title: Activation of RidA chaperone function by N-chlorination.
abstract: Escherichia coli RidA is a member of a structurally conserved, yet functionally highly diverse protein family involved in translation inhibition (human), Hsp90-like chaperone activity (fruit fly) and enamine/imine deamination (Salmonella enterica). Here, we show that E. coli RidA modified with HOCl acts as a highly effective chaperone. Although activation of RidA is reversed by treatment with DTT, ascorbic acid, the thioredoxin system and glutathione, it is independent of cysteine modification. Instead, treatment with HOCl or chloramines decreases the amino group content of RidA by reversibly N-chlorinating positively charged residues. N-chlorination increases hydrophobicity of RidA and promotes binding to a wide spectrum of unfolded cytosolic proteins. Deletion of ridA results in an HOCl-sensitive phenotype. HOCl-mediated N-chlorination thus is a cysteine-independent post-translational modification that reversibly turns RidA into an effective chaperone holdase, which plays a crucial role in the protection of cytosolic proteins during oxidative stress.
authors.affiliation: Institute of Biochemistry and Pathobiochemistry-Microbial Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Alexandra
authors.initials: A
authors.lastname: Müller
authors.affiliation: Biology of Microorganisms, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Sina
authors.initials: S
authors.lastname: Langklotz
authors.affiliation: Institute of Biochemistry and Pathobiochemistry-Microbial Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Nataliya
authors.initials: N
authors.lastname: Lupilova
authors.affiliation: Medizinisches Proteom-Center, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Katja
authors.initials: K
authors.lastname: Kuhlmann
authors.affiliation: Biology of Microorganisms, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Julia Elisabeth
authors.initials: JE
authors.lastname: Bandow
authors.affiliation: Institute of Biochemistry and Pathobiochemistry-Microbial Biochemistry, Ruhr-Universