title: The voltage-sensing domain of a phosphatase gates the pore of a potassium channel.
abstract: The modular architecture of voltage-gated K(+) (Kv) channels suggests that they resulted from the fusion of a voltage-sensing domain (VSD) to a pore module. Here, we show that the VSD of Ciona intestinalis phosphatase (Ci-VSP) fused to the viral channel Kcv creates Kv(Synth1), a functional voltage-gated, outwardly rectifying K(+) channel. Kv(Synth1) displays the summed features of its individual components: pore properties of Kcv (selectivity and filter gating) and voltage dependence of Ci-VSP (V(1/2) = +56 mV; z of ~1), including the depolarization-induced mode shift. The degree of outward rectification of the channel is critically dependent on the length of the linker more than on its amino acid composition. This highlights a mechanistic role of the linker in transmitting the movement of the sensor to the pore and shows that electromechanical coupling can occur without coevolution of the two domains.
authors: Department of Biosciences, Consiglio Nazionale delle Ricerche, Università degli Studi di Milano, 20133 Milano, Italy.
authors: Cristina
authors: C
authors: Arrigoni
authors: Indra
authors: I
authors: Schroeder
authors: Giulia
authors: G
authors: Romani
authors: James L
authors: JL
authors: Van Etten
authors: Gerhard
authors: G
authors: Thiel
authors: Anna
authors: A
authors: Moroni
mesh_terms: D000818:Animals; D002938:Ciona intestinalis / Q000378:metabolism; D015640:Ion Channel Gating / Q000502:physiology*; D010539:Permeability; D010744:Phosphoric Monoester Hydrolases / Q000378:metabolism*; D024642:Potassium Channels, Voltage-Gated / Q000378:metabolism*; D017434:Protein Structure, Tertiary; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D014982:Xenopus laevis
chemical_list: D024642:Potassium Channels, Voltage-Gated; D011993:Recombinant Fusion Proteins; D010744:Phosphoric Monoester Hydrolases