Amino terminus and the first four membrane-spanning segments of the Arabidopsis K+ channel KAT1 confer inward-rectification property of plant-animal chimeric channels

49Citations
Citations of this article
12Readers
Mendeley users who have this article in their library.

This article is free to access.

Abstract

The Arabidopsis hyperpolarization-activated (inward-rectifying) K+ channel KAT1 is structurally more similar to animal depolarization-activated (outward-rectifying) K+ channels than to animal hyperpolarization-activated K+ channels. To gain insight into the structural basis for the opposite voltage dependences of plant inward-rectifying and animal outward-rectifying K+ channels, we constructed recombinant chimeric channels between the hyperpolarization-activated K+ channel KAT1 and a Xenopus depolarization-activated K+ channel. We report here that two of the chimeric constructs, which contain the first third of the KAT1 sequence, including the first four membrane-spanning segments (S1-S4) and the linker sequence between the fourth and fifth membrane-spanning segments, express functional channels that retain activation by hyperpolarization, but not depolarization. These two chimeric channels are no longer selective for K+. The chimeras are selective for cations over anions and are permeable to Ca2+. Therefore, unlike animal hyperpolarization-activated K+ channels, in which the carboxyl terminus is important for inward rectification induced by Mg2+ and polyamine block, the plant KAT1 channel has its major determinants for inward rectification in the amino-terminal region, which ends at the end of the S4-S5 linker.

Cite

CITATION STYLE

APA

Cao, Y., Crawford, N. M., & Schroeder, J. I. (1995). Amino terminus and the first four membrane-spanning segments of the Arabidopsis K+ channel KAT1 confer inward-rectification property of plant-animal chimeric channels. Journal of Biological Chemistry, 270(30), 17697–17701. https://doi.org/10.1074/jbc.270.30.17697

Register to see more suggestions

Mendeley helps you to discover research relevant for your work.

Already have an account?

Save time finding and organizing research with Mendeley

Sign up for free