Buffers cytosolic calcium. May stimulate a membrane Ca(2+)-ATPase and a 3',5'-cyclic nucleotide phosphodiesterase. Interacts with RANBP9. Expressed in the modiolar nerve root and in bushy neurons in the ventral cochlear nucleus (at protein level). This protein has four functional calcium-binding sites; potential sites II and VI have lost affinity for calcium. Belongs to the calbindin family.