Loss of the ciliary kinase nek8 causes left-right asymmetry defects
- Authors
- Manning, D.K., Sergeev, M., van Heesbeen, R.G., Wong, M.D., Oh, J.H., Liu, Y., Henkelman, R.M., Drummond, I., Shah, J.V., and Beier, D.R.
- ID
- ZDB-PUB-130108-4
- Date
- 2013
- Source
- Journal of the American Society of Nephrology : JASN 34(1): 100-112 (Journal)
- Registered Authors
- Beier, David R., Drummond, Iain, Liu, Yan
- Keywords
- none
- MeSH Terms
-
- Homozygote
- Cilia/physiology*
- Zebrafish
- Biomarkers/metabolism
- Heart Defects, Congenital/embryology
- Polycystic Kidney Diseases/genetics*
- Animals
- Disease Models, Animal
- Body Patterning*
- Female
- Male
- Mice
- Phenotype
- TRPP Cation Channels/metabolism
- Heterozygote
- Protein Serine-Threonine Kinases/genetics*
- Protein Serine-Threonine Kinases/metabolism
- Mice, Inbred C57BL
- PubMed
- 23274954 Full text @ J. Am. Soc. Nephrol.
A missense mutation in mouse Nek8, which encodes a ciliary kinase, produces the juvenile cystic kidneys (jck) model of polycystic kidney disease, but the functions of Nek8 are incompletely understood. Here, we generated a Nek8-null allele and found that homozygous mutant mice die at birth and exhibit randomization of left-right asymmetry, cardiac anomalies, and glomerular kidney cysts. The requirement for Nek8 in left-right patterning is conserved, as knockdown of the zebrafish ortholog caused randomized heart looping. Ciliogenesis was intact in Nek8-deficient embryos and cells, but we observed misexpression of left-sided marker genes early in development, suggesting that nodal ciliary signaling was perturbed. We also generated jck/Nek8 compound heterozygotes; these mutants developed less severe cystic disease than jck homozygotes and provided genetic evidence that the jck allele may encode a gain-of-function protein. Notably, NEK8 and polycystin-2 (PC2) proteins interact, and we found that Nek8-/- and Pkd2-/- embryonic phenotypes are strikingly similar. Nek8-deficient embryos and cells did express PC2 normally, which localized properly to the cilia. However, similar to cells lacking PC2, NEK8-depleted inner medullary collecting duct cells exhibited a defective response to fluid shear, suggesting that NEK8 may play a role in mediating PC2-dependent signaling.