Plays a role in motile cilium function, possibly by acting on outer dynein arm assembly (PubMed:24094744, PubMed:26904945). Seems to be important for initiation rather than maintenance of cilium motility (PubMed:26904945). Required for correct positioning of cilia at the apical cell surface, suggesting an additional role in the planar cell polarity (PCP) pathway (PubMed:26904945). May suppress canonical Wnt signaling activity (PubMed:26904945). Interacts with dnaaf1/swt. Interacts with lrrc6/sea. Interacts with dvl (via DEP and PDZ domains). Appears in cytoplasmic puncta, compatible with a centrosomal localization. Strongly expressed in ciliated tissues of the embryonic trunk, including the pronephric ducts and spinal canal. Detected at the 1-cell embryo stage, probably due to inheritance of maternal transcripts. At the 50% ebiboly stage, detected in dorsal forerunner cells. At the 3-somite stage, found in Kupffer's vesicle. At the 8-somite stage, expressed in the pronephros, the floorplate of the neural tube, and otic vesicles. Expression in the pronephros continues to the 24-somite stage. Larval lethal (PubMed:26904945). Animals show strong ciliopathy phenotypes, including pronephric cysts, axis curvature, left-right asymmetry defects and hydrocephalus (PubMed:26904945). Kidney tubules are dilated and polarity of cilia in the epithelium is disorganized (PubMed:26904945). Cilia length and number appear normal, but outer dynein arms are missing and cilia are paralyzed (PubMed:26904945). Morpholino knockdown of the protein results in similar phenotypes (PubMed:24094744, PubMed:26904945). Belongs to the CFAP298 family.