Enables phosphatase binding activity. Acts upstream of or within negative regulation of phosphatidylinositol 3-kinase signaling and sensory perception of sound. Located in several cellular components, including apical plasma membrane; nucleus; and stereocilium. Is expressed in cochlea epithelium and organ of Corti. Orthologous to human SLC9A3R2 (SLC9A3 regulator 2). [provided by Alliance of Genome Resources, Apr 2022]