CrossTalk opposing view: CNNM proteins are not Na+/Mg2+ exchangers but Mg2+ transport regulators playing a central role in transepithelial Mg2+ (re)absorption

نویسندگان

  • Francisco J Arjona
  • Jeroen H F de Baaij
چکیده

Magnesium (Mg2+) is indispensable for many physiological processes in the cell impacting organ function (de Baaij et al. 2015). Intracellular concentrations of free Mg2+ aremaintained within a narrow range (0.5–1.2 mM) through tightly regulated Mg2+ influx and effluxmechanisms (Ebel & Gunther, 1980). InhibitionofMg2+ effluxby substitution of extracellular Na+ by choline in mammalian cells indicates that Mg2+ extrusion is Na+ dependent (Guther et al. 1984). Thus, it is postulated that Mg2+ efflux occurs via a Na+/Mg2+ exchanger, this notion being corroborated in a large number of studies in different cell models (Romani, 2007). Under the premise that differential gene expression is involved in the maintenance of cellular Mg2+ homeostasis, microarray analyses in epithelial cells exposed to low extracellular Mg2+ concentrations have been classically used to designate proteins involved in Mg2+ transport (Quamme, 2010). One of the protein families identified with this approach is the CNNM family. CNNM proteins have been proposed to

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Rebuttal from Francisco J. Arjona and Jeroen H. F. de Baaij

We fully agree with Funato and colleagues on the relevance of CNNM proteins for the maintenance of Mg2+ homeostasis (Funato et al. 2018). Both of our papers summarize the solid body of evidence demonstrating thatCNNM2 is key for renalMg2+ handling, while CNNM4 regulates intestinal Mg2+ transport. Nevertheless, we do not share the conclusions presented by Funato and colleagues suggesting that CN...

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عنوان ژورنال:

دوره 596  شماره 

صفحات  -

تاریخ انتشار 2018