title: MKS and NPHP modules cooperate to establish basal body/transition zone membrane associations and ciliary gate function during ciliogenesis.
abstract: Meckel-Gruber syndrome (MKS), nephronophthisis (NPHP), and related ciliopathies present with overlapping phenotypes and display considerable allelism between at least twelve different genes of largely unexplained function. We demonstrate that the conserved C. elegans B9 domain (MKS-1, MKSR-1, and MKSR-2), MKS-3/TMEM67, MKS-5/RPGRIP1L, MKS-6/CC2D2A, NPHP-1, and NPHP-4 proteins exhibit essential, collective functions at the transition zone (TZ), an underappreciated region at the base of all cilia characterized by Y-shaped assemblages that link axoneme microtubules to surrounding membrane. These TZ proteins functionally interact as members of two distinct modules, which together contribute to an early ciliogenic event. Specifically, MKS/MKSR/NPHP proteins establish basal body/TZ membrane attachments before or coinciding with intraflagellar transport-dependent axoneme extension and subsequently restrict accumulation of nonciliary components within the ciliary compartment. Together, our findings uncover a unified role for eight TZ-localized proteins in basal body anchoring and establishing a ciliary gate during ciliogenesis, and suggest that disrupting ciliary gate function contributes to phenotypic features of the MKS/NPHP disease spectrum.
authors.affiliation: Department of Cell Biology, University of Alabama, Birmingham, AL 35294, USA.
authors.forename: Corey L
authors.initials: CL
authors.lastname: Williams
authors.forename: Chunmei
authors.initials: C
authors.lastname: Li
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Kida
authors.forename: Peter N
authors.initials: PN
authors.lastname: Inglis
authors.forename: Swetha
authors.initials: S
authors.lastname: Mohan
authors.forename: Lucie
authors.initials: L
authors.lastname: Semenec
authors.forename: Nathan J
authors.initials: NJ
authors.lastname: Bialas
authors.forename: Rachel M
authors.initials: RM
authors.lastname: Stupay
authors.forename: Nansheng
authors.initials: N
authors.lastname: Chen
authors.forename: Oliver E
authors.initials: OE
authors.lastname: Blacque
authors.forename: Bradley K
authors.initials: BK
authors.lastname: Yoder
authors.forename: Michel R
authors.initials: MR
authors.lastname: Leroux
mesh_terms: D000818:Animals; D017173:Caenorhabditis elegans / Q000502:physiology; D029742:Caenorhabditis elegans Proteins / Q000235:genetics / Q000378:metabolism*; D002923:Cilia / Q000502:physiology* / Q000648:ultrastructure*; D002925:Ciliary Motility Disorders / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D004677:Encephalocele / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D052177:Kidney Diseases, Cystic / Q000151:congenital / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism*; D007690:Polycystic Kidney Diseases / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D020033:Protein Isoforms / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012174:Retinitis Pigmentosa
chemical_list: D029742:Caenorhabditis elegans Proteins; C550109:MKS-3 protein, C elegans; D008565:Membrane Proteins; D020033:Protein Isoforms; D011993:Recombinant Fusion Proteins; C501204:nephrocystin 1, C elegans