The cell biology of Nek8, defective in cystic kidney diseases

Ciliopathies, which are caused by defects in cilia and basal bodies include the cystic kidney diseases. Mutations in the NIMA-related kinase, Nek8, are associated with the cystic kidney disease, nephronophthisis, and cause renal cysts in juvenile cystic kidney (jck) mice. In this study, I find that Nek8 localizes to cilia in cell culture and in developing mouse kidney. Specifically, Nek8 is expressed in cilia of epithelial cells lining the tubules of the uretic bud lineage. Cystogenic forms of Nek8 show differential ciliary localization, but do not affect ciliogenesis. In jck mouse kidney, ciliary Nek8 localization is reduced. These data indicate Nek8 functions within the cilium and defects in localization are correlated with renal cystogenesis.