Normal ciliogenesis requires synergy between the cystic kidney disease genes MKS-3 and NPHP-4.
Cilia dysfunction contributes to renal cyst formation in multiple human syndromes including nephronophthisis (NPHP), Meckel-Gruber syndrome (MKS), Joubert syndrome (JBTS), and Bardet-Beidl syndrome (BBS). Although genetically heterogeneous, these diseases share several loci that affect cilia and/or basal body proteins, but the functions and interactions of these gene products are incompletely understood. Here, we report that the ciliated sensory neurons (CSNs) of C. elegans express the putative transmembrane protein MKS-3, which localized to the distal end of their dendrites and to the cilium base but not to the cilium itself. Localization of MKS-3 and other known MKS and NPHP proteins partially overlapped. By analyzing mks-3 mutants, we found that ciliogenesis did not require MKS-3; instead, cilia elongated and cilia-mediated chemoreception was abnormal. Genetic analysis indicated that mks-3 functions in a pathway with other mks genes. Furthermore, mks-1 and mks-3 genetically interacted with a separate pathway (involving nphp-1 and nphp-4) to influence proper positioning, orientation, and formation of cilia. Combined disruption of nphp and mks pathways had cell nonautonomous effects on C. elegans sensilla. Taken together, these data demonstrate the importance of mutational load on the presentation and severity of ciliopathies and expand the understanding of the interactions between ciliopathy genes.
Williams
Corey L
CL
Department of Cell Biology, University of Alabama at Birmingham Medical Center, Birmingham, Alabama, USA.
Masyukova
Svetlana V
SV
Yoder
Bradley K
BK
D000483:Alleles; D000818:Animals; D017173:Caenorhabditis elegans; D029742:Caenorhabditis elegans Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002633:Chemotaxis; D002923:Cilia / Q000378:metabolism; D005786:Gene Expression Regulation; D052177:Kidney Diseases, Cystic / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D011984:Sensory Receptor Cells / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism
D029742:Caenorhabditis elegans Proteins; C410596:DAF-19 protein, C elegans; C550109:MKS-3 protein, C elegans; D008565:Membrane Proteins; D014157:Transcription Factors; C501205:nephrocystin 4, C elegans