A novel CLCN5 pathogenic mutation supports Dent disease with normal endosomal acidification.
Hum Mutat
; 39(8): 1139-1149, 2018 08.
Article
en En
| MEDLINE
| ID: mdl-29791050
ABSTRACT
Dent disease is an X-linked recessive renal tubular disorder characterized by low-molecular-weight proteinuria, hypercalciuria, nephrolithiasis, nephrocalcinosis, and progressive renal failure. Inactivating mutations of CLCN5, the gene encoding the 2Cl- /H+ exchanger ClC-5, have been reported in patients with Dent disease 1. In vivo studies in mice harboring an artificial mutation in the "gating glutamate" of ClC-5 (c.632A > C, p.Glu211Ala) and mathematical modeling suggest that endosomal chloride concentration could be an important parameter in endocytosis, rather than acidification as earlier hypothesized. Here, we described a novel pathogenic mutation affecting the "gating glutamate" of ClC-5 (c.632A>G, p.Glu211Gly) and investigated its molecular consequences. In HEK293T cells, the p.Glu211Gly ClC-5 mutant displayed unaltered N-glycosylation and normal plasma membrane and early endosomes localizations. In Xenopus laevis oocytes and HEK293T cells, we found that contrasting with wild-type ClC-5, the mutation abolished the outward rectification, the sensitivity to extracellular H+ and converted ClC-5 into a Cl- channel. Investigation of endosomal acidification in HEK293T cells using the pH-sensitive pHluorin2 probe showed that the luminal pH of cells expressing a wild-type or p.Glu211Gly ClC-5 was not significantly different. Our study further confirms that impaired acidification of endosomes is not the only parameter leading to defective endocytosis in Dent disease 1.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Banco de datos:
MEDLINE
Asunto principal:
Endosomas
/
Canales de Cloruro
/
Mutación
Límite:
Animals
/
Humans
Idioma:
En
Revista:
Hum Mutat
Asunto de la revista:
GENETICA MEDICA
Año:
2018
Tipo del documento:
Article
País de afiliación:
Francia