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Updated: Aug 15, 2026
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Published on: November 1, 2024
Decoding plant vacuolar phosphate efflux: Structural and dynamic insights from rice VPE2
Jiaqi Zuo1, Shuo Cao1, Ying Tang1
1National Key Laboratory of Crop Genetic Improvement, Hubei Provincial Research Center for Basic Biological Sciences, College of Bio-X, Hubei Hongshan Laboratory, Department of Biochemistry and Molecular Biology, Huazhong Agricultural University, Wuhan 430070, China.
Summary
Plant vacuoles store phosphorus, but how it exits remains unknown. Researchers discovered a pH-sensitive switch in the OsVPE2 transporter, crucial for releasing inorganic phosphate (Pi) and optimizing plant phosphorus use.
Area of Science:
- Plant Biology
- Molecular Biology
- Structural Biology
Background:
- Vacuoles are critical for plant phosphorus storage, buffering against nutrient stress.
- Mechanisms of vacuolar inorganic phosphate (Pi) release via VPEs are poorly understood.
Purpose of the Study:
- Elucidate the molecular mechanism of Pi transport by the rice vacuolar Pi efflux transporter, OsVPE2.
- Investigate the role of the vacuolar coupling helix (VCH) in OsVPE2 function.
Main Methods:
- Integrative structural biology (Cryo-EM)
- Single-molecule fluorescence resonance energy transfer (smFRET)
- Functional transport assays
Main Results:
- Cryo-EM structures revealed Pi-binding pocket and a pH-sensitive VCH motif.
- smFRET demonstrated VCH dynamics coupled to transporter conformational changes.
- VCH flexibility, not just presence, is essential for OsVPE2 transport activity.
Conclusions:
- The VCH acts as a pH-dependent conformational switch regulating OsVPE2 transport.
- This study provides the molecular blueprint for vacuolar Pi efflux.
- The VCH is a conserved regulatory element and a potential target for enhancing plant phosphorus use efficiency.
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