Primary restriction of S-RNase cytotoxicity by a stepwise ubiquitination and degradation pathway in Petunia hybrida
© 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation.
| Publié dans: | The New phytologist. - 1984. - 231(2021), 3 vom: 26. Aug., Seite 1249-1264 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2021
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Research Support, Non-U.S. Gov't Petunia hybrida S-RNase SLF self-incompatibility ubiquitination Plant Proteins Ribonucleases EC 3.1.- |
| Résumé: | © 2021 The Authors. New Phytologist © 2021 New Phytologist Foundation. In self-incompatible Petunia species, the pistil S-RNase acts as cytotoxin to inhibit self-pollination but is polyubiquitinated by the pollen-specific nonself S-locus F-box (SLF) proteins and subsequently degraded by the ubiquitin-proteasome system (UPS), allowing cross-pollination. However, it remains unclear how S-RNase is restricted by the UPS. Using biochemical analyses, we first show that Petunia hybrida S3 -RNase is largely ubiquitinated by K48-linked polyubiquitin chains at three regions, R I, R II and R III. R I is ubiquitinated in unpollinated, self-pollinated and cross-pollinated pistils, indicating its occurrence before PhS3 -RNase uptake into pollen tubes, whereas R II and R III are exclusively ubiquitinated in cross-pollinated pistils. Transgenic analyses showed that removal of R II ubiquitination resulted in significantly reduced seed sets from cross-pollination and that of R I and R III to a lesser extent, indicating their increased cytotoxicity. Consistent with this, the mutated R II of PhS3 -RNase resulted in a marked reduction of its degradation, whereas that of R I and R III resulted in less reduction. Taken together, we demonstrate that PhS3 -RNase R II functions as a major ubiquitination region for its destruction and R I and R III as minor ones, revealing that its cytotoxicity is primarily restricted by a stepwise UPS mechanism for cross-pollination in P. hybrida |
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| Description: | Date Completed 12.07.2021 Date Revised 18.08.2021 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.17438 |