ATP + L-seryl-[protein] = ADP + H(+) + O-phospho-L-seryl-[protein] ATP + L-threonyl-[protein] = ADP + H(+) + O-phospho-L-threonyl-[protein] May be due to intron retention. May be due to intron retention. Belongs to the protein kinase superfamily. Ser/Thr protein kinase family. CRK subfamily.