CIB2

The protein encoded by this gene is similar to that of KIP/CIB, calcineurin B, and calmodulin. The encoded protein is a calcium-binding regulatory protein that interacts with DNA-dependent protein kinase catalytic subunits (DNA-PKcs), and it is involved in photoreceptor cell maintenance. Mutations in this gene cause deafness, autosomal recessive, 48 (DFNB48), and also Usher syndrome 1J (USH1J). Alternative splicing results in multiple transcript variants. [provided by RefSeq, Jul 2014]

Full Name

Calcium And Integrin Binding Family Member 2

Function

Calcium-binding protein critical for proper photoreceptor cell maintenance and function. Plays a role in intracellular calcium homeostasis by decreasing ATP-induced calcium release (PubMed:23023331, PubMed:26173970, PubMed:26426422).

May be involved in the mechanotransduction process (By similarity).

Biological Process

Calcium ion homeostasis Source: UniProtKB
Cellular response to ATP Source: UniProtKB
Photoreceptor cell maintenance Source: UniProtKB
Positive regulation of cytosolic calcium ion concentration Source: UniProtKB

Cellular Location

Sarcolemma; Cytoplasm; Stereocilium; Photoreceptor inner segment; Photoreceptor outer segment. Colocalized with ITGA7 at the myotendinous junctions (MTJ) and at the neuromuscular junctions (NMJ) (By similarity). Localizes in the cuticular plate along and at the tip of the stereocilia of vestibular sensory hair cells (PubMed:26173970, PubMed:26426422).

Involvement in disease

Deafness, autosomal recessive, 48 (DFNB48):
A form of non-syndromic sensorineural hearing loss. Sensorineural deafness results from damage to the neural receptors of the inner ear, the nerve pathways to the brain, or the area of the brain that receives sound information. DFNB48 patients have prelingual onset of severe to profound sensorineural hearing loss affecting all frequencies.
Usher syndrome 1J (USH1J):
USH is a genetically heterogeneous condition characterized by the association of retinitis pigmentosa with sensorineural deafness. Age at onset and differences in auditory and vestibular function distinguish Usher syndrome type 1 (USH1), Usher syndrome type 2 (USH2) and Usher syndrome type 3 (USH3). USH1 is characterized by profound congenital sensorineural deafness, absent vestibular function and prepubertal onset of progressive retinitis pigmentosa leading to blindness.