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Your search keyword '"Janin Riedelsberger"' showing total 2 results
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2 results on '"Janin Riedelsberger"'

1. Transporter networks can serve plant cells as nutrient sensors and mimic transceptor-like behavior

Author

Ingo Dreyer, Kunkun Li, Janin Riedelsberger, Rainer Hedrich, Kai R. Konrad, and Erwan Michard

Subjects
Biological sciences, Mathematical biosciences, Plant biology, Plant physiology, Plant nutrition, Science
Abstract

Summary: Sensing of external mineral nutrient concentrations is essential for plants to colonize environments with a large spectrum of nutrient availability. Here, we analyzed transporter networks in computational cell biology simulations to understand better the initial steps of this sensing process. The networks analyzed were capable of translating the information of changing external nutrient concentrations into cytosolic H+ and Ca2+ signals, two of the most ubiquitous cellular second messengers. The concept emerging from the computational simulations was confirmed in wet-lab experiments. We document in guard cells that alterations in the external KCl concentration were translated into cytosolic H+ and Ca2+ transients as predicted. We show that transporter networks do not only serve their primary task of transport, but can also take on the role of a receptor without requiring conformational changes of a transporter protein. Such transceptor-like phenomena may be quite common in plants.

Published
2022
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2. Distributed structures underlie gating differences between the K in Channel KAT1 and the K out Channel SKOR

Author

Tripti Sharma, Pawel Gajdanowicz, Bernd Mueller-Roeber, Wendy González, Michael R. Blatt, Carlos García-Mata, Ingo Dreyer, Janin Riedelsberger, Samuel Elías Morales-Navarro, and Fernando D. González-Nilo

Subjects
Models, Molecular, K+ channel, Molecular Sequence Data, Arabidopsis, Gating, Plant Science, Biology, Molecular Dynamics Simulation, Protein Structure, Secondary, Ciencias Biológicas, Molecular dynamics, Shaker, Amino Acid Sequence, channel protein structure, Potassium Channels, Inwardly Rectifying, Molecular Biology, K channels, Sequence Homology, Amino Acid, Inward-rectifier potassium ion channel, Arabidopsis Proteins, K+-dependent, channel protein–cation interaction, Bioquímica y Biología Molecular, inward rectifier, Potassium channel, Electrophysiology, gating, Biophysics, Shaker Superfamily of Potassium Channels, outward rectifier, CIENCIAS NATURALES Y EXACTAS, Communication channel
Abstract

The family of voltage-gated (Shaker-like) potassium channels in plants includes both inward-rectifying (Kin) channels that allow plant cells to accumulate K+ and outward-rectifying (Kout) channels that mediate K+ efflux. Despite their close structural similarities, Kin and Kout channels differ in their gating sensitivity towards voltage and the extracellular K+ concentration. We have carried out a systematic program of domain swapping between the Kout channel SKOR and the Kin channel KAT1 to examine the impacts on gating of the pore regions, the S4, S5, and the S6 helices. We found that, in particular, the N-terminal part of the S5 played a critical role in KAT1 and SKOR gating. Our findings were supported by molecular dynamics of KAT1 and SKOR homology models. In silico analysis revealed that during channel opening and closing, displacement of certain residues, especially in the S5 and S6 segments, is more pronounced in KAT1 than in SKOR. From our analysis of the S4–S6 region, we conclude that gating (and K+-sensing in SKOR) depend on a number of structural elements that are dispersed over this ∼145-residue sequence and that these place additional constraints on configurational rearrangement of the channels during gating. Fil: Riedelsberger, Janin . Universität Potsdam; Alemania. Max-Planck Institute of Molecular Plant Physiology; Alemania Fil: Sharma, Tripti . Universität Potsdam; Alemania. Max-Planck Institute of Molecular Plant Physiology; Alemania Fil: Gonzalez, Wendy . Universidad de Talca; Chile Fil: Gajdanowicz, Pawel . Universität Potsdam; Alemania Fil: Morales Navarro, Samuel Elías . Universidad de Talca; Chile Fil: Garcia-Mata, Carlos. University Of Glasgow; Reino Unido. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Mueller Roeber, Bernd. Max-Planck Institute of Molecular Plant Physiology; Alemania. Universität Potsdam; Alemania Fil: González Nilo, Fernando Danilo . Universidad de Talca; Chile Fil: Blatt, Michael R. . University Of Glasgow; Reino Unido Fil: Dreyer, Ingo . Universität Potsdam; Alemania

Published
2010

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