TY  - JOUR
A1  - Lu, Jinping
A1  - Dreyer, Ingo
A1  - Dickinson, Miles Sasha
A1  - Panzer, Sabine
A1  - Jaślan, Dawid
A1  - Navarro-Retamal, Carlos
A1  - Geiger, Dietmar
A1  - Terpitz, Ulrich
A1  - Becker, Dirk
A1  - Stroud, Robert M.
A1  - Marten, Irene
A1  - Hedrich, Rainer
T1  - Vicia faba SV channel VfTPC1 is a hyperexcitable variant of plant vacuole two pore channels
JF  - eLife
N2  - To fire action-potential-like electrical signals, the vacuole membrane requires the two-pore channel TPC1, formerly called SV channel. The TPC1/SV channel functions as a depolarization-stimulated, non-selective cation channel that is inhibited by luminal Ca\(^{2+}\). In our search for species-dependent functional TPC1 channel variants with different luminal Ca\(^{2+}\) sensitivity, we found in total three acidic residues present in Ca\(^{2+}\) sensor sites 2 and 3 of the Ca\(^{2+}\)-sensitive AtTPC1 channel from Arabidopsis thaliana that were neutral in its Vicia faba ortholog and also in those of many other Fabaceae. When expressed in the Arabidopsis AtTPC1-loss-of-function background, wild-type VfTPC1 was hypersensitive to vacuole depolarization and only weakly sensitive to blocking luminal Ca\(^{2+}\). When AtTPC1 was mutated for these VfTPC1-homologous polymorphic residues, two neutral substitutions in Ca\(^{2+}\) sensor site 3 alone were already sufficient for the Arabidopsis At-VfTPC1 channel mutant to gain VfTPC1-like voltage and luminal Ca\(^{2+}\) sensitivity that together rendered vacuoles hyperexcitable. Thus, natural TPC1 channel variants exist in plant families which may fine-tune vacuole excitability and adapt it to environmental settings of the particular ecological niche.
KW  - A. thaliana
KW  - Brassicaceae
KW  - Fabaceae
KW  - pore
KW  - potassium channel
KW  - voltage gating
KW  - vacuolar calcium sensor
Y1  - 2023
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-350264
VL  - 12
ER  -