Two chloroplast-localized MORF proteins act as chaperones to maintain tetrapyrrole biosynthesis
© 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation.
| Veröffentlicht in: | The New phytologist. - 1979. - 235(2022), 5 vom: 06. Sept., Seite 1868-1883 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2022
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, Non-U.S. Gov't GUN4 MORF POR chaperone tetrapyrrole biosynthesis Arabidopsis Proteins Chloroplast Proteins GUN4 protein, Arabidopsis mehr... |
| Zusammenfassung: | © 2022 The Authors. New Phytologist © 2022 New Phytologist Foundation. Tetrapyrroles have essential functions as pigments and cofactors during plant growth and development, and the tetrapyrrole biosynthesis pathway is tightly controlled. Multiple organellar RNA editing factors (MORFs) are required for editing of a wide variety of RNA sites in chloroplasts and mitochondria, but their biochemical properties remain elusive. Here, we uncovered the roles of chloroplast-localized MORF2 and MORF9 in modulating tetrapyrrole biosynthesis and embryogenesis in Arabidopsis thaliana. The lack or reduced transcripts of MORF2 or MORF9 significantly affected biosynthesis of the tetrapyrrole precursor 5-aminolevulinic acid and accumulation of Chl and other tetrapyrrole intermediates. MORF2 directly interacts with multiple tetrapyrrole biosynthesis enzymes and regulators, including NADPH:PROTOCHLOROPHYLLIDE OXIDOREDUCTASE B (PORB) and GENOMES UNCOUPLED4 (GUN4). Strikingly, MORF2 and MORF9 display holdase chaperone activity, alleviate the aggregation of PORB in vitro, and are essential for POR accumulation in vivo. Moreover, both MORF2 and MORF9 significantly stimulate magnesium chelatase activity. Our findings reveal a previously unknown biochemical property of MORF proteins as chaperones and point to a new layer of post-translational control of the tightly regulated tetrapyrrole biosynthesis in plants |
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| Beschreibung: | Date Completed 03.08.2022 Date Revised 24.08.2022 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.18273 |