Enables potassium channel regulator activity and transmembrane transporter binding activity. Involved in negative regulation of delayed rectifier potassium channel activity and positive regulation of voltage-gated calcium channel activity. Located in plasma membrane. Human ortholog(s) of this gene implicated in Brugada syndrome 6 and hypokalemic periodic paralysis. Orthologous to human KCNE3 (potassium voltage-gated channel subfamily E regulatory subunit 3). [provided by Alliance of Genome Resources, Apr 2022]