32176
2010
2010
eng
article
1
--
--
--
A minimal cysteine motif required to activate the SKOR K+ channel of Arabidopsis by the reactive oxygen species H2O2
Reactive oxygen species (ROS) are essential for development and stress signaling in plants. They contribute to plant defense against pathogens, regulate stomatal transpiration, and influence nutrient uptake and partitioning. Although both Ca2+ and K+ channels of plants are known to be affected, virtually nothing is known of the targets for ROS at a molecular level. Here we report that a single cysteine (Cys) residue within the Kv-like SKOR K+ channel of Arabidopsis thaliana is essential for channel sensitivity to the ROS H2O2. We show that H2O2 rapidly enhanced current amplitude and activation kinetics of heterologously expressed SKOR, and the effects were reversed by the reducing agent dithiothreitol (DTT). Both H2O2 and DTT were active at the outer face of the membrane and current enhancement was strongly dependent on membrane depolarization, consistent with a H2O2-sensitive site on the SKOR protein that is exposed to the outside when the channel is in the open conformation. Cys substitutions identified a single residue, Cys(168) located within the S3 alpha-helix of the voltage sensor complex, to be essential for sensitivity to H2O2. The same Cys residue was a primary determinant for current block by covalent Cys S-methioylation with aqueous methanethiosulfonates. These, and additional data identify Cys168 as a critical target for H2O2, and implicate ROS-mediated control of the K+ channel in regulating mineral nutrient partitioning within the plant.
http://www.jbc.org/
10.1074/jbc.M110.141176
0021-9258
allegro:1991-2014
10108530
Journal of biological chemistry. - ISSN 0021-9258. - 285 (2010), 38, S. 29286 - 29294
Carlos Garcia-Mata
Jianwen Wang
Pawel Gajdanowicz
Wendy Gonzalez
Adrian Hills
Naomi Donald
Janin Riedelsberger
Anna Amtmann
Ingo Dreyer
Michael R. Blatt
Institut für Biochemie und Biologie
Referiert
33987
2013
2013
eng
105 S.
doctoralthesis
Potsdam
1
--
--
--
Functional diversity of plant Shaker-like K+ channels and their regulation
allegro:1991-2014
10111028
Potsdam, Univ., Diss., 2013
Janin Riedelsberger
Institut für Biochemie und Biologie
38603
2015
2015
eng
17
9
10
article
PLoS
San Fransisco
1
--
--
--
Outward Rectification of Voltage-Gated K+ Channels Evolved at Least Twice in Life History
Voltage-gated potassium (K+) channels are present in all living systems. Despite high structural similarities in the transmembrane domains (TMD), this K+ channel type segregates into at least two main functional categories-hyperpolarization-activated, inward-rectifying (Kin) and depolarization-activated, outward-rectifying (Kout) channels. Voltage-gated K+ channels sense the membrane voltage via a voltage-sensing domain that is connected to the conduction pathway of the channel. It has been shown that the voltage-sensing mechanism is the same in Kin and Kout channels, but its performance results in opposite pore conformations. It is not known how the different coupling of voltage-sensor and pore is implemented. Here, we studied sequence and structural data of voltage-gated K+ channels from animals and plants with emphasis on the property of opposite rectification. We identified structural hotspots that alone allow already the distinction between Kin and Kout channels. Among them is a loop between TMD S5 and the pore that is very short in animal Kout, longer in plant and animal Kin and the longest in plant Kout channels. In combination with further structural and phylogenetic analyses this finding suggests that outward-rectification evolved twice and independently in the animal and plant kingdom.
PLoS one
10.1371/journal.pone.0137600
26356684
1932-6203
wos:2015
e0137600
WOS:000360965800068
Riedelsberger, J (reprint author), Univ Talca, CBSM, Talca, Chile., jriedelsberger@utalca.cl; idreyer@utalca.cl
Chilean Fondo Nacional de Desarrollo Cientifico y Tecnologico [3150173, 1140624]; Chilean Comision Nacional de Investigacion Cientifica y Tecnologica [Anillo ACT-1104]; Deutsche Forschungsgemeinschaft [DR430/8-1]; Marie Curie Career Integration Grant of the European Union [303674-Regopoc]
<a href="http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-409594">Zweitveröffentlichung in der Schriftenreihe Postprints der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe ; 521</a>
Janin Riedelsberger
Ingo Dreyer
Wendy Gonzalez
Institut für Biochemie und Biologie
Referiert
Open Access
36128
2012
2012
eng
57
63
7
7
442
article
Portland Press
London
1
--
--
--
The pH sensor of the plant K+-uptake channel KAT1 is built from a sensory cloud rather than from single key amino acids
The uptake of potassium ions (K+) accompanied by an acidification of the apoplasm is a prerequisite for stomatal opening. The acidification (approximately 2-2.5 pH units) is perceived by voltage-gated inward potassium channels (K-in) that then can open their pores with lower energy cost. The sensory units for extracellular pH in stomatal K-in channels are proposed to be histidines exposed to the apoplasm. However, in the Arabidopsis thaliana stomatal K-in channel KAT1, mutations in the unique histidine exposed to the solvent (His(267)) do not affect the pH dependency. We demonstrate in the present study that His(267) of the KAT1 channel cannot sense pH changes since the neighbouring residue Phe(266) shifts its pK(a) to undetectable values through a cation-pi interaction. Instead, we show that Glu(240) placed in the extracellular loop between transmembrane segments S5 and S6 is involved in the extracellular acid activation mechanism. Based on structural models we propose that this region may serve as a molecular link between the pH- and the voltage-sensor. Like Glu(240), several other titratable residues could contribute to the pH-sensor of KAT1, interact with each other and even connect such residues far away from the voltage-sensor with the gating machinery of the channel.
