Mechanically-primed voltage-gated proton channels from angiosperm plants

Area of Science:

• Plant molecular biology
• Ion channel biophysics
• Membrane protein function

Background:

• Voltage-gated and mechanically-gated ion channels are crucial for cellular function.
• Plant Hv channels (voltage-dependent H+ channels) are involved in various physiological processes.

Purpose of the Study:

• To characterize a novel gating mechanism in angiosperm Hv channels.
• To investigate the role of mechanical stimuli in Hv channel activation.
• To identify key residues involved in this unique gating modality.

Main Methods:

• Electrophysiological recordings
• AI-driven structural modeling of plant Hv homologs
• Site-directed mutagenesis to identify critical residues

Main Results:

• Angiosperm Hv channels exhibit a unique priming mechanism requiring prior mechanical stimulation for electrical gating.
• Mechanical priming is not necessary for non-angiosperm Hv channels.
• Specific hydrophilic/charged residues were identified as crucial for mechanical priming in angiosperms.
• AI-generated models guided the identification of these key residues.

Conclusions:

• Angiosperm Hv channels are electrically silent until mechanically primed.
• A network of charged residues maintains a resting conformation, which is destabilized by mechanical stimuli.
• This priming mechanism represents a novel gating modality for voltage-dependent ion channels in plants.