CO-EXPRESSED WITH PSI ASSEMBLY1 (CEPA1) is a photosystem I assembly factor in Arabidopsis.
Plant Cell
; 2024 Feb 21.
Article
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| MEDLINE
| ID: mdl-38382089
ABSTRACT
Photosystem I (PSI) forms a large macromolecular complex of â¼580 kDa that resides in the thylakoid membrane and mediates photosynthetic electron transfer. PSI is composed of eighteen protein subunits and nearly two hundred co-factors. The assembly of the complex in thylakoid membranes requires high spatial and temporal coordination, and is critically dependent on a sophisticated assembly machinery. Here, we report and characterize CO-EXPRESSED WITH PSI ASSEMBLY1 (CEPA1), a PSI assembly factor in Arabidopsis (Arabidopsis thaliana). The CEPA1 gene was identified bioinformatically as being co-expressed with known PSI assembly factors. Disruption of the CEPA1 gene leads to a pale phenotype and retarded plant development but does not entirely abolish photoautotrophy. Biophysical and biochemical analyses revealed that the phenotype is caused by a specific defect in PSI accumulation. We further show that CEPA1 acts at the post-translational level and co-localizes with PSI in non-appressed thylakoid membranes. In native gels, CEPA1 co-migrates with thylakoid protein complexes, including putative PSI assembly intermediates. Finally, protein-protein interaction assays suggest cooperation of CEPA1 with the PSI assembly factor PHOTOSYSTEM I ASSEMBLY3 PSA3. Together, our data support an important but non-essential role of CEPA1 in PSI assembly.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Idioma:
En
Revista:
Plant Cell
Asunto de la revista:
BOTANICA
Año:
2024
Tipo del documento:
Article
País de afiliación:
Alemania
Pais de publicación:
Reino Unido