The ciliopathy-associated CPLANE proteins direct basal body recruitment of intraflagellar transport machinery

John Wallingford and colleagues combine proteomics, in vivo imaging and genetic analyses to identify a new ciliopathy-associated protein module, which they call CPLANE. They show that CPLANE proteins, which include Fuzzy, Inturned and Wdpcp, interact with Jbts17 at basal bodies, where they act to recruit a specific subset of intraflagellar transport proteins. Cilia use microtubule-based intraflagellar transport (IFT) to organize intercellular signaling. Ciliopathies are a spectrum of human diseases resulting from defects in cilia structure or function. The mechanisms regulating the assembly of ciliary multiprotein complexes and the transport of these complexes to the base of cilia remain largely unknown. Combining proteomics, in vivo imaging and genetic analysis of proteins linked to planar cell polarity (Inturned, Fuzzy and Wdpcp), we identified and characterized a new genetic module, which we term CPLANE (ciliogenesis and planar polarity effector), and an extensive associated protein network. CPLANE proteins physically and functionally interact with the poorly understood ciliopathy-associated protein Jbts17 at basal bodies, where they act to recruit a specific subset of IFT-A proteins. In the absence of CPLANE, defective IFT-A particles enter the axoneme and IFT-B trafficking is severely perturbed. Accordingly, mutation of CPLANE genes elicits specific ciliopathy phenotypes in mouse models and is associated with ciliopathies in human patients.