title: Comprehensively Characterizing the Thioredoxin Interactome In Vivo Highlights the Central Role Played by This Ubiquitous Oxidoreductase in Redox Control.
abstract: Thioredoxin (Trx) is a ubiquitous oxidoreductase maintaining protein-bound cysteine residues in the reduced thiol state. Here, we combined a well-established method to trap Trx substrates with the power of bacterial genetics to comprehensively characterize the in vivo Trx redox interactome in the model bacterium Escherichia coli Using strains engineered to optimize trapping, we report the identification of a total 268 Trx substrates, including 201 that had never been reported to depend on Trx for reduction. The newly identified Trx substrates are involved in a variety of cellular processes, ranging from energy metabolism to amino acid synthesis and transcription. The interaction between Trx and two of its newly identified substrates, a protein required for the import of most carbohydrates, PtsI, and the bacterial actin homolog MreB was studied in detail. We provide direct evidence that PtsI and MreB contain cysteine residues that are susceptible to oxidation and that participate in the formation of an intermolecular disulfide with Trx. By considerably expanding the number of Trx targets, our work highlights the role played by this major oxidoreductase in a variety of cellular processes. Moreover, as the dependence on Trx for reduction is often conserved across species, it also provides insightful information on the interactome of Trx in organisms other than E. coli.
authors.affiliation: From the ‡WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium, §de Duve Institute, Université catholique de Louvain (UCL), Avenue Hippocrate 75, 1200 Brussels, Belgium; ¶Brussels Center for Redox Biology, Avenue Hippocrate 75, 1200 Brussels, Belgium.
authors.forename: Isabelle S
authors.initials: IS
authors.lastname: Arts
authors.affiliation: §de Duve Institute, Université catholique de Louvain (UCL), Avenue Hippocrate 75, 1200 Brussels, Belgium;
authors.forename: Didier
authors.initials: D
authors.lastname: Vertommen
authors.affiliation: From the ‡WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium, §de Duve Institute, Université catholique de Louvain (UCL), Avenue Hippocrate 75, 1200 Brussels, Belgium;
authors.forename: Francesca
authors.initials: F
authors.lastname: Baldin
authors.affiliation: From the ‡WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium, §de Duve Institute, Université catholique de Louvain (UCL), Avenue Hippocrate 75, 1200 Brussels, Belgium; ¶Brussels Center for Redox Biology, Avenue Hippocrate 75, 1200 Brussels, Belgium.
authors.forename: Géraldine
authors.initials: G
authors.lastname: Laloux
authors.affiliation: From the ‡WELBIO, Avenue Hippocrate 75, 1200 Brussels, Belgium, §de Duve Institute, Université catholique de Louvain (UCL), Avenue Hippocrate 75, 1200 Brussels, Belgium; ¶Brussels Center for Redox Biology, Avenue Hippocrate 75, 1200 Brussels, Belgium jfcollet@uclouvain.be.
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Collet
mesh_terms: D003545:Cysteine / Q000737:chemistry; D004926:Escherichia coli / Q000378:metabolism*; D029968:Escherichia coli Proteins / Q000737:chemistry / Q000378:metabolism*; D009004:Monosaccharide Transport Proteins / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System / Q000737:chemistry / Q000378:metabolism*; D011485:Protein Binding; D060066:Protein Interaction Maps; D040901:Proteomics / Q000379:methods; D013879:Thioredoxins / Q000378:metabolism*
chemical_list: D029968:Escherichia coli Proteins; D009004:Monosaccharide Transport Proteins; C078473:MreB protein, E coli; D013879:Thioredoxins; D010731:Phosphoenolpyruvate Sugar Phosphotransferase System; C022358:mannitol PTS permease, E coli; D003545:Cysteine