Involved in ciliogenesis. The function in an early step in cilia formation depends on its association with CEP290/NPHP6 (By similarity). 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 (By similarity). Interacts with calmodulin (PubMed:15723066). Interacts with CEP290/NPHP6; IQCB1/NPHP5 and CEP290/NPHP6; are proposed to form a functional NPHP5-6 module localized to the centrosome. Interacts with ATXN10. Interacts with NPHP1, INVS, NPHP4 and RPGRIP1L; these interactions likely require additional interactors (PubMed:21565611). Associates with the BBSome complex; interacts with BBS1, BBS2, BBS4, BBS5, BBS7, BBS8 and BBS9 (By similarity). Localization to the centrosome depends on the interaction with CEP290. Localized to the outer segment and connecting cilia of photoreceptor cells. The IQ domains mediate the interaction with calmodulin.