The gene encodes an EF hand-containing small calcium binding protein. It is an integral subunit component of Kv4/D (Shal)-type voltage-gated rapidly inactivating A-type potassium channels. Kv4 potassium channels regulate action potentials in neurons and cardiac myocytes. The coexpression of ABP with pore-forming Kv4 alpha subunits causes changes in the gating and amplitude of Kv4 currents, thus profoundly affect the intracellular trafficking and molecular properties of Kv4.2 alpha subunits. It also cause a dramatic redistribution of Kv4.2, releasing intrinsic endoplasmic reticulum retention and allowing for trafficking to the cell surface. It may regulate A-type currents, and hence neuronal excitability, in response to changes in intracellular calcium. It maps to 5q35.1 region of human chromosome. Alternative splicing results in multiple transcript variant encoding different isoforms. Isoform 1 and isoform 2 are expressed in brain and kidney.