Publication Date:
2022-05-25
Description:
© The Author(s), 2012. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Cell Reports 2 (2012): 242–248, doi:10.1016/j.celrep.2012.06.016.
Description:
Ion selectivity of metazoan voltage-gated Na+ channels is critical for neuronal signaling and has long been attributed to a ring of four conserved amino acids that constitute the ion selectivity filter (SF) at the channel pore. Yet, in addition to channels with a preference for Ca2+ ions, the expression and characterization of Na+ channel homologs from the sea anemone Nematostella vectensis, a member of the early-branching metazoan phylum Cnidaria, revealed a sodium-selective channel bearing a noncanonical SF. Mutagenesis and physiological assays suggest that pore elements additional to the SF determine the preference for Na+ in this channel. Phylogenetic analysis assigns the Nematostella Na+-selective channel to a channel group unique to Cnidaria, which diverged 〉540 million years ago from Ca2+-conducting Na+ channel homologs. The identification of Cnidarian Na+-selective ion channels distinct from the channels of bilaterian animals indicates that selectivity for Na+ in neuronal signaling emerged independently in these two animal lineages.
Description:
This study was supported by
a research grant from the Austrian National Science Foundation (FWF P
21108-B17) to U.T., and by a United States-Israel Binational Agricultural Research and Development Grant (IS-4313-10) and an Israeli Science Foundation
grant (107/08) to M.G.
Repository Name:
Woods Hole Open Access Server
Type:
Article
Format:
application/pdf
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