ClC-5, the chloride channel mutated in Dent’s disease, colocalizes with the proton pump in endocytotically active kidney cells
AUTOR(ES)
Günther, Willy
FONTE
The National Academy of Sciences
RESUMO
Loss-of-function mutations of the ClC-5 chloride channel lead to Dent’s disease, a syndrome characterized by low molecular weight proteinuria, hypercalciuria, and kidney stones. We show that ClC-5 is expressed in renal proximal tubule cells, which normally endocytose proteins passing the glomerular filter. Expression is highest below the brush border in a region densely packed with endocytotic vesicles, where ClC-5 colocalizes with the H+-ATPase and with internalized proteins early after uptake. In intercalated cells of the collecting duct it again localizes to apical intracellular vesicles and colocalizes with the proton pump in α-intercalated cells. In transfected cells, ClC-5 colocalizes with endocytosed α2-macroglobulin. Cotransfection with a GTPase-deficient rab5 mutant leads to enlarged early endosomes that stain for ClC-5. We suggest that ClC-5 may be essential for proximal tubular endocytosis by providing an electrical shunt necessary for the efficient acidification of vesicles in the endocytotic pathway, explaining the proteinuria observed in Dent’s disease.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=20931Documentos Relacionados
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