Functional analysis of Brassica napus phloem protein and ribonucleoprotein complexes
© 2017 The Authors. New Phytologist © 2017 New Phytologist Trust.
| Publié dans: | The New phytologist. - 1990. - 214(2017), 3 vom: 02. Mai, Seite 1188-1197 |
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| Auteur principal: | |
| Autres auteurs: | , , , , , , |
| Format: | Article en ligne |
| Langue: | English |
| Publié: |
2017
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| Accès à la collection: | The New phytologist |
| Sujets: | Journal Article Brassica napus blue native PAGE mass spectrometry phloem proteasome-mediated protein degradation protein complex ribonucleoprotein complex Multiprotein Complexes Plant Proteins plus... |
| Résumé: | © 2017 The Authors. New Phytologist © 2017 New Phytologist Trust. Phloem sap contains a large number of macromolecules, including proteins and RNAs from different classes. Proteome analyses of phloem samples from different plant species under denaturing conditions identified hundreds of proteins potentially involved in diverse processes. Surprisingly, these studies also found a significant number of ribosomal and proteasomal proteins. This led to the suggestion that active ribosome and proteasome complexes might be present in the phloem, challenging the paradigm that protein synthesis and turnover are absent from the enucleate sieve elements of angiosperms. However, the existence of such complexes has as yet not been demonstrated. In this study we used three-dimensional gel electrophoresis to separate several protein complexes from native phloem sap from Brassica napus. Matrix-assisted laser desorption ionization-time of flight MS analyses identified more than 100 proteins in the three major protein-containing complexes. All three complexes contained proteins belonging to different ribosomal fragments and blue native northern blot confirmed the existence of ribonucleoprotein complexes. In addition, one complex contained proteasome components and further functional analyses confirmed activity of a proteasomal degradation pathway and showed a large number of ubiquitinated phloem proteins. Our results suggest specialized roles for ubiquitin modification and proteasome-mediated degradation in the phloem |
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| Description: | Date Completed 16.02.2018 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.14405 |