Publicaciones de Erwan Michard
2025
Contador-Álvarez, Leslie; Rojas-Rocco, Tamara; Rodríguez-Gómez, Talía; Rubio-Meléndez, María Eugenia; Riedelsberger, Janin; Michard, Erwan; Dreyer, Ingo
Dynamics of homeostats: the basis of electrical, chemical, hydraulic, pH and calcium signaling in plants Artículo de revista
En: 2025.
@article{nokey,
title = {Dynamics of homeostats: the basis of electrical, chemical, hydraulic, pH and calcium signaling in plants},
author = {Leslie Contador-Álvarez and Tamara Rojas-Rocco and Talía Rodríguez-Gómez and María Eugenia Rubio-Meléndez and Janin Riedelsberger and Erwan Michard and Ingo Dreyer},
doi = {10.1017/qpb.2025.6},
year = {2025},
date = {2025-03-21},
urldate = {2025-03-21},
abstract = {Homeostats are important to control homeostatic conditions. Here, we have analyzed the theoretical basis of their dynamic properties by bringing the K homeostat out of steady state (i) by an electrical stimulus, (ii) by an external imbalance in the K+ or H+ gradient or (iii) by a readjustment of transporter activities. The reactions to such changes can be divided into (i) a short-term response (tens of milliseconds), where the membrane voltage changed along with the concentrations of ions that are not very abundant in the cytosol (H+ and Ca2+), and (ii) a long-term response (minutes and longer) caused by the slow changes in K+ concentrations. The mechanistic insights into its dynamics are not limited to the K homeostat but can be generalized, providing a new perspective on electrical, chemical, hydraulic, pH and Ca2+ signaling in plants. The results presented here also provide a theoretical background for optogenetic experiments in plants.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Homeostats are important to control homeostatic conditions. Here, we have analyzed the theoretical basis of their dynamic properties by bringing the K homeostat out of steady state (i) by an electrical stimulus, (ii) by an external imbalance in the K+ or H+ gradient or (iii) by a readjustment of transporter activities. The reactions to such changes can be divided into (i) a short-term response (tens of milliseconds), where the membrane voltage changed along with the concentrations of ions that are not very abundant in the cytosol (H+ and Ca2+), and (ii) a long-term response (minutes and longer) caused by the slow changes in K+ concentrations. The mechanistic insights into its dynamics are not limited to the K homeostat but can be generalized, providing a new perspective on electrical, chemical, hydraulic, pH and Ca2+ signaling in plants. The results presented here also provide a theoretical background for optogenetic experiments in plants.
2024
Dreyer, Ingo; Hernández-Rojas, Naomí; Bolua-Hernández, Yasnaya; Tapia-Castillo, Valentina De Los Angeles; Astola-Mariscal, Sadith Z.; Díaz-Pico, Erbio; Mérida-Quesada, Franko; Vergara-Valladares, Fernando; Arrey-Salas, Oscar; Rubio-Meléndez, María E.; Riedelsberger, Janin; Michard, Erwan
Homeostats: The hidden rulers of ion homeostasis in plants Artículo de revista
En: Quantitative Plant Biology, vol. 5, pp. e8, 2024, ISSN: 2632-8828.
@article{dreyer_homeostats_2024,
title = {Homeostats: The hidden rulers of ion homeostasis in plants},
author = {Ingo Dreyer and Naomí Hernández-Rojas and Yasnaya Bolua-Hernández and Valentina De Los Angeles Tapia-Castillo and Sadith Z. Astola-Mariscal and Erbio Díaz-Pico and Franko Mérida-Quesada and Fernando Vergara-Valladares and Oscar Arrey-Salas and María E. Rubio-Meléndez and Janin Riedelsberger and Erwan Michard},
url = {https://www.cambridge.org/core/product/identifier/S2632882824000080/type/journal_article},
doi = {10.1017/qpb.2024.8},
issn = {2632-8828},
year = {2024},
date = {2024-01-01},
urldate = {2024-12-14},
journal = {Quantitative Plant Biology},
volume = {5},
pages = {e8},
abstract = {Abstract
Ion homeostasis is a crucial process in plants that is closely linked to the efficiency of nutrient uptake, stress tolerance and overall plant growth and development. Nevertheless, our understanding of the fundamental processes of ion homeostasis is still incomplete and highly fragmented. Especially at the mechanistic level, we are still in the process of dissecting physiological systems to analyse the different parts in isolation. However, modelling approaches have shown that it is not individual transporters but rather transporter networks (homeostats) that control membrane transport and associated homeostatic processes in plant cells. To facilitate access to such theoretical approaches, the modelling of the potassium homeostat is explained here in detail to serve as a blueprint for other homeostats. The unbiased approach provided strong arguments for the abundant existence of electroneutral H
+
/K
+
antiporters in plants.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Abstract
Ion homeostasis is a crucial process in plants that is closely linked to the efficiency of nutrient uptake, stress tolerance and overall plant growth and development. Nevertheless, our understanding of the fundamental processes of ion homeostasis is still incomplete and highly fragmented. Especially at the mechanistic level, we are still in the process of dissecting physiological systems to analyse the different parts in isolation. However, modelling approaches have shown that it is not individual transporters but rather transporter networks (homeostats) that control membrane transport and associated homeostatic processes in plant cells. To facilitate access to such theoretical approaches, the modelling of the potassium homeostat is explained here in detail to serve as a blueprint for other homeostats. The unbiased approach provided strong arguments for the abundant existence of electroneutral H
+
/K
+
antiporters in plants.
