Enables protein serine/threonine kinase activity. Acts upstream of or within protein autophosphorylation. Located in endoplasmic reticulum; membrane; and nuclear envelope. Is expressed in several structures, including cerebral cortex; dorsal mesogastrium; gonad; hemolymphoid system; and yolk sac. Orthologous to human VRK2 (VRK serine/threonine kinase 2). [provided by Alliance of Genome Resources, Apr 2022]