Vicia faba SV channel VfTPC1 is a hyperexcitable variant of plant vacuole Two Pore Channels

• DOI: 10.7554/elife.86384
• Publication Date: 2023-11-22T16:10:08Z
• Authors: Jinping Lu; Ingo Dreyer; Miles Sasha Dicki...; Sabine Panzer; Dawid Jaślan; Carlos Navarro-Re...; Dietmar Geiger; Ulrich Terpitz; Dirk Becker; Robert M Stroud; Irene Marten; Rainer Hedrich
• Keywords: plant biology; QH301-705.5; Science; Q; R; Arabidopsis; Plant Biology; Action Potentials; Fabaceae; voltage gating; vacuolar calcium sensor; Vicia faba; A. thaliana; Brassicaceae; Vacuoles; molecular biophysics; structural biology; Medicine; ddc:580; Biology (General); pore; Ecosystem; potassium channel

To fire action-potential-like electrical signals, the vacuole membrane requires two-pore channel TPC1, formerly called SV channel. The TPC1/SV functions as a depolarization-stimulated, non-selective cation that is inhibited by luminal Ca 2+ . In our search for species-dependent functional TPC1 variants with different sensitivity, we found in total three acidic residues present sensor sites 2 and 3 of -sensitive AtTPC1 from Arabidopsis thaliana were neutral its Vicia faba ortholog also those many other Fabaceae. When expressed AtTPC1-loss-of-function background, wild-type VfTPC1 was hypersensitive to depolarization only weakly sensitive blocking mutated these VfTPC1-homologous polymorphic residues, two substitutions site alone already sufficient At-VfTPC1 mutant gain VfTPC1-like voltage sensitivity together rendered vacuoles hyperexcitable. Thus, natural exist plant families which may fine-tune excitability adapt it environmental settings particular ecological niche.