The ciliopathy gene product Cep290 is required for primary cilium formation and microtubule network organization

Abstract

The mammalian centrosome/cilium complex is composed of the centrosome, the primary cilium, and the centriolar satellites,which together function in key cellular processes including signaling. Defective assembly, maintenance, and function of the centrosome/cilium complex cause the human genetic diseases known as ciliopathies, which are characterized by a multitude of developmentalsyndromes including retinal degeneration and kidney cysts. The molecular mechanisms underlying pathogenesis in ciliopathies remainpoorly understood, which requires structural and functional characterization of the mutated ciliopathy proteins at the cellular level. Tothis end, we elucidated the function and regulation of Cep290, which is the most frequently mutated gene in ciliopathies and importantlyits functions remain poorly understood. First, we generated Cep290-null cells using the CRISPR/Cas9 genome editing approach. Usingfunctional assays, we showed that Cep290-null cells do not ciliate and that they have defects in centriolar satellites dynamics andinterphase microtubule organization. The centriolar satellites were tightly clustered around the centrosome in Cep290-null cells, andthe interphase microtubule network lost its radial organization. Our results provide phenotypic insight into the disease mechanisms ofCep290 ciliopathy mutations and also the tools for studying genotype/phenotype relationships in ciliopathies.