Enables calmodulin binding activity and protein serine/threonine kinase activity. Involved in several processes, including asymmetric protein localization involved in cell fate determination; cell division; and determination of adult lifespan. Located in cell cortex. Expressed widely. Used to study Peutz-Jeghers syndrome. Human ortholog(s) of this gene implicated in several diseases, including Peutz-Jeghers syndrome; familial melanoma; and female reproductive organ cancer (multiple). Is an ortholog of human STK11 (serine/threonine kinase 11).