The K + exchange antiporter 3 senses the chloroplast energy status to synchronize photosynthesis
Preprint
Abstract
Plant photosynthesis contains two functional modules, the light-driven reactions in the thylakoid membrane and the carbon-fixing reactions in the chloroplast stroma. In nature, light availability for photosynthesis often undergoes massive and rapid fluctuations. Efficient and productive use of such variable light supply requires an instant crosstalk and rapid synchronization of both functional modules. Here, we show that this communication involves the stromal exposed regulatory C-terminus (RCT) of the thylakoid K + -exchange antiporter KEA3. RCT-mediated control of KEA3 contributes to the balance between light capture and photoprotection. By combining in silico, in vitro , and in vivo approaches, we demonstrate that the RCT senses the energy state of the chloroplast in form of both, phosphorylation and redox potential, in a pH-dependent manner and regulates KEA3 activity in response. Together our data pinpoint a regulatory feedback loop by which the stromal energy state orchestrates light capture and photoprotection via KEA3.Keywords
This publication has 44 references indexed in Scilit:
- Optimization of the Additive CHARMM All-Atom Protein Force Field Targeting Improved Sampling of the Backbone ϕ, ψ and Side-Chain χ1 and χ2 Dihedral AnglesJournal of Chemical Theory and Computation, 2012
- H++ 3.0: automating pK prediction and the preparation of biomolecular structures for atomistic molecular modeling and simulationsNucleic Acids Research, 2012
- SwissDock, a protein-small molecule docking web service based on EADock DSSNucleic Acids Research, 2011
- Fast docking using the CHARMM force field with EADock DSSJournal of Computational Chemistry, 2011
- Chlorophyll Fluorescence: A Probe of Photosynthesis In VivoAnnual Review of Plant Biology, 2008
- MolProbity: all-atom contacts and structure validation for proteins and nucleic acidsNucleic Acids Research, 2007
- A Second Thylakoid Membrane-localized Alb3/OxaI/YidC Homologue Is Involved in Proper Chloroplast Biogenesis in Arabidopsis thalianaJournal of Biological Chemistry, 2006
- Rapid Regulation of Light Harvesting and Plant Fitness in the FieldScience, 2002
- Comparative Protein Modelling by Satisfaction of Spatial RestraintsJournal of Molecular Biology, 1993
- Dictionary of protein secondary structure: Pattern recognition of hydrogen‐bonded and geometrical featuresBiopolymers, 1983