Component of the DZIP1-Fam92-Cby complex which promotes ciliogenesis in sensory neurons and spermatocytes by acting downstream of Cep290 to initiate early ciliary membrane formation and thus transition zone (TZ) assembly (PubMed:31821146, PubMed:33370260). During spermatogenesis, also regulates distal elongation of the basal-body and their docking (anchoring) to the plasma membrane and as a consequence, regulates the initiation and proper elongation of axonemal microtubules (PubMed:31821146). Within the complex, required to recruit or stabilize Rab8, Fam92 and Cby at the distal basal body of cilia to promote early ciliary membrane formation and initiate TZ assembly (PubMed:31821146). Also acts with Fam92 to restrict cep290 localization to the proximal part of the TZ (PubMed:31821146). May also be involved in recruitment or stabilization of Mks1 at the TZ (PubMed:31821146). Component of a ciliary transition zone (TZ)-localized complex composed of DZIP1, Fam92 and Cby (PubMed:31821146). Interacts directly with Cby (PubMed:31821146, PubMed:33370260). Interacts with cep290 (via N-terminus) (PubMed:33370260). Interacts (via N-terminus) with Rab8 (PubMed:33370260). Localizes at the transition zone (TZ) in type I sensory neurons and spermatocytes (PubMed:31821146, PubMed:33370260). In spermatocytes, localizes along the TZ membranes (PubMed:33370260). Localizes at the centriolar distal ends of early spermatocytes and in elongating spermatids, when the TZ migrates away from the basal body, localizes at the ring centriole (PubMed:31821146, PubMed:33370260). In sensory neurons, localizes between the transition fiber and TZ core components (PubMed:33370260). In neurons of the second and third antennal segments, expressed at the tip of the dendrites. Belongs to the DZIP C2H2-type zinc-finger protein family.