The arabidopsis R-SNARE VAMP721 interacts with KAT1 and KC1 K+ channels to moderate K+ current at the plasma membrane

Zhang, B. , Karnik, R. , Wang, Y., Wallmeroth, N., Blatt, M. R. and Grefen, C. (2015) The arabidopsis R-SNARE VAMP721 interacts with KAT1 and KC1 K+ channels to moderate K+ current at the plasma membrane. Plant Cell, 27(6), pp. 1697-1717. (doi:10.1105/tpc.15.00305) (PMID:26002867) (PMCID:PMC4498211)

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Publisher's URL: http://www.plantcell.org/content/early/2015/05/22/tpc.15.00305.abstract

Abstract

SNARE (soluble N-ethylmaleimide-sensitive factor protein attachment protein receptor) proteins drive vesicle traffic, delivering membrane and cargo to target sites within the cell and at its surface. They contribute to cell homeostasis, morphogenesis, and pathogen defense. A subset of SNAREs, including the Arabidopsis thaliana SNARE SYP121, are known also to coordinate solute uptake via physical interactions with K+ channels and to moderate their gating at the plasma membrane. Here, we identify a second subset of SNAREs that interact to control these K+ channels, but with opposing actions on gating. We show that VAMPs (vesicle-associated membrane proteins), which target vesicles to the plasma membrane, also interact with and suppress the activities of the inward-rectifying K+ channels KAT1 and KC1. Interactions were evident in yeast split-ubiquitin assays, they were recovered in vivo by ratiometric bimolecular fluorescence complementation, and they were sensitive to mutation of a single residue, Tyr-57, within the longin domain of VAMP721. Interaction was also recovered on exchange of the residue at this site in the homolog VAMP723, which normally localizes to the endoplasmic reticulum and otherwise did not interact. Functional analysis showed reduced channel activity and alterations in voltage sensitivity that are best explained by a physical interaction with the channel gates. These actions complement those of SYP121, a cognate SNARE partner of VAMP721, and lead us to propose that the channel interactions reflect a “hand-off” in channel control between the two SNARE proteins that is woven together with vesicle fusion.

Item Type:Articles
Status:Published
Refereed:Yes
Glasgow Author(s) Enlighten ID:Blatt, Professor Michael and Zhang, Dr Ben and Wang, Dr Yizhou and Grefen, Dr Christopher and Karnik, Dr Rucha
Authors: Zhang, B., Karnik, R., Wang, Y., Wallmeroth, N., Blatt, M. R., and Grefen, C.
College/School:College of Medical Veterinary and Life Sciences > Institute of Molecular Cell and Systems Biology
Journal Name:Plant Cell
Publisher:American Society of Plant Biologists
ISSN:1040-4651
ISSN (Online):1532-298X
Copyright Holders:Copyright © 2015 American Society of Plant Biologists
First Published:First published in Plant Cell 27(6):1697-1717
Publisher Policy:Reproduced under a Creative Commons License

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Project CodeAward NoProject NamePrincipal InvestigatorFunder's NameFunder RefLead Dept
563751MAGIC - A Multi-tiered approach to generating increased carbon dioxide in the chloroplastMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/I024496/1RI MOLECULAR CELL & SYSTEMS BIOLOGY
616991Directed control of secretory vesicle fusionMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/K015893/1RI MOLECULAR CELL & SYSTEMS BIOLOGY
626121Stomatal-based systems analysis of water use efficiencyMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/L001276/1RI MOLECULAR CELL & SYSTEMS BIOLOGY
563753MAGIC - A Multi-tiered approach to generating increased carbon dioxide in the chloroplastMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/M01133X/1RI MOLECULAR CELL & SYSTEMS BIOLOGY
537651Regulation of membrane fusion by a novel Sec1/Munc18-associated proteinMichael BlattBiotechnology and Biological Sciences Research Council (BBSRC)BB/H024867/1RI MOLECULAR CELL & SYSTEMS BIOLOGY