Ion homeostasis is a crucial process in plants that is closely linked to the efficiency of nutrient uptake, stress tolerance and overall plant growth and development. Nevertheless, our understanding of the fundamental processes of ion homeostasis is still incomplete and highly fragmented. Especially at the mechanistic level, we are still in the process of dissecting physiological systems to analyse the different parts in isolation. However, modelling approaches have shown that it is not individual transporters but rather transporter networks (homeostats) that control membrane transport and associated homeostatic processes in plant cells. To facilitate access to such theoretical approaches, the modelling of the potassium homeostat is explained here in detail to serve as a blueprint for other homeostats. The unbiased approach provided strong arguments for the abundant existence of electroneutral H
+
/K
+
antiporters in plants.
2023
Dreyer, Ingo; Vergara-Valladares, Fernando; Mérida-Quesada, Franko; Rubio-Meléndez, María Eugenia; Hernández-Rojas, Naomí; Riedelsberger, Janin; Astola-Mariscal, Sadith Zobeida; Heitmüller, Charlotte; Yanez-Chávez, Mónica; Arrey-Salas, Oscar; Martín-Davison, Alex San; Navarro-Retamal, Carlos; Michard, Erwan
The Surprising Dynamics of Electrochemical Coupling at Membrane Sandwiches in Plants Artículo de revista
En: Plants, vol. 12, no 1, pp. 204, 2023, ISSN: 2223-7747.
@article{dreyer_surprising_2023,
title = {The Surprising Dynamics of Electrochemical Coupling at Membrane Sandwiches in Plants},
author = {Ingo Dreyer and Fernando Vergara-Valladares and Franko Mérida-Quesada and María Eugenia Rubio-Meléndez and Naomí Hernández-Rojas and Janin Riedelsberger and Sadith Zobeida Astola-Mariscal and Charlotte Heitmüller and Mónica Yanez-Chávez and Oscar Arrey-Salas and Alex San Martín-Davison and Carlos Navarro-Retamal and Erwan Michard},
url = {https://www.mdpi.com/2223-7747/12/1/204},
doi = {10.3390/plants12010204},
issn = {2223-7747},
year = {2023},
date = {2023-01-01},
urldate = {2024-12-14},
journal = {Plants},
volume = {12},
number = {1},
pages = {204},
abstract = {Transport processes across membranes play central roles in any biological system. They are essential for homeostasis, cell nutrition, and signaling. Fluxes across membranes are governed by fundamental thermodynamic rules and are influenced by electrical potentials and concentration gradients. Transmembrane transport processes have been largely studied on single membranes. However, several important cellular or subcellular structures consist of two closely spaced membranes that form a membrane sandwich. Such a dual membrane structure results in remarkable properties for the transport processes that are not present in isolated membranes. At the core of membrane sandwich properties, a small intermembrane volume is responsible for efficient coupling between the transport systems at the two otherwise independent membranes. Here, we present the physicochemical principles of transport coupling at two adjacent membranes and illustrate this concept with three examples. In the supplementary material, we provide animated PowerPoint presentations that visualize the relationships. They could be used for teaching purposes, as has already been completed successfully at the University of Talca.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Transport processes across membranes play central roles in any biological system. They are essential for homeostasis, cell nutrition, and signaling. Fluxes across membranes are governed by fundamental thermodynamic rules and are influenced by electrical potentials and concentration gradients. Transmembrane transport processes have been largely studied on single membranes. However, several important cellular or subcellular structures consist of two closely spaced membranes that form a membrane sandwich. Such a dual membrane structure results in remarkable properties for the transport processes that are not present in isolated membranes. At the core of membrane sandwich properties, a small intermembrane volume is responsible for efficient coupling between the transport systems at the two otherwise independent membranes. Here, we present the physicochemical principles of transport coupling at two adjacent membranes and illustrate this concept with three examples. In the supplementary material, we provide animated PowerPoint presentations that visualize the relationships. They could be used for teaching purposes, as has already been completed successfully at the University of Talca.
