Vacuolar sequestration of glutathione S-conjugates outcompetes a possible degradation of the glutathione moiety by phytochelatin synthase
Monochlorobimane was used as a model xenobiotic for Arabidopsis to directly monitor the compartmentation of glutathione-bimane conjugates in situ and to quantify degradation intermediates in vitro. Vacuolar sequestration of the conjugate was very fast and outcompeted carboxypeptidation to the γ-glut...
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| Main Authors: | , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
3 November 2006
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| In: |
FEBS letters
Year: 2006, Volume: 580, Issue: 27, Pages: 6384-6390 |
| ISSN: | 1873-3468 |
| DOI: | 10.1016/j.febslet.2006.10.050 |
| Online Access: | Verlag, kostenfrei, Volltext: http://dx.doi.org/10.1016/j.febslet.2006.10.050 Verlag, kostenfrei, Volltext: http://onlinelibrary.wiley.com/doi/10.1016/j.febslet.2006.10.050/epdf 
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| Author Notes: | Anke Grzam, Pierre Tennstedt, Stephan Clemens, Rudiger Hell, Andreas J. Meyer |
| Summary: | Monochlorobimane was used as a model xenobiotic for Arabidopsis to directly monitor the compartmentation of glutathione-bimane conjugates in situ and to quantify degradation intermediates in vitro. Vacuolar sequestration of the conjugate was very fast and outcompeted carboxypeptidation to the γ-glutamylcysteine-bimane intermediate (γ-EC-B) by phytochelatin synthase (PCS) in the cytosol. Following vacuolar sequestration, degradation proceeded to cysteine-bimane without intermediate. Only co-infiltration of monochlorobimane with Cd2+ and Cu2+ increased γ-EC-B formation to 4% and 25%, respectively, within 60 min. The role of PCS under simultaneous heavy metal stress was confirmed by investigation of different pcs1 null-mutants. In the absence of elevated heavy metal concentrations glutathione-conjugates are therefore first sequestered to the vacuole and subsequently degraded with the initial breakdown step being rate-limiting. |
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| Item Description: | Gesehen am 15.05.2017 |
| Physical Description: | Online Resource |
| ISSN: | 1873-3468 |
| DOI: | 10.1016/j.febslet.2006.10.050 |