Voltage-dependent gating of SV channel TPC1 confers vacuole excitability.
Dawid JaślanIngo DreyerJinping LuRonan O'MalleyJulian DindasIrene MartenRainer HedrichPublished in: Nature communications (2019)
In contrast to the plasma membrane, the vacuole membrane has not yet been associated with electrical excitation of plants. Here, we show that mesophyll vacuoles from Arabidopsis sense and control the membrane potential essentially via the K+-permeable TPC1 and TPK channels. Electrical stimuli elicit transient depolarization of the vacuole membrane that can last for seconds. Electrical excitability is suppressed by increased vacuolar Ca2+ levels. In comparison to wild type, vacuoles from the fou2 mutant, harboring TPC1 channels insensitive to luminal Ca2+, can be excited fully by even weak electrical stimuli. The TPC1-loss-of-function mutant tpc1-2 does not respond to electrical stimulation at all, and the loss of TPK1/TPK3-mediated K+ transport affects the duration of TPC1-dependent membrane depolarization. In combination with mathematical modeling, these results show that the vacuolar K+-conducting TPC1 and TPK1/TPK3 channels act in concert to provide for Ca2+- and voltage-induced electrical excitability to the central organelle of plant cells.
Keyphrases
- wild type
- transcranial direct current stimulation
- magnetic resonance
- spinal cord injury
- transcription factor
- protein kinase
- high glucose
- computed tomography
- magnetic resonance imaging
- cell death
- endothelial cells
- diabetic rats
- working memory
- brain injury
- contrast enhanced
- signaling pathway
- climate change
- cerebral ischemia
- endoplasmic reticulum stress
- clinical evaluation