2022
Mérida-Quesada, Franko; Vergara-Valladares, Fernando; Rubio-Meléndez, María Eugenia; Hernández-Rojas, Naomí; González-González, Angélica; Michard, Erwan; Navarro-Retamal, Carlos; Dreyer, Ingo
TPC1-Type Channels in Physcomitrium patens: Interaction between EF-Hands and Ca2+ Artículo de revista
En: Plants, vol. 11, no 24, pp. 3527, 2022, ISSN: 2223-7747.
@article{merida-quesada_tpc1-type_2022,
title = {TPC1-Type Channels in Physcomitrium patens: Interaction between EF-Hands and Ca2+},
author = {Franko Mérida-Quesada and Fernando Vergara-Valladares and María Eugenia Rubio-Meléndez and Naomí Hernández-Rojas and Angélica González-González and Erwan Michard and Carlos Navarro-Retamal and Ingo Dreyer},
url = {https://www.mdpi.com/2223-7747/11/24/3527},
doi = {10.3390/plants11243527},
issn = {2223-7747},
year = {2022},
date = {2022-12-01},
urldate = {2024-12-14},
journal = {Plants},
volume = {11},
number = {24},
pages = {3527},
abstract = {Two-pore channels (TPCs) are members of the superfamily of ligand-gated and voltage-sensitive ion channels in the membranes of intracellular organelles of eukaryotic cells. The evolution of ordinary plant TPC1 essentially followed a very conservative pattern, with no changes in the characteristic structural footprints of these channels, such as the cytosolic and luminal regions involved in Ca2+ sensing. In contrast, the genomes of mosses and liverworts encode also TPC1-like channels with larger variations at these sites (TPC1b channels). In the genome of the model plant Physcomitrium patens we identified nine non-redundant sequences belonging to the TPC1 channel family, two ordinary TPC1-type, and seven TPC1b-type channels. The latter show variations in critical amino acids in their EF-hands essential for Ca2+ sensing. To investigate the impact of these differences between TPC1 and TPC1b channels, we generated structural models of the EF-hands of PpTPC1 and PpTPC1b channels. These models were used in molecular dynamics simulations to determine the frequency with which calcium ions were present in a coordination site and also to estimate the average distance of the ions from the center of this site. Our analyses indicate that the EF-hand domains of PpTPC1b-type channels have a lower capacity to coordinate calcium ions compared with those of common TPC1-like channels.},
keywords = {},
pubstate = {published},
tppubtype = {article}
}
Two-pore channels (TPCs) are members of the superfamily of ligand-gated and voltage-sensitive ion channels in the membranes of intracellular organelles of eukaryotic cells. The evolution of ordinary plant TPC1 essentially followed a very conservative pattern, with no changes in the characteristic structural footprints of these channels, such as the cytosolic and luminal regions involved in Ca2+ sensing. In contrast, the genomes of mosses and liverworts encode also TPC1-like channels with larger variations at these sites (TPC1b channels). In the genome of the model plant Physcomitrium patens we identified nine non-redundant sequences belonging to the TPC1 channel family, two ordinary TPC1-type, and seven TPC1b-type channels. The latter show variations in critical amino acids in their EF-hands essential for Ca2+ sensing. To investigate the impact of these differences between TPC1 and TPC1b channels, we generated structural models of the EF-hands of PpTPC1 and PpTPC1b channels. These models were used in molecular dynamics simulations to determine the frequency with which calcium ions were present in a coordination site and also to estimate the average distance of the ions from the center of this site. Our analyses indicate that the EF-hand domains of PpTPC1b-type channels have a lower capacity to coordinate calcium ions compared with those of common TPC1-like channels.
