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TPC1-Type Channels in Physcomitrium patens: Interaction between EF-Hands and Ca2+

Authors :
Franko Mérida-Quesada
Fernando Vergara-Valladares
María Eugenia Rubio-Meléndez
Naomí Hernández-Rojas
Angélica González-González
Erwan Michard
Carlos Navarro-Retamal
Ingo Dreyer
Source :
Plants, Vol 11, Iss 24, p 3527 (2022)
Publication Year :
2022
Publisher :
MDPI AG, 2022.

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.

Details

Language :
English
ISSN :
22237747
Volume :
11
Issue :
24
Database :
Directory of Open Access Journals
Journal :
Plants
Publication Type :
Academic Journal
Accession number :
edsdoj.5a7494c3733c4a87bd2025c86a54ddaf
Document Type :
article
Full Text :
https://doi.org/10.3390/plants11243527