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. Modulates KCND2/Kv4.2 currents (PubMed:14572458). In vitro, modulates KCND1/Kv4.1 currents (By similarity). Increases the presence of KCND2 at the cell surface. Component of heteromultimeric potassium channels (PubMed:19713751). Identified in potassium channel complexes containing KCND1, KCND2, KCND3, KCNIP1, KCNIP2, KCNIP3, KCNIP4, DPP6 and DPP10 (PubMed:19713751). Part of a heterooctamer composed of the tetrameric channel and four KCNIP1 chains (By similarity). Interacts with KCND3 and the N-terminal domain of KCND2. Probably part of a complex consisting of KCNIP1, KCNIP2 isoform 3 and KCND2. Self-associates to form homodimers and homotetramers. Interacts with KCNIP2 isoform 3 in a calcium-dependent manner (By similarity). Expressed in brain. Found in a subpopulation of neurons widely distributed and enriched in Purkinje cells of the cerebellum and in the reticular thalamic and medial habenular nuclei. Belongs to the recoverin family. Truncated N-terminus.