Expression of a poriferan potassium channel: insights into the evolution of ion channels in metazoans.

ABSTRACT: Ion channels establish and regulate membrane potentials in excitable and non-excitable cells. How functional diversification of ion channels contributed to the evolution of nervous systems may be understood by studying organisms at key positions in the evolution of animal multicellularity. We have carried out the first analysis of ion channels cloned from a marine sponge, Amphimedon queenslandica. Phylogenetic comparison of sequences encoding for poriferan inward-rectifier K(+) (Kir) channels suggests that Kir channels from sponges, cnidarians and triploblastic metazoans each arose from a single channel and that duplications arose independently in the different groups. In Xenopus oocytes, AmqKirA and AmqKirB produced K(+) currents with strong inward rectification, as seen in the mammalian

SUBMITTER: Tompkins-Macdonald GJ 

PROVIDER: S-EPMC6518305 | biostudies-literature | 2009 Mar

REPOSITORIES: biostudies-literature