Enables protein serine/threonine phosphatase inhibitor activity. Involved in regulation of phosphatase activity. Predicted to be located in cytosol. Is expressed in alimentary system; ganglia; and neural retina. Human ortholog(s) of this gene implicated in familial hypercholesterolemia. Orthologous to human PPP1R17 (protein phosphatase 1 regulatory subunit 17). [provided by Alliance of Genome Resources, Apr 2022]