Modulation of Na+/H+ exchange activity by Cl-

Orit Aharonovitz, András Kapus, Katalin Szászi, Natasha Coady-Osberg, Timothy Jancelewicz, John Orlowski, Sergio Grinstein

Research output: Contribution to journalArticle

27 Citations (Scopus)

Abstract

Na+/H+ exchanger (NHE) activity is exquisitely dependent on the intra- and extracellular concentrations of Na+ and H+. In addition, Cl- ions have been suggested to modulate NHE activity, but little is known about the underlying mechanism, and the Cl- sensitivity of the individual isoforms has not been established. To explore their Cl- sensitivity, types 1, 2, and 3 Na+/H+ exchangers (NHE1, NHE2, and NHE3) were heterologously expressed in antiport-deficient cells. Bilateral replacement of Cl- with nitrate or thiocyanate inhibited the activity of all isoforms. Cl- depletion did not affect cell volume or the cellular ATP content, which could have indirectly altered NHE activity. The number of plasmalemmal exchangers was unaffected by Cl- removal, implying that inhibition was due to a decrease in the intrinsic activity of individual exchangers. Analysis of truncated mutants of NHE1 revealed that the anion sensitivity resides, at least in part, in the COOH-terminal domain of the exchanger. Moreover, readdition of Cl- into the extracellular medium failed to restore normal transport, suggesting that intracellular Cl- is critical for activity. Thus interaction of intracellular Cl- with the COOH terminus of NHE1 or with an associated protein is essential for optimal activity.

Original languageEnglish (US)
JournalAmerican Journal of Physiology - Cell Physiology
Volume281
Issue number1 50-1
StatePublished - Oct 16 2001
Externally publishedYes

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Sodium-Hydrogen Antiporter
Protein Isoforms
Ion Transport
Cell Size
Nitrates
Anions
Adenosine Triphosphate
Ions
Proteins

All Science Journal Classification (ASJC) codes

  • Physiology
  • Cell Biology

Cite this

Aharonovitz, O., Kapus, A., Szászi, K., Coady-Osberg, N., Jancelewicz, T., Orlowski, J., & Grinstein, S. (2001). Modulation of Na+/H+ exchange activity by Cl-. American Journal of Physiology - Cell Physiology, 281(1 50-1).

Modulation of Na+/H+ exchange activity by Cl-. / Aharonovitz, Orit; Kapus, András; Szászi, Katalin; Coady-Osberg, Natasha; Jancelewicz, Timothy; Orlowski, John; Grinstein, Sergio.

In: American Journal of Physiology - Cell Physiology, Vol. 281, No. 1 50-1, 16.10.2001.

Research output: Contribution to journalArticle

Aharonovitz, O, Kapus, A, Szászi, K, Coady-Osberg, N, Jancelewicz, T, Orlowski, J & Grinstein, S 2001, 'Modulation of Na+/H+ exchange activity by Cl-', American Journal of Physiology - Cell Physiology, vol. 281, no. 1 50-1.
Aharonovitz O, Kapus A, Szászi K, Coady-Osberg N, Jancelewicz T, Orlowski J et al. Modulation of Na+/H+ exchange activity by Cl-. American Journal of Physiology - Cell Physiology. 2001 Oct 16;281(1 50-1).
Aharonovitz, Orit ; Kapus, András ; Szászi, Katalin ; Coady-Osberg, Natasha ; Jancelewicz, Timothy ; Orlowski, John ; Grinstein, Sergio. / Modulation of Na+/H+ exchange activity by Cl-. In: American Journal of Physiology - Cell Physiology. 2001 ; Vol. 281, No. 1 50-1.
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