Intrarenal and subcellular localization of rat clc5. Luyckx, Valerie A., Fatime O. Goda, David B. Mount, Toshiyuki Nishio, Amy Hall, Steven C. Hebert, Timothy G. Hammond and Alan S. L. Yu. 1Renal Division, Department of Medicine, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02115, 2Nephrology Section, Tulane University Medical Center and New Orleans Veterans Administration Medical Center, New Orleans, Louisiana 70112, 3Division of Nephrology, Vanderbilt University Medical Center, Nashville, Tennessee 37232
APStracts 5:0130F, 1998.
Dent's disease, an inherited disorder characterized by hypercalciuria, nephrolithiasis, nephrocalcinosis, rickets, low molecular weight proteinuria, Fanconi's syndrome and renal failure, is caused by mutations in the renal chloride channel, CLC5. The normal role of CLC5 is unknown. We have investigated the intrarenal and subcellular localization of CLC5 in rat kidney by in situ hybridization and immunohistochemistry. By in situ hybridization, CLC5 mRNA was detected predominantly in cortical medullary ray and outer medullary tubule epithelial cells. Polyclonal antiserum was generated against a CLC5 fusion protein, affinity-purified, and immunoadsorbed against CLC3 and CLC4 to yield a CLC5 isoform-specific antiserum. By immunohistochemistry, CLC5 protein was localized to the intracellular domain of tubular epithelial cells in the S3 segment of the proximal tubule and the medullary thick ascending limb. By subcellular membrane fractionation and flow cytometry, CLC5 expression was found in outer medullary endosomes. These findings are consistent with a model in which CLC5 encodes an endosomal chloride channel that facilitates acidification and trafficking of renal epithelial endosomes. 

Received 22 December 1998; accepted in final form 22 July 1998.
APS Manuscript Number F404-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 21 September 1998