CEP290 alleles in mice disrupt tissue-specific cilia biogenesis and recapitulate features of syndromic ciliopathies

Abstract

Distinct mutations in the centrosomal-cilia protein CEP290 lead to diverse clinical findings in syndromic ciliopathies. We show that CEP290 localizes to the transition zone in ciliated cells, precisely to the region of Y-linkers between central microtubules and plasma membrane. To create models of CEP290-associated ciliopathy syndromes, we generated Cep290(ko/ko) and Cep290(gt/gt) mice that produce no or a truncated CEP290 protein, respectively. Cep290(ko/ko) mice exhibit early vision loss and die from hydrocephalus. Retinal photoreceptors in Cep290(ko/ko) mice lack connecting cilia, and ciliated ventricular ependyma fails to mature. The minority of Cep290(ko/ko) mice that escape hydrocephalus demonstrate progressive kidney pathology. Cep290(gt/gt) mice die at mid-gestation, and the occasional Cep290(gt/gt) mouse that survives shows hydrocephalus and severely cystic kidneys. Partial loss of CEP290-interacting ciliopathy protein MKKS mitigates lethality and renal pathology in Cep290(gt/gt) mice. Our studies demonstrate domain-specific functions of CEP290 and provide novel therapeutic paradigms for ciliopathies.

A CEP290 C-Terminal Domain Complements the Mutant CEP290 of Rd16 Mice In Trans and Rescues Retinal Degeneration

“…The Cep290 rd16 allele is considered functionally hypomorphic (Chang et al, 2006; Rachel et al, 2015). We therefore examined whether the myosin-tail domain by itself or in combination with the endogenous CEP290 rd16 protein is required to reconstitute CEP290 function.…”

“…The Cep290 rd16 mutation, with a deletion of a 299-residue-long coding sequence, is considered a hypomorph because the mutant mice manifest only sensory defects but no other ciliopathy phenotype. In photoreceptors, the CEP290 rd16 protein allows relatively normal ciliogenesis, as evidenced by the formation of CC and rudimentary OS during post-natal development (Rachel et al, 2012b, 2015). However, it is not able to support normal structure and function, leading to rapid photo-receptor dysfunction and death in the Cep290 rd16/rd16 mouse.…”

“…However, it is not able to support normal structure and function, leading to rapid photo-receptor dysfunction and death in the Cep290 rd16/rd16 mouse. CEP290 is proposed to be localized vertically along the length of the transition zone in the region of the Y-linkers, between the plasma membrane and the microtubule ring (Rachel et al, 2015). Structural integrity of the transition zone is compromised with the CEP290 rd16 mutation, partly due to the absence of the microtubule-binding domain in the mutant CEP290 rd16 protein (Drivas et al, 2013).…”

“…The Cep290 +/ — ;Nrl — / — mouse line was obtained by crossing the Cep290 +/ — mice (Rachel et al, 2015) with the Nrl — / — mice. All mice were kept in central facility maintained by NIH animal care facility personnel with controlled ambient illumination on a 12h light/12h dark cycle.…”

“…No OS structure is observed in mice carrying a Cep290- null mutation, and only rudimentary OSs were detected in a hypomorphic mutant ( rd16 , or Cep290 rd16/rd16 ), indicating the requirement of CEP290 for OS biogenesis (Chang et al, 2006; Rachel et al, 2015). In photoreceptors, CEP290 protein localizes at the connecting cilia (CC), the only intracellular link between light-sensing OS and the biosynthetic inner segments (ISs).…”