Preferential KAT1-KAT2 heteromerization determines inward K+ current properties in Arabidopsis guard cells.

Archive ouverte

Lebaudy, Anne | Pascaud, François | Véry, Anne-Aliénor | Alcon, Carine | Dreyer, Ingo | Thibaud, Jean-Baptiste | Lacombe, Benoît

Edité par CCSD ; American Society for Biochemistry and Molecular Biology -

International audience. Guard cells adjust their volume by changing their ion content due to intense fluxes that, for K(+), are believed to flow through inward or outward Shaker channels. Because Shaker channels can be homo- or heterotetramers and Arabidopsis guard cells express at least five genes encoding inward Shaker subunits, including the two major ones, KAT1 and KAT2, the molecular identity of inward Shaker channels operating therein is not yet completely elucidated. Here, we first addressed the properties of KAT1-KAT2 heteromers by expressing KAT1-KAT2 tandems in Xenopus oocytes. Then, computer analyses of the data suggested that coexpression of free KAT1 and KAT2 subunits resulted mainly in heteromeric channels made of two subunits of each type due to some preferential association of KAT1-KAT2 heterodimers at the first step of channel assembly. This was further supported by the analysis of KAT2 effect on KAT1 targeting in tobacco cells. Finally, patch-clamp recordings of native inward channels in wild-type and mutant genotypes strongly suggested that this preferential heteromerization occurs in planta and that Arabidopsis guard cell inward Shaker channels are mainly heteromers of KAT1 and KAT2 subunits.

Suggestions

Du même auteur

Calcium-dependent modulation and plasma membrane targeting of the AKT2 potassium channel by the CBL4/CIPK6 calcium sensor/protein kinase complex.

Archive ouverte | Held, Katrin | CCSD

International audience. Potassium (K(+)) channel function is fundamental to many physiological processes. However, components and mechanisms regulating the activity of plant K(+) channels remain poorly understood. H...

Plant adaptation to fluctuating environment and biomass production are strongly dependent on guard cell potassium channels

Archive ouverte | Lebaudy, Anne | CCSD

At least four genes encoding plasma membrane inward K+ channels (Kin channels) are expressed in Arabidopsis guard cells. A double mutant plant was engineered by disruption of a major Kin channel gene and expression of a dominant n...

Increased functional diversity of plant K+ channels by preferential heteromerization of the shaker-like subunits AKT2 and KAT2.

Archive ouverte | Xicluna, Jérôme | CCSD

CD-BPMP PUBLICATIONS 2007. Assembly of plant Shaker subunits as heterotetramers, increasing channel functional diversity, has been reported. Here we focus on a new interaction, between AKT2 and KAT2 subunits. The as...

Chargement des enrichissements...