Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-10854
Krügel, U; Veenhoff, L M; Langbein, J; Wiederhold, E; Liesche, J; Friedrich, T; Grimm, B; Martinoia, E; Poolman, B; Kühn, C (2008). Transport and sorting of the solanum tuberosum sucrose transporter SUT1 is affected by posttranslational modification. Plant Cell, 20(9):2497-2513.
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The plant sucrose transporter SUT1 from Solanum tuberosum revealed a dramatic redox-dependent increase in sucrose transport activity when heterologously expressed in Saccharomyces cerevisiae. Plant plasma membrane vesicles do not show any change in proton flux across the plasma membrane in the presence of redox reagents, indicating a SUT1-specific effect of redox reagents. Redox-dependent sucrose transport activity was confirmed electrophysiologically in Xenopus laevis oocytes with SUT1 from maize (Zea mays). Localization studies of green fluorescent protein fusion constructs showed that an oxidative environment increased the targeting of SUT1 to the plasma membrane where the protein concentrates in 200- to 300-nm raft-like microdomains. Using plant plasma membranes, St SUT1 can be detected in the detergent-resistant membrane fraction. Importantly, in yeast and in plants, oxidative reagents induced a shift in the monomer to dimer equilibrium of the St SUT1 protein and increased the fraction of dimer. Biochemical methods confirmed the capacity of SUT1 to form a dimer in plants and yeast cells in a redox-dependent manner. Blue native PAGE, chemical cross-linking, and immunoprecipitation, as well as the analysis of transgenic plants with reduced expression of St SUT1, confirmed the dimerization of St SUT1 and Sl SUT1 (from Solanum lycopersicum) in planta. The ability to form homodimers in plant cells was analyzed by the split yellow fluorescent protein technique in transiently transformed tobacco (Nicotiana tabacum) leaves and protoplasts. Oligomerization seems to be cell type specific since under native-like conditions, a phloem-specific reduction of the dimeric form of the St SUT1 protein was detectable in SUT1 antisense plants, whereas constitutively inhibited antisense plants showed reduction only of the monomeric form. The role of redox control of sucrose transport in plants is discussed.
|Item Type:||Journal Article, refereed, original work|
|Communities & Collections:||07 Faculty of Science > Institute of Plant Biology|
|DDC:||580 Plants (Botany)|
|Deposited On:||21 Feb 2009 20:42|
|Last Modified:||23 Nov 2012 17:38|
|Publisher:||American Society of Plant Biologists|
|Additional Information:||This is a pre-copy-editing. The definitive publisher-authenticated version "Transport and Sorting of the Solanum tuberosum Sucrose Transporter SUT1 Is Affected... Krügel et al. Plant Cell.2008; 20: 2497-2513" is available online at: http://www.plantcell.org/cgi/content/full/20/9/2497.|
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