IQCB1

This gene encodes a nephrocystin protein that interacts with calmodulin and the retinitis pigmentosa GTPase regulator protein. The encoded protein has a central coiled-coil region and two calmodulin-binding IQ domains. It is localized to the primary cilia of renal epithelial cells and connecting cilia of photoreceptor cells. The protein is thought to play a role in ciliary function. Defects in this gene result in Senior-Loken syndrome type 5. Alternative splicing results in multiple transcript variants. A pseudogene of this gene is found on chromosome 6.

Full Name

IQ motif containing B1

Function

Involved in ciliogenesis. The function in an early step in cilia formation depends on its association with CEP290/NPHP6 (PubMed:21565611, PubMed:23446637).
Involved in regulation of the BBSome complex integrity, specifically for presence of BBS2 and BBS5 in the complex, and in ciliary targeting of selected BBSome cargos. May play a role in controlling entry of the BBSome complex to cilia possibly implicating CEP290/NPHP6 (PubMed:25552655).

Biological Process

Cilium assemblyISS:UniProtKB
Maintenance of animal organ identityManual Assertion Based On ExperimentIMP:HGNC-UCL
Photoreceptor cell maintenanceManual Assertion Based On ExperimentIMP:HGNC-UCL

Cellular Location

Cytoplasm, cytoskeleton, microtubule organizing center, centrosome; Cytoplasm, cytoskeleton, microtubule organizing center, centrosome, centriole. Localization to the centrosome depends on the interaction with CEP290/NPHP6.

Involvement in disease

Senior-Loken syndrome 5 (SLSN5):
A renal-retinal disorder characterized by progressive wasting of the filtering unit of the kidney (nephronophthisis), with or without medullary cystic renal disease, and progressive eye disease. Typically this disorder becomes apparent during the first year of life.
Leber congenital amaurosis 10 (LCA10):
A severe dystrophy of the retina, typically becoming evident in the first years of life. Visual function is usually poor and often accompanied by nystagmus, sluggish or near-absent pupillary responses, photophobia, high hyperopia and keratoconus.