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 similar to 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.
The voltage-sensing domain of a phosphatase gates the pore of a potassium channel / C. Arrigoni, I. Schroeder, G. Romani, J.L. Van Etten, G. Thiel, A. Moroni. - In: JOURNAL OF GENERAL PHYSIOLOGY. - ISSN 0022-1295. - 141:3(2013 Mar), pp. 389-395. [10.1085/jgp.201210940]
The voltage-sensing domain of a phosphatase gates the pore of a potassium channel
C. ArrigoniPrimo
;I. SchroederSecondo
;A. MoroniUltimo
2013
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 similar to 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.File | Dimensione | Formato | |
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