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Hyperkalemic hypertension-associated cullin 3 promotes WNK signaling by degrading KLHL3.

Authors :
McCormick, James A.
Chao-Ling Yang
Chong Zhang
Davidge, Brittney
Blankenstein, Katharina I.
Terker, Andrew S.
Yarbrough, Bethzaida
Meermeier, Nicholas P.
Park, Hae J.
McCully, Belinda
West, Mark
Borschewski, Aljona
Himmerkus, Nina
Bleich, Markus
Bachmann, Sebastian
Mutig, Kerim
Argaiz, Eduardo R.
Gamba, Gerardo
Singer, Jefrey D.
Ellison, David H.
Source :
Journal of Clinical Investigation. Nov2014, Vol. 124 Issue 11, p4723-4736. 14p. 2 Color Photographs, 3 Charts, 5 Graphs.
Publication Year :
2014

Abstract

Familial hyperkalemic hypertension (FHHt) is a monogenic disease resulting from mutations in genes encoding WNK kinases, the ubiquitin scafold protein cullin 3 (CUL3), or the substrate adaptor kelch-like 3 (KLHL3). Disease-associated CUL3 mutations abrogate WNK kinase degradation in cells, but it is not clear how mutant forms of CUL3 promote WNK stability. Here, we demonstrated that an FHHt-causing CUL3 mutant (CUL3 Δ403-459) not only retains the ability to bind and ubiquitylate WNK kinases and KLHL3 in cells, but is also more heavily neddylated and activated than WT CUL3. In cells, activated CUL3 Δ403-459 depleted KLHL3, preventing WNK degradation, despite increased CUL3-mediated WNK ubiquitylation; therefore, CUL3 loss in kidney should phenocopy FHHt in murine models. As predicted, nephron-specific deletion of Cul3 in mice did increase WNK kinase levels and the abundance of phosphorylated Na-Cl cotransporter (NCC). Over time, however, Cul3 deletion caused renal dysfunction, including hypochloremic alkalosis, diabetes insipidus, and salt-sensitive hypotension, with depletion of sodium potassium chloride cotransporter 2 and aquaporin 2. Moreover, these animals exhibited renal inflammation, fibrosis, and increased cyclin E. These results indicate that FHHt-associated CUL3 Δ403-459 targets KLHL3 for degradation, thereby preventing WNK degradation, whereas general loss of CUL3 activity -- while also impairing WNK degradation -- has widespread toxic effects in the kidney. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219738
Volume :
124
Issue :
11
Database :
Academic Search Index
Journal :
Journal of Clinical Investigation
Publication Type :
Academic Journal
Accession number :
99329856
Full Text :
https://doi.org/10.1172/JCI76126