Enables potassium ion transmembrane transporter activity. Involved in several processes, including T cell chemotaxis; cellular response to potassium ion; and inorganic ion transmembrane transport. Acts upstream of or within several processes, including cellular ion homeostasis; mammary gland duct morphogenesis; and regulation of secretion by cell. Located in several cellular components, including apical plasma membrane; basolateral plasma membrane; and neuronal cell body. Is expressed in several structures, including alimentary system; central nervous system; lung; metanephros; and sensory organ. Human ortholog(s) of this gene implicated in autosomal dominant nonsyndromic deafness 78 and middle cerebral artery infarction. Orthologous to human SLC12A2 (solute carrier family 12 member 2). [provided by Alliance of Genome Resources, Apr 2022]