located cytosolic fractions throughout cell cycle. activity, which dependent on proliferation, increases markedly during S phase begins decline as enters G2. Studies effects activators inhibitors protein kinases signal transduction pathways suggest mitogen-initiated pathway PKC; however, PKC does not itself ProTαK, therefore presumably phosphorylated another kinase.