Serine/threonine-protein kinase involved in the control of sugar metabolism and translation. Phosphorylates UGP1, which is required for normal glycogen and beta-(1,6)-glucan synthesis. This phosphorylation shifts glucose partitioning toward cell wall glucan synthesis at the expense of glycogen synthesis. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Present with 967 molecules/cell in log phase SD medium. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family.