title: Phylogeny unites animal sodium leak channels with fungal calcium channels in an ancient, voltage-insensitive clade.
abstract: Proteins in the superfamily of voltage-gated ion channels mediate behavior across the tree of life. These proteins regulate the movement of ions across cell membranes by opening and closing a central pore that controls ion flow. The best-known members of this superfamily are the voltage-gated potassium, calcium (Ca(v)), and sodium (Na(v)) channels, which underlie impulse conduction in nerve and muscle. Not all members of this family are opened by changes in voltage, however. NALCN (NA(+) leak channel nonselective) channels, which encode a voltage-insensitive "sodium leak" channel, have garnered a growing interest. This study examines the phylogenetic relationship among Na(v)/Ca(v) voltage-gated and voltage-insensitive channels in the eukaryotic group Opisthokonta, which includes animals, fungi, and their unicellular relatives. We show that NALCN channels diverged from voltage-gated channels before the divergence of fungi and animals and that the closest relatives of NALCN channels are fungal calcium channels, which they functionally resemble.
authors: Section of Integrative Biology and Center for Computational Biology and Bioinformatics, University of Texas, USA. bliebeskind@austin.utexas.edu
authors: Benjamin J
authors: BJ
authors: Liebeskind
authors: David M
authors: DM
authors: Hillis
authors: Harold H
authors: HH
authors: Zakon
mesh_terms: D000818:Animals; D001499:Bayes Theorem; D019143:Evolution, Molecular; D005658:Fungi / Q000235:genetics*; D007448:Invertebrates / Q000235:genetics*; D007473:Ion Channels / Q000235:genetics*; D016013:Likelihood Functions; D008565:Membrane Proteins; D008957:Models, Genetic; D010802:Phylogeny; D015222:Sodium Channels / Q000235:genetics
chemical_list: D007473:Ion Channels; D008565:Membrane Proteins; C544681:NALCN protein, human; D015222:Sodium Channels