The Clp protease system is required for copper ion-dependent turnover of the PAA2/HMA8 copper transporter in chloroplasts
© 2014 The Authors. New Phytologist © 2014 New Phytologist Trust.
| Veröffentlicht in: | The New phytologist. - 1979. - 205(2015), 2 vom: 07. Jan., Seite 511-7 |
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| 1. Verfasser: | |
| Weitere Verfasser: | , , , |
| Format: | Online-Aufsatz |
| Sprache: | English |
| Veröffentlicht: |
2015
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| Zugriff auf das übergeordnete Werk: | The New phytologist |
| Schlagworte: | Journal Article Research Support, U.S. Gov't, Non-P.H.S. P1B-type ATPase caseinolytic protease (Clp) chloroplast copper (Cu) homeostasis copper transport proteolysis regulated protein turnover Arabidopsis Proteins mehr... |
| Zusammenfassung: | © 2014 The Authors. New Phytologist © 2014 New Phytologist Trust. The distribution of essential metal ions over subcellular compartments for use as cofactors requires control of membrane transporters. PAA2/HMA8 is a copper-transporting P1B -type ATPase in the thylakoid membrane, required for the maturation of plastocyanin. When copper is highly available to the plant this transporter is degraded, which implies the action of a protease. In order to identify the proteolytic machinery responsible for PAA2/HMA8 turnover in Arabidopsis, mutant lines defective in five different chloroplast protease systems were analyzed. Plants defective in the chloroplast caseinolytic protease (Clp) system were specifically impaired in PAA2/HMA8 protein turnover on media containing elevated copper concentrations. However, the abundance of a core Clp component was not directly affected by copper. Furthermore, the expression and activity of both cytosolic and chloroplast-localized superoxide dismutases (SODs), which are known to be dependent on copper, were not altered in the clp mutants, indicating that the loss of PAA2/HMA8 turnover in these lines was not caused by a lack of stromal copper. The results suggest that copper excess in the stroma triggers selection of the thylakoid-localized PAA2 transporter for degradation by the Clp protease, but not several other chloroplast proteases, and support a novel role for this proteolytic system in cellular copper homeostasis |
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| Beschreibung: | Date Completed 31.08.2015 Date Revised 30.09.2020 published: Print-Electronic Citation Status MEDLINE |
| ISSN: | 1469-8137 |
| DOI: | 10.1111/nph.13093 |