Protein kinase that regulates cellular motility via phosphorylation of membrane proteins. ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] Autophosphorylated. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. sll1574 and sll1575 have been merged into one gene. sll1574 and sll1575 have been merged into one gene.