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PPR Protein BFA2 Is Essential for the Accumulation of the atpH/F Transcript in Chloroplasts
Lin Zhang1, Wen Zhou2, Liping Che1
1Shanghai Key Laboratory of Plant Molecular Sciences, College of Life Sciences, Shanghai Normal University, Shanghai, China.
Frontiers in Plant Science
|April 30, 2019
Summary
A novel protein, Biogenesis Factor required for ATP synthase 2 (BFA2), is crucial for chloroplast ATP synthase accumulation in Arabidopsis. BFA2 stabilizes the atpH/F transcript, preventing its degradation and ensuring proper enzyme function.
Area of Science:
- Plant molecular biology
- Chloroplast biogenesis
- Protein-RNA interactions
Background:
- Chloroplast ATP synthase is a complex nanomotor essential for photosynthesis.
- Its biogenesis requires coordination between nuclear and plastid genomes.
- Nucleus-encoded factors regulate expression of plastid-encoded genes.
Purpose of the Study:
- To identify nucleus-encoded factors involved in chloroplast ATP synthase biogenesis.
- To characterize the function of a novel P-class pentatricopeptide repeat (PPR) protein, BFA2.
- To elucidate the mechanism by which BFA2 influences atpH/F transcript accumulation.
Main Methods:
- Genetic analysis of Arabidopsis mutants.
- Transcript accumulation analysis.
- Bioinformatics and Electrophoretic Mobility Shift Assays (EMSA).
Main Results:
- Loss-of-function mutation in BFA2 severely reduces chloroplast ATP synthase levels.
- BFA2 is essential for the accumulation of the dicistronic atpH/F transcript.
- BFA2 binds specifically to the atpF-atpA intergenic region.
- BFA2's function is independent of atpA translation initiation.
Conclusions:
- BFA2 is a chloroplast-localized PPR protein critical for stabilizing the atpH/F transcript.
- BFA2 acts as a protective barrier against exoribonucleases, preventing transcript degradation.
- This stabilization is essential for maintaining adequate levels of chloroplast ATP synthase.
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