Major diversification of voltage-gated K+ channels occurred in ancestral parahoxozoans.

摘要: We examined the origins and functional evolution of Shaker KCNQ families voltage-gated K+ channels to better understand how neuronal excitability evolved. In bilaterians, family consists four functionally distinct gene (Shaker, Shab, Shal, Shaw) that share a subunit structure consisting channel motif coupled cytoplasmic domain mediates subfamily-exclusive assembly (T1). traced origin this unique common ancestor ctenophores parahoxozoans (cnidarians, placozoans). Thus, is metazoan specific but likely have evolved in basal metazoan. Phylogenetic analysis suggested subfamily could predate divergence parahoxozoans, Shaw subfamilies are parahoxozoan specific. support this, putative ctenophore subunits coassembled with cnidarian mouse subunits, not or subunits. The family, which has structure, also appears solely within lineage. Functional indicated characteristic properties Shaker, Shaw, currents before cnidarians bilaterians. These results show major diversification occurred ancestral imply many fundamental mechanisms for regulation action potential propagation at time. Our further suggest there be substantial differences between parahoxozoans.