Endosomal Chloride-Proton Exchange Rather Than Chloride Conductance Is Crucial for Renal Endocytosis
Abstract
Loss of the endosomal anion transport protein ClC-5 impairs renal endocytosis and underlies human Dent’s disease. ClC-5 is thought to promote endocytosis by facilitating endosomal acidification through the neutralization of proton pump currents. However, ClC-5 is a 2 chloride (Cl-)/proton (/H+) exchanger rather than a Cl- channel. We generated mice that carry the uncoupling E211A (unc) mutation that converts ClC-5 into a pure Cl- conductor. Adenosine triphosphate (ATP)-dependent acidification of renal endosomes was reduced in mice in which ClC-5 was knocked out, but normal in Clcn5unc mice. However, their proximal tubular endocytosis was also impaired. Thus, endosomal chloride concentration, which is raised by ClC-5 in exchange for protons accumulated by the H+-ATPase, may play a role in endocytosis.
- Publication:
-
Science
- Pub Date:
- June 2010
- DOI:
- 10.1126/science.1188070
- Bibcode:
- 2010Sci...328.1398N
- Keywords:
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- CELL BIOL