Enables identical protein binding activity; iodide transmembrane transporter activity; and ligand-gated monoatomic ion channel activity. Involved in several processes, including monoatomic anion transport; mucus secretion; and positive regulation of insulin secretion involved in cellular response to glucose stimulus. Located in apical plasma membrane and nucleoplasm. Implicated in Moyamoya disease. [provided by Alliance of Genome Resources, Jul 2025]