To provide further insights into the retinal function of POC1B, we aimed to identify retinal proteins interacting with POC1B by using a GAL4-based interaction trap screen in yeast of a retinal cDNA library. Out of the four different bait fragments of POC1B employed, only the coiled-coil region was found to yield one significant interactor: FAM161A. Interestingly, mutations in FAM161A lead to another retinal ciliopathy, autosomal-recessive RP (RP28).27,28 Binding of FAM161A was validated with coimmunoprecipitation and colocalization studies (Figure 5). Although the interaction was initially detected with a fragment containing the coiled-coil region of POC1B, introduction of the two POC1B variants in the WD40 domain of the full-length protein strongly decreased its interaction with FAM161A, reiterating the structural importance of this domain. Because FAM161A was found to be a retinal-ciliopathy-associated protein,21,37 the decreased interaction we observed with this retina-specific protein might induce degeneration of rod photoreceptors as a result of POC1B mutations in individuals with CRD.