Regulatory subunit of Kv4/D (Shal)-type voltage-gated rapidly inactivating A-type potassium channels. Regulates channel density, inactivation kinetics and rate of recovery from inactivation in a calcium-dependent and isoform-specific manner. In vitro, modulates KCND1/Kv4.1 and KCND2/Kv4.2 currents. Increases the presence of KCND2 at the cell surface.
Subcellular locations: Cell membrane, Cytoplasm, Cell projection, Dendrite
Isoform 1 and isoform 2 are expressed in brain and kidney. Isoform 1 is also expressed in liver, pancreas, skeletal muscle, small intestine and testis. Isoform 2 is also expressed in lung, pancreas, leukocytes, prostate and thymus.