| Autor: |
Nina Milosavljevic, Michaël Monet, Isabelle Léna, Frédéric Brau, Sandra Lacas-Gervais, Sylvain Feliciangeli, Laurent Counillon, Mallorie Poët |
| Jazyk: |
angličtina |
| Rok vydání: |
2014 |
| Předmět: |
|
| Zdroj: |
Cell Reports, Vol 7, Iss 3, Pp 689-696 (2014) |
| Druh dokumentu: |
article |
| ISSN: |
2211-1247 |
| DOI: |
10.1016/j.celrep.2014.03.054 |
| Popis: |
Vesicular H+-ATPases and ClC-chloride transporters are described to acidify intracellular compartments, which also express the highly conserved Na+/H+ exchangers NHE6, NHE7, and NHE9. Mutations of these exchangers cause autism-spectrum disorders and neurodegeneration. NHE6, NHE7, and NHE9 are hypothesized to exchange cytosolic K+ for H+ and alkalinize vesicles, but this notion has remained untested in K+ because their intracellular localization prevents functional measurements. Using proton-killing techniques, we selected a cell line that expresses wild-type NHE7 at the plasma membrane, enabling measurement of the exchanger’s transport parameters. We found that NHE7 transports Li+ and Na+, but not K+, is nonreversible in physiological conditions and is constitutively activated by cytosolic H+. Therefore, NHE7 acts as a proton-loading transporter rather than a proton leak. NHE7 mediates an acidification of intracellular vesicles that is additive to that of V-ATPases and that accelerates endocytosis. This study reveals an unexpected function for vesicular Na+/H+ exchangers and provides clues for understanding NHE-linked neurological disorders. |
| Databáze: |
Directory of Open Access Journals |
| Externí odkaz: |
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