Involved in vesicle trafficking and required for ciliogenesis, formation of primary non-motile cilium, and recruitment of RAB8A to the basal body of primary cilium. Component of the tectonic-like complex, a complex localized at the transition zone of primary cilia and acting as a barrier that prevents diffusion of transmembrane proteins between the cilia and plasma membranes. Involved in neuronal differentiation. As a positive modulator of classical Wnt signaling, may play a crucial role in ciliary signaling during cerebellum embryonic development. Self-associates. Part of the tectonic-like complex (also named B9 complex). Interacts with MKS1. Interacts with NPHP1; probably as heterodimers and/or AHI1(2):NPHP1(2) heterotetramers. Interacts (via SH3 domain) with the dynamin GTPase DNM2. Interacts with HAP1; probably as AHI1(2):HAP1(2) heterotetramers. Interacts with RAB8A. Interacts with CEND1 (By similarity). Interacts with SPATA7 (By similarity). In the retinal photoreceptor cell layer, localizes at the connecting cilium.