Association of plant K+ in channels is mediated by conserved C‐termini and does not affect subunit assembly

FEBS Letters

Ehrhardt, Thomas¹  Zimmermann, Sabine¹  Müller-Röber, Bernd¹ 

[1] Max-Planck-Institut für Molekulare Pflanzenphysiologie (MPI-MOPP), Karl-Liebknecht-Straße 25, Haus 20, D-14476 Golm, Potsdam, Germany

关键词: Guard cell;    Insect cell;    Potassium channel;    Two-hybrid system;    Potato;    K+;    potassium;    GFP;    green fluorescence protein;    Bait;    protein fusion to Gal4-binding domain;    Prey;    protein fusion to Gal4 activation domain;   

DOI  :  10.1016/S0014-5793(97)00502-4

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Inward rectifying potassium (K⁺ _in) channels play an important role in turgor regulation and ion uptake in higher plants. Here, we report a previously unrecognized feature of these proteins: K⁺ _in channel C-terminal polypeptides mediate channel protein interactions. Using a C-terminal fragment of potato guard cell K⁺ _in channel KST1 in a yeast two-hybrid screen two novel putative K⁺ _in channel proteins (SKT2 and SKT3) were identified by interaction of their C-termini which contained a conserved domain (K_HA). Interactions were confirmed by Western blot-related assays utilizing K⁺ _in channel C-termini fused to green fluorescence protein. Although deletion of the K_HA-domain abolished these interactions, K⁺ _in currents were still detectable by patch-clamp measurements of insect cells expressing these KST1 mutants, indicating that formation of a functional channel does not depend on this C-terminal domain.

【 授权许可】

Unknown