Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-16583
Biophys J 1997 May 01;725:2143-50.
Show Gene links Show Anatomy links

Plant K+ channel alpha-subunits assemble indiscriminately.

Dreyer I , Antunes S , Hoshi T , Müller-Röber B , Palme K , Pongs O , Reintanz B , Hedrich R .


???displayArticle.abstract???
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 alpha-subunits. cRNA encoding five different K+ channel alpha-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 alpha-subunits, functional aggregates of plant K(in) channel alpha-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 alpha-subunits, and thus depends on the spatial segregation of individual alpha-subunit pools and the degree of temporal overlap and kinetics of expression.

???displayArticle.pubmedLink??? 9129816
???displayArticle.pmcLink??? PMC1184408
???displayArticle.link??? Biophys J
???displayArticle.grants??? [+]

Species referenced: Xenopus
Genes referenced: akt1 kyat1

References [+] :
Anderson, Functional expression of a probable Arabidopsis thaliana potassium channel in Saccharomyces cerevisiae. 1992, Pubmed