%0 Journal Article
%T Regulation of Na+/K+ ATPase Transport Velocity by RNA Editing
%A Claudia Colina
%A Juan Pablo Palavicini
%A Deepa Srikumar
%A Miguel Holmgren
%A Joshua J. C. Rosenthal
%J PLOS Biology
%D 2010
%I Public Library of Science (PLoS)
%R 10.1371/journal.pbio.1000540
%X Because firing properties and metabolic rates vary widely, neurons require different transport rates from their Na+/K+ pumps in order to maintain ion homeostasis. In this study we show that Na+/K+ pump activity is tightly regulated by a novel process, RNA editing. Three codons within the squid Na+/K+ ATPase gene can be recoded at the RNA level, and the efficiency of conversion for each varies dramatically, and independently, between tissues. At one site, a highly conserved isoleucine in the seventh transmembrane span can be converted to a valine, a change that shifts the pump's intrinsic voltage dependence. Mechanistically, the removal of a single methyl group specifically targets the process of Na+ release to the extracellular solution, causing a higher turnover rate at the resting membrane potential.
%U http://www.plosmedicine.org/article/info%3Adoi%2F10.1371%2Fjournal.pbio.1000540