Plant K+ channel α-subunits assemble indiscriminately

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


In plants a large diversity of inwardly rectifying K+ channels (K(in) channels) has been observed between tissues and species. However, only three different types of voltage-dependent plant K+ uptake channel subfamilies have been cloned so far; they relate either to KAT1, AKT1, or AtKC1. To explore the mechanisms underlying the channel diversity, we investigated the assembly of plant inwardly rectifying α-subunits. cRNA encoding five different K+ channel α-subunits of the three subfamilies (KAT1, KST1, AKT1, SKT1, and AtKC1) which were isolated from different tissues, species, and plant families (Arabidopsis thaliana and Solanum tuberosum) was reciprocally co-injected into Xenopus oocytes. We identified plant K+ channels as multimers. Moreover, using K+ channel mutants expressing different sensitivities to voltage, Cs+, Ca2+, and H+, we could prove heteromers on the basis of their altered voltage and modulator susceptibility. We discovered that, in contrast to animal K+ channel α-subunits, functional aggregates of plant K(in) channel α-subunits assembled indiscriminately. Interestingly, AKT-type channels from A. thaliana and S. tuberosum, which as homomers were electrically silent in oocytes after co-expression, mediated K+ currents. Our findings suggest that K+ channel diversity in plants results from nonselective heteromerization of different α-subunits, and thus depends on the spatial segregation of individual α-subunit pools and the degree of temporal overlap and kinetics of expression.




Dreyer, I., Antunes, S., Hoshi, T., Müller-Röber, B., Palme, K., Pongs, O., … Hedrich, R. (1997). Plant K+ channel α-subunits assemble indiscriminately. Biophysical Journal, 72(5), 2143–2150.

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