ROMK expression remains unaltered in a mouse model of familial hyperkalemic hypertension caused by the CUL3Δ403‐459mutation

Autor: Meena Murthy, Thimo Kurz, Kevin M. O'Shaughnessy
Přispěvatelé: O'Shaughnessy, Kevin [0000-0002-1476-7566], Apollo - University of Cambridge Repository
Jazyk: angličtina
Rok vydání: 2016
Předmět:
0301 basic medicine
Physiology
Pseudohypoaldosteronism
Mutant
Blood Pressure
Kidney
medicine.disease_cause
Membrane Potentials
Xenopus laevis
ubiquitin-ligase complex
Ubiquitin
Gene Knock-In Techniques
ROMK
WNK kinases
Original Research
Mutation
biology
Microfilament Proteins
Cullin Proteins
Ubiquitin ligase
Cell biology
WNK4
Phenotype
Regulatory Pathways
Ubiquitin ligase complex
ubiquitin‐ligase complex
Endocrine and Metabolic Conditons
Disorders and Treatments
medicine.medical_specialty
Genetic Conditions Disorders and Treatments
Mice
Transgenic
Protein Serine-Threonine Kinases
Transfection
Cell Line
03 medical and health sciences
Physiology (medical)
Internal medicine
medicine
Animals
Genetic Predisposition to Disease
Potassium Channels
Inwardly Rectifying
Adaptor Proteins
Signal Transducing
Cullin-3
urogenital system
Cullin‐3
hyperkalemia
proteasome
030104 developmental biology
Endocrinology
Oocytes
Potassium
biology.protein
Neddylation
Protein Processing
Post-Translational
Biomarkers
Zdroj: Physiological Reports
ISSN: 2051-817X
Popis: Familial hyperkalemic hypertension (FHHt) is a rare inherited form of salt-dependent hypertension caused by mutations in proteins that regulate the renal Na(+)-Cl(-) cotransporter NCC Mutations in four genes have been reported to cause FHHt including CUL3 (Cullin3) that encodes a component of a RING E3 ligase. Cullin-3 binds to WNK kinase-bound KLHL3 (the substrate recognition subunit of the ubiquitin ligase complex) to promote ubiquitination and proteasomal degradation of WNK kinases. Deletion of exon 9 from CUL3 (affecting residues 403-459, CUL3(Δ403-459)) causes a severe form of FHHt (PHA2E) that is recapitulated closely in a knock-in mouse model. The loss of functionality of CUL3(Δ403-459) and secondary accumulation of WNK kinases causes substantial NCC activation. This accounts for the hypertension in FHHt but the origin of the hyperkalemia is less clear. Hence, we explored the impact of CUL3(Δ403-459) on expression of the distal secretory K channel, ROMK, both in vitro and in vivo. We found that expressing wild-type but not the CUL3(Δ403-459) mutant form of CUL3 prevented the suppression of ROMK currents by WNK4 expressed in Xenopus oocytes. The mutant CUL3 protein was also unable to affect ROMK-EGFP protein expression at the surface of mouse M-1 cortical collecting duct (CCD) cells. The effects of CUL3 on ROMK expression in both oocytes and M-1 CCD cells was reduced by addition of the neddylation inhibitor, MLN4924. This confirms that neddylation is important for CUL3 activity. Nevertheless, in our knock-in mouse model expressing CUL3(Δ403-459) we could not show any alteration in ROMK expression by either western blotting whole kidney lysates or confocal microscopy of kidney sections. This suggests that the hyperkalemia in our knock-in mouse and human PHA2E subjects with the CUL3(Δ403-459) mutation is not caused by reduced ROMK expression in the distal nephron.
British Heart Foundation. Grant Number: PG/13/89/30577
This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.14814/phy2.12850
Databáze: OpenAIRE
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