Calcium and integrin-binding protein 2 (CIB2)

Calcium and integrin-binding protein 2 (CIB2) is a small, cytoplasmic EF-hand protein highly homologous to other CIB family members. It binds both Ca²⁺ and Mg²⁺ ions through its C-terminal EF-hands, functioning as an intracellular calcium sensor. CIB2 is essential for normal auditory function; it regulates mechanoelectrical transduction in cochlear hair cells and maintains hair cell stereocilia bundle morphology and survival. CIB2 also interacts with integrins, influencing signaling in muscle and platelets and playing roles in other cellular processes such as autophagy. Mutations in CIB2 are a known cause of autosomal recessive non-syndromic deafness (DFNB48) and Usher syndrome type 1J, disorders characterized by auditory and, in the case of Usher syndrome, visual loss. CIB2 is encoded by the CIB2 gene on chromosome 15q25.1, producing a 187-amino acid protein of approximately 21.6 kDa. Despite its structural and functional significance, CIB2 is not currently known as a direct therapeutic drug target, and there are no approved drugs specifically targeting it[1][2][3].

Other names

Kinase-interacting protein 2KIP2KIP 2DFNB48USH1JDNA-dependent protein kinase catalytic subunit-interacting protein 2