The biochemical journal
10.1042/BJ20111498
0264-6021
wos:2011-2013
WOS:000300478700006
Gonzalez, W (reprint author), Univ Talca, Ctr Bioinformat & Simulac Mol, 2 Norte 685, Talca 3465548, Chile., wgonzalez@utalca.cl; ingo.dreyer@upm.es
DAAD-CONICYT (Servicio Aleman de Intercambio Academico-Comision Nacional
de Investigacion Cientifica y Tecnologica); Fondo Nacional de Desarrollo
Cientifico y Tecnologico (Chile) [11100373]; Abate Molina Excellence
Award; Deutsche Forschungsgemeinschaft [DR 430/8]; Heisenberg
fellowship; Max-Planck Research School; CONICYT (Comision Nacional de
Investigacion Cientifica y Tecnologica)
Wendy Gonzalez
Janin Riedelsberger
Samuel E. Morales-Navarro
Julio Caballero
Jans H. Alzate-Morales
Fernando D. Gonzalez-Nilo
Ingo Dreyer
eng
uncontrolled
Arabidopsis thaliana
eng
uncontrolled
channel protein structure
eng
uncontrolled
channel protein-proton interaction
eng
uncontrolled
KAT1
eng
uncontrolled
pH regulation
eng
uncontrolled
potassium chanel
Institut für Biochemie und Biologie
Referiert
55185
2017
2017
eng
12
7
article
Nature Publishing Group
London
1
2017-03-16
2017-03-16
--
The receptor-like pseudokinase MRH1 interacts with the voltage-gated potassium channel AKT2
The potassium channel AKT2 plays important roles in phloem loading and unloading. It can operate as inward-rectifying channel that allows H+-ATPase-energized K+ uptake. Moreover, through reversible post-translational modifications it can also function as an open, K+-selective channel, which taps a ‘potassium battery’, providing additional energy for transmembrane transport processes. Knowledge about proteins involved in the regulation of the operational mode of AKT2 is very limited. Here, we employed a large-scale yeast two-hybrid screen in combination with fluorescence tagging and null-allele mutant phenotype analysis and identified the plasma membrane localized receptor-like kinase MRH1/MDIS2 (AT4G18640) as interaction partner of AKT2. The phenotype of the mrh1-1 knockout plant mirrors that of akt2 knockout plants in energy limiting conditions. Electrophysiological analyses showed that MRH1/MDIS2 failed to exert any functional regulation on AKT2. Using structural protein modeling approaches, we instead gathered evidence that the putative kinase domain of MRH1/MDIS2 lacks essential sites that are indispensable for a functional kinase suggesting that MRH1/MDIS2 is a pseudokinase. We propose that MRH1/MDIS2 and AKT2 are likely parts of a bigger protein complex. MRH1 might help to recruit other, so far unknown partners, which post-translationally regulate AKT2. Additionally, MRH1 might be involved in the recognition of chemical signals.
Scientific reports
10.1038/srep44611
28300158
2045-2322
wos:2017
44611
WOS:000396543900001
Riedelsberger, J (reprint author), Univ Talca, Fac Ingn, Ctr Bioinform & Simulac Mol, Talca, Chile., jriedelsberger@utalca.cl; idreyer@utalca.cl
Fonds der Chemischen Industrie
2022-06-15T10:40:08+00:00
sword
importub
filename=package.tar
b5cb3d28a987a9a95425087a7add0c93
Riedelsberger, Janin
Dreyer, Ingo
false
true
CC-BY - Namensnennung 4.0 International
Kamil Skłodowski
Janin Riedelsberger
Natalia Raddatz
Gonzalo Riadi
Julio Caballero
Isabelle Chérel
Waltraud Schulze
Alexander Graf
Ingo Dreyer
Biowissenschaften; Biologie
Institut für Biochemie und Biologie
Referiert
Import
34926
2013
2013
eng
16
4
review
Frontiers Research Foundation
Lausanne
1
--
--
--
The role of K+ channels in uptake and redistribution of potassium in the model plant Arabidopsis thaliana
Potassium (K+) is inevitable for plant growth and development. It plays a crucial role in the regulation of enzyme activities, in adjusting the electrical membrane potential and the cellular turgor, in regulating cellular homeostasis and in the stabilization of protein synthesis. Uptake of K+ from the soil and its transport to growing organs is essential for a healthy plant development. Uptake and allocation of K+ are performed by K+ channels and transporters belonging to different protein families. In this review we summarize the knowledge on the versatile physiological roles of plant K+ channels and their behavior under stress conditions in the model plant Arabidopsis thaliana.
Frontiers in plant science
10.3389/fpls.2013.00224
1664-462X
wos:2011-2013
224
WOS:000330169200001
Dreyer, I (reprint author), Univ Politecn Madrid, Ctr Biotecnol & Genom Plantas, Campus Montegancedo,Carretera M-40,Km 37-7, E-28223 Madrid, Spain., ingo.dreyer@upm.es; janin.riedelsberger@uni-potsdam.de
Spanish Ministerio de Economia y Competitividad [BFU2011-28815];
Marie-Curie Career Integration Grant [303674-Regopoc]; Deutsche
Forschungsgemeinschaft to Ingo Dreyer (DFG) [DR430/8-1, DR430/9-1];
International Max-Planck Research School
Tripti Sharma
Ingo Dreyer
Janin Riedelsberger
eng
uncontrolled
plant potassium channel
eng
uncontrolled
Shaker
eng
uncontrolled
TPK
eng
uncontrolled
K-ir-like
eng
uncontrolled
Arabidopsis thaliana
eng
uncontrolled
voltage-dependent
eng
uncontrolled
voltage-independent
Institut für Biochemie und Biologie
Referiert
Open Access
37499
2014
2014
eng
960
U776
19
2
166
article
American Society of Plant Physiologists
Rockville
1
--
--
--
Voltage-sensor transitions of the inward-rectifying K+ channel KAT1 indicate a latching mechanism biased by hydration within the voltage sensor
The Kv-like (potassium voltage-dependent) K+ channels at the plasma membrane, including the inward-rectifying KAT1 K+ channel of Arabidopsis (Arabidopsis thaliana), are important targets for manipulating K+ homeostasis in plants. Gating modification, especially, has been identified as a promising means by which to engineer plants with improved characteristics in mineral and water use. Understanding plant K+ channel gating poses several challenges, despite many similarities to that of mammalian Kv and Shaker channel models. We have used site-directed mutagenesis to explore residues that are thought to form two electrostatic countercharge centers on either side of a conserved phenylalanine (Phe) residue within the S2 and S3 alpha-helices of the voltage sensor domain (VSD) of Kv channels. Consistent with molecular dynamic simulations of KAT1, we show that the voltage dependence of the channel gate is highly sensitive to manipulations affecting these residues. Mutations of the central Phe residue favored the closed KAT1 channel, whereas mutations affecting the countercharge centers favored the open channel. Modeling of the macroscopic current kinetics also highlighted a substantial difference between the two sets of mutations. We interpret these findings in the context of the effects on hydration of amino acid residues within the VSD and with an inherent bias of the VSD, when hydrated around a central Phe residue, to the closed state of the channel.
Plant physiology : an international journal devoted to physiology, biochemistry, cellular and molecular biology, biophysics and environmental biology of plants
10.1104/pp.114.244319
25185120
0032-0889
1532-2548
wos:2014
WOS:000345071500043
Gonzalez, W (reprint author), Univ Talca, Ctr Bioinformat & Simulac Mol, Casilla 721, Talca, Chile., wgonzalez@utalca.cl; michael.blatt@glasgow.ac.uk
Biotechnology and Biological Sciences Research Council [BB/H001673/1,
BB/H024867/1, BB/H009817/1, BB/K015893/1]; ANILLO [ACT1104]; Deutsche
Forschungsgemeinschaft [DR430/8-1]
Cecile Lefoulon
Rucha Karnik
Annegret Honsbein
Paul Vijay Gutla
Christopher Grefen
Janin Riedelsberger
Tomas Poblete
Ingo Dreyer
Wendy Gonzalez
Michael R. Blatt
Institut für Biochemie und Biologie
Referiert