Enables ribosomal protein S6 kinase activity. Acts upstream of or within several processes, including cardiac muscle cell apoptotic process; oocyte maturation; and regulation of gene expression. Located in cytoplasm and meiotic spindle. Is expressed in several structures, including alimentary system; early conceptus; genitourinary system; nervous system; and sensory organ. Orthologous to human RPS6KA2 (ribosomal protein S6 kinase A2). [provided by Alliance of Genome Resources, Apr 2022]