Identification of 1 distinct pH- and zeaxanthin-dependent quenching in LHCSR3 from chlamydomonas reinhardtii
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elife-60383-v2.pdf
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Published version
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711.56 KB
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Author(s)
Troiano, Julianne M.
Moya, Raymundo
Schlau-Cohen, Gabriela S
Date Issued
January 2021
Journal
eLife
Publisher
eLife Sciences Publications, Ltd
Citation
Troiano, Julianne M. et al. “Identification of 1 distinct pH- and zeaxanthin-dependent quenching in LHCSR3 from chlamydomonas reinhardtii.” eLife, 10 (January 2021): e60383 © 2021 The Author(s)
Version
Final published version
Abstract
Under high light, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating absorbed energy, which is called non-photochemical quenching. In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress17 related (LHCSR3), detects excess energy via a pH drop and serves as a quenching site. Using a combined in vivo and in vitro approach, we investigated quenching within LHCSR3 from Chlamydomonas reinhardtii. In vitro two distinct quenching processes, individually controlled by pH and zeaxanthin, were identified within LHCSR3. The pH21 dependent quenching was removed within a mutant LHCSR3 that lacks the residues that are protonated to sense the pH drop. Observation of quenching in zeaxanthin-enriched LHCSR3 even at neutral pH demonstrated zeaxanthin-dependent quenching, which also occurs in other light-harvesting complexes. Either pH- or zeaxanthin-dependent quenching prevented the formation of damaging reactive oxygen species, and thus the two quenching processes may together provide different induction and recovery kinetics for photoprotection in a changing environment.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Creative Commons Attribution 4.0 International license
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DOI of Published Version
https://doi.org/10.7554/eLife.60383
