KLHL3 Knockout Mice Reveal the Physiological Role of KLHL3 and the Pathophysiology of Pseudohypoaldosteronism Type II Caused by Mutant KLHL3

Mol Cell Biol. 2017 Mar 17;37(7):e00508-16. doi: 10.1128/MCB.00508-16. Print 2017 Apr 1.

Abstract

Mutations in the with-no-lysine kinase 1 (WNK1), WNK4, kelch-like 3 (KLHL3), and cullin3 (CUL3) genes are known to cause the hereditary disease pseudohypoaldosteronism type II (PHAII). It was recently demonstrated that this results from the defective degradation of WNK1 and WNK4 by the KLHL3/CUL3 ubiquitin ligase complex. However, the other physiological in vivo roles of KLHL3 remain unclear. Therefore, here we generated KLHL3-/- mice that expressed β-galactosidase (β-Gal) under the control of the endogenous KLHL3 promoter. Immunoblots of β-Gal and LacZ staining revealed that KLHL3 was expressed in some organs, such as brain. However, the expression levels of WNK kinases were not increased in any of these organs other than the kidney, where WNK1 and WNK4 increased in KLHL3-/- mice but not in KLHL3+/- mice. KLHL3-/- mice also showed PHAII-like phenotypes, whereas KLHL3+/- mice did not. This clearly demonstrates that the heterozygous deletion of KLHL3 was not sufficient to cause PHAII, indicating that autosomal dominant type PHAII is caused by the dominant negative effect of mutant KLHL3. We further demonstrated that the dimerization of KLHL3 can explain this dominant negative effect. These findings could help us to further understand the physiological roles of KLHL3 and the pathophysiology of PHAII caused by mutant KLHL3.

Keywords: NaCl cotransporter; distal convoluted tubule; hypertension; kelch-like 3 (KLHL3); kidney; with-no-lysine kinase (WNK).

MeSH terms

  • Adaptor Proteins, Signal Transducing
  • Animals
  • Gene Knock-In Techniques
  • Genes, Dominant
  • Kidney / enzymology
  • Kidney / pathology
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Microfilament Proteins / deficiency
  • Microfilament Proteins / genetics*
  • Models, Biological
  • Mutant Proteins / metabolism
  • Mutation / genetics*
  • Phenotype
  • Phosphorylation
  • Protein Multimerization
  • Protein Serine-Threonine Kinases / metabolism
  • Pseudohypoaldosteronism / blood
  • Pseudohypoaldosteronism / genetics*
  • Pseudohypoaldosteronism / physiopathology*
  • Tissue Distribution

Substances

  • Adaptor Proteins, Signal Transducing
  • KLHL3 protein, mouse
  • Microfilament Proteins
  • Mutant Proteins
  • Protein Serine-Threonine Kinases