Photoreceptor- induced LHL4 protects the photosystem II monomer in Chlamydomonas reinhardtii

• 成果类型: Article
• 署名作者: Dannay, Marie; Bertin, Chloe; Cavallari, Eva; Albanese, Pascal; Tolleter, Dimitri; Giustini, Cecile; Menneteau, Mathilde; Brugiere, Sabine; Coute, Yohann; Finazzi, Giovanni; Demarsy, Emilie; Ulm, Roman; Allorent, Guillaume
• 署名单位: Communaute Universite Grenoble Alpes; Centre National de la Recherche Scientifique (CNRS); CEA; INRAE; Universite Grenoble Alpes (UGA); University of Geneva; Institut National de la Sante et de la Recherche Medicale (Inserm); Communaute Universite Grenoble Alpes; Centre National de la Recherche Scientifique (CNRS); CEA; Universite Grenoble Alpes (UGA); University of Geneva; Universite Paris Saclay; Centre National de la Recherche Scientifique (CNRS); UNICANCER; Gustave Roussy
• 刊物名称: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• ISSN/ISSBN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.2418687122
• 发表日期: 2025-02-18
• 页码: e2418687122
• 关键词: ultraviolet-B; high light; photosynthesis; acclimation; UV-B RESPONSE; light-inducible proteins; chlorophyll fluorescence; expression; photoprotection; perception; EVOLUTION; reveals; stress; genes

摘要

Photosynthesis, the fundamental process using light energy to convert carbon dioxide to organic matter, is vital for life on Earth. It relies on capturing light through light- harvesting complexes (LHC) in photosystem I (PSI) and PSII and on the conver-sion of light energy into chemical energy. Composition and organization of PSI and PSII core complexes are well conserved across evolution. PSII is particularly sensitive to pho-todamage but benefits from a large diversity of photoprotective mechanisms, finely tuned to handle the dynamic and ever- changing light conditions. Light Harvesting Complex protein family members (LHC and LHC- like families) have acquired a dual function during evolution. Members of the LHC antenna complexes of PS capture light energy, whereas others dissipate excess energy that cannot be harnessed for photosynthesis. This process mainly occurs through nonphotochemical quenching (NPQ). In this work, we focus on the Light Harvesting complex- Like 4 (LHL4) protein, a LHC- like pro-tein induced by ultraviolet- B (UV- B) and blue light through UV Resistance locus 8 (UVR8) and phototropin photoreceptor- activated signaling pathways in the model green microalgae Chlamydomonas reinhardtii. We demonstrate that alongside established NPQ effectors, LHL4 plays a key role in photoprotection, preventing singlet oxygen accumu-lation in PSII and promoting cell survival upon light stress. LHL4 protective function is distinct from that of NPQ- related proteins, as LHL4 specifically and uniquely binds to the transient monomeric form of the core PSII complex, safeguarding its integrity. LHL4 characterization expands our understanding of the interplay between light har-vesting and photoprotection mechanisms upon light stress in photosynthetic microalgae.