Convergent evolution of sodium ion selectivity in metazoan neuronal signaling

Thumbnail Image
Date
2012-08-30
Authors
Barzilai, Maya Gur
Reitzel, Adam M.
Kraus, Johanna E. M.
Gordon, Dalia
Technau, Ulrich
Gurevitz, Michael
Moran, Yehu
Alternative Title
Date Created
Location
DOI
10.1016/j.celrep.2012.06.016
Replaced By
Keywords
Abstract
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
© 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.
Embargo Date
Citation
Cell Reports 2 (2012): 242–248
Cruises
Cruise ID
Cruise DOI
Vessel Name
Collections
Except where otherwise noted, this item's license is described as Attribution-NonCommercial-NoDerivs 3.0 Unported