LTD coordinates chlorophyll biosynthesis and LIGHT-HARVESTING CHLOROPHYLL A/B-BINDING PROTEIN transport
Chlorophyll biosynthesis must be tightly coupled to light-harvesting chlorophyll a/b-binding protein (LHCP) biogenesis, as free chlorophyll and its precursors are phototoxic. However, precisely how these 2 processes are coordinated in Arabidopsis (Arabidopsis thaliana) remains elusive. Our previous studies demonstrated the role of LHCP TRANSLOCATION DEFECT (LTD) in delivering LHCPs to the chloroplast via the signal recognition particle-dependent pathway. Here, we show that LTD interacts with and stabilizes the chlorophyll biosynthesis enzymes Mg-protoporphyrin methyltransferase and Mg-protoporphyrin monomethylester (MgPME) cyclase, maintaining their activity. We also demonstrate the direct binding of LTD to MgPME, and through crystal structure analysis, we show that the groove of the LTD dimer is critical for MgPME binding. Thus, we propose that LTD transfers MgPME from Mg-protoporphyrin methyltransferase to the MgPME cyclase. These results elucidate a role for LTD in synchronizing chlorophyll biosynthesis with LHCP transport to ensure the correct insertion of chlorophylls into LHCPs.
Authors
- Y. H. Zheng (ORCID: https://orcid.org/0009-0007-8065-212X)
- X. T. Chen (ORCID: https://orcid.org/0009-0006-0700-4575)
- Junhang An (ORCID: https://orcid.org/0000-0001-5077-3691)
- Liwei Rong
- Zhubing Hu (ORCID: https://orcid.org/0000-0002-5394-9864)
- Min Ouyang (ORCID: https://orcid.org/0000-0002-2249-3470)
- Bernhard Grimm (ORCID: https://orcid.org/0000-0002-9730-1074)
- Xiumei Xu (ORCID: https://orcid.org/0000-0003-3515-1864)
- Guangyu E. Chen (ORCID: https://orcid.org/0000-0001-8457-819X)
- Chao Wang (ORCID: https://orcid.org/0000-0002-0534-8984)
- Peng Wang (ORCID: https://orcid.org/0000-0001-8420-5326)
- Wei Li (ORCID: https://orcid.org/0009-0009-1644-5059)
- Lixin Zhang
- Xin Chai (ORCID: https://orcid.org/0000-0002-0763-9574)
- Dandan Lu (ORCID: https://orcid.org/0000-0003-1034-220X)
- Jianghao Wu (ORCID: https://orcid.org/0009-0009-6869-3206)
- Xin Wang (ORCID: https://orcid.org/0009-0004-2370-0779)
Institutions
- Henan University (CN)
- Chinese University of Hong Kong (HK)
- Shanghai Jiao Tong University (CN)
- Chinese Academy of Sciences (CN)
- Chinese Academy of Medical Sciences & Peking Union Medical College (CN)
- Huazhong Agricultural University (CN)
- Humboldt-Universität zu Berlin (DE)
- Sanya University (CN)
- University of Hong Kong (HK)
Publication Details
- Journal
- The Plant Cell
- Published
- 2025-03-26
- DOI
- https://doi.org/10.1093/plcell/koaf068
- Citations
- 9
- Primary Topic
- Photosynthetic Processes and Mechanisms
- Type
- article
- Field-Weighted Citation Impact
- 7.25
Funders
- Deutsche Forschungsgemeinschaft
- National Natural Science Foundation of China
- Natural Science Foundation of Henan Province
- Higher Education Discipline Innovation Project
- National Key Research and Development Program of China
- Science and Technology Innovation Talents in Universities of Henan Province