Molecular identification and functional characterization of rabbit MATE1 and MATE2-K

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

An electroneutral organic cation (OC)/proton exchanger in the apical membrane of proximal tubules mediates the final step of renal OC excretion. Two members of the multidrug and toxin extrusion family, MATE1 and MATE2-K, were recently identified in human and rodent kidney and proposed to be the molecular basis of renal OC/H+ exchange. To take advantage of the comparative value of the large database on the kinetic and selectivity characteristics of OC/H+ exchange that exists for rabbit kidney, we cloned rbMATE1 and rbMATE2-K. The rabbit homologs have 75% (MATE1) and 74% (MATE2-K) amino acid identity to their human counterparts (and 51% identity with each other). rbMATE1 and rbMATE2-K exhibited H+ gradient-dependent uptake and efflux of tetraethylammonium (TEA) when expressed in Chinese hamster ovary cells. Both transporters displayed similar affinities for selected compounds [IC 50 values within 2-fold for TEA, 1-methyl-4-phenylpyridinium, and quinidine] and very different affinities for others (IC50 values differing by 8- to 80-fold for choline and cimetidine, respectively). These results indicate that rbMATE1 and rbMATE2-K are multispecific OC/H+ exchangers with similar, but distinct, functional characteristics. Overall, the selectivity of MATE1 and MATE2-K correlated closely with that observed in rabbit renal brush-border membrane vesicles.

Original languageEnglish (US)
Pages (from-to)F360-F370
JournalAmerican Journal of Physiology - Renal Physiology
Volume293
Issue number1
DOIs
StatePublished - Jul 1 2007

Keywords

  • Kidney
  • Organic cation
  • Proximal tubule
  • Tetraethylammonium
  • Transport

ASJC Scopus subject areas

  • Physiology
  • Urology

Fingerprint Dive into the research topics of 'Molecular identification and functional characterization of rabbit MATE1 and MATE2-K'. Together they form a unique fingerprint.

  • Cite this