Essential for ciliogenesis in sensory neurons and spermatocytes (PubMed:25447994, PubMed:30013109, PubMed:31821146, PubMed:33370260). During neuron and spermatocyte ciliogenesis, essential for initiating transition zone (TZ) assembly and is required for the formation of diverse connections between microtubules and between microtubules and the membrane (PubMed:25447994, PubMed:30013109, PubMed:31821146, PubMed:33370260). Regulates TZ assembly by recruiting DZIP1 to the plasma membrane where it promotes early ciliary membrane formation resulting in the initiation of TZ assembly (PubMed:31821146, PubMed:33370260). Interacts (via N-terminus) with DZIP1. Localizes at the transition zone (TZ), a region between the basal body and the ciliary axoneme in the olfactory, auditory and spermatocyte system (PubMed:30013109, PubMed:33370260). In sensory neurons, localizes to the transition zone at the tip of the mother centriole (PubMed:25447994). In germ cells, component of the spermatocyte primary cilium and spermatid ciliary cap (PubMed:25447994, PubMed:27646273, PubMed:27577095). Expressed in sensory neurons type I and in germ cells (at protein level). The C-terminus orients towards the microtubules and the N-terminus orients towards the membrane in a 9-fold symmetric manner. Adults are severely uncoordinated and exhibit disorganized spermatid cysts with dispersed nuclei, likely as a consequence of the severe defects in axonemal elongation (PubMed:31821146). RNAi-mediated knockdown in developing sensory neurons results in defective microtubule (MT)-microtubule (MT) and microtubule-membrane connections (Y linkers) ultimately affecting cilia formation leading to olfactory and gravitaxis behavioral defects (PubMed:30013109). RNAi-mediated knockdown in spermatocytes results in defective transition zone assembly including increased distance between microtubules (MT) and MT-membrane causing defective cilia (PubMed:30013109).