Journal of Membrane Biology

, Volume 234, Issue 2, pp 125–135

Nonenzymatic Augmentation of Lactate Transport via Monocarboxylate Transporter Isoform 4 by Carbonic Anhydrase II

  • Holger M. Becker
  • Michael Klier
  • Joachim W. Deitmer
Article

DOI: 10.1007/s00232-010-9240-y

Cite this article as:
Becker, H.M., Klier, M. & Deitmer, J.W. J Membrane Biol (2010) 234: 125. doi:10.1007/s00232-010-9240-y

Abstract

Monocarboxylate transporters (MCTs) are carriers of high-energy metabolites like lactate and pyruvate, and different MCT isoforms are expressed in a wide range of cells and tissues. Transport activity of MCT isoform 1 (MCT1), heterologously expressed in Xenopus oocytes, has previously been shown to be supported by carbonic anhydrase II (CAII) in a noncatalytic manner. In the present study, we investigated possible interactions of CAII with MCT4, expressed in Xenopus oocytes. MCT4 transport activity is enhanced both by injected and by coexpressed CAII, similar to MCT1, with the highest augmentation at low extracellular pH and low lactate concentrations. CAII-induced augmentation in MCT4 transport activity is independent from the enzyme’s catalytic function, as shown by application of the CA inhibitor ethoxyzolamide and by coexpression of MCT4 with the catalytically inactive mutant CAII-V143Y.

Keywords

Membrane transport mechanism Ion transport Electrophysiology Xenopus oocytes 

Copyright information

© Springer Science+Business Media, LLC 2010

Authors and Affiliations

  • Holger M. Becker
    • 1
  • Michael Klier
    • 2
  • Joachim W. Deitmer
    • 2
  1. 1.Arbeitsgruppe Zoologie/MembrantransportFB Biologie, TU KaiserslauternKaiserslauternGermany
  2. 2.Abteilung für Allgemeine ZoologieFB Biologie, TU KaiserslauternKaiserslauternGermany

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