Publikationsdatenbank

Human gene SLC41A1 encodes for the Na+/Mg²+ exchanger (2012)

Art

Zeitschriftenartikel / wissenschaftlicher Beitrag

Autoren

Kolisek, Martin

Nestler, Axel

Vormann, Jürgen

Schweigel-Röntgen, Monika

Quelle

American journal of physiology / Cell physiology; 302(1) — S. C318–C326

ISSN: 0363-6143

Sprache

Englisch

Verweise

DOI: 10.1152/ajpcell.00289.2011

Pubmed: 22031603

Kontakt

Institut für Veterinär-Physiologie

Oertzenweg 19 b
14163 Berlin
+49 30 838 62600
physiologie@vetmed.fu-berlin.de

Abstract / Zusammenfassung

Magnesium (Mg(2+)), the second most abundant divalent intracellular cation, is involved in the vast majority of intracellular processes, including the synthesis of nucleic acids, proteins, and energy metabolism. The concentration of intracellular free Mg(2+) ([Mg(2+)](i)) in mammalian cells is therefore tightly regulated to its optimum, mainly by an exchange of intracellular Mg(2+) for extracellular Na(+). Despite the importance of this process for cellular Mg(2+) homeostasis, the gene(s) encoding for the functional Na(+)/Mg(2+) exchanger is (are) still unknown. Here, using the fluorescent probe mag-fura 2 to measure [Mg(2+)](i) changes, we examine Mg(2+) extrusion from hSLC41A1-overexpressing human embryonic kidney (HEK)-293 cells. A three- to fourfold elevation of [Mg(2+)](i) was accompanied by a five- to ninefold increase of Mg(2+) efflux. The latter was strictly dependent on extracellular Na(+) and reduced by 91% after complete replacement of Na(+) with N-methyl-d-glucamine. Imipramine and quinidine, known unspecific Na(+)/Mg(2+) exchanger inhibitors, led to a strong 88% to 100% inhibition of hSLC41A1-related Mg(2+) extrusion. In addition, our data show regulation of the transport activity via phosphorylation by cAMP-dependent protein kinase A. As these are the typical characteristics of a Na(+)/Mg(2+) exchanger, we conclude that the human SLC41A1 gene encodes for the Na(+)/Mg(2+) exchanger, the predominant Mg(2+) efflux system. Based on this finding, the analysis of Na(+)/Mg(2+) exchanger regulation and its involvement in the pathogenesis of diseases such as Parkinson's disease and hypertension at the molecular level should now be possible.