Enables organic anion transmembrane transporter activity. Acts upstream of or within anion transport. Located in membrane. Is expressed in choroid invagination; choroid plexus; diencephalon roof plate; medulla oblongata part of 4th ventricle choroid plexus; and metencephalon part of 4th ventricle choroid plexus. Orthologous to human SLCO1A2 (solute carrier organic anion transporter family member 1A2). [provided by Alliance of Genome Resources, Apr 2022]