May be an autophosphorylating tyrosine kinase, a bifunctional (serine/tyrosine-specific) protein kinase, or a serine kinase that is a substrate for an associated tyrosine kinase. MCK1 is a transcriptional activator of IME1, it stimulates spore maturation, and play a positive regulatory role in both mitotic centromere function and activation of early meiotic gene expression. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] ATP + L-tyrosyl-[protein] = ADP + H(+) + O-phospho-L-tyrosyl-[protein] Phosphorylated at tyrosine and serine. Present with 396 molecules/cell in log phase SD medium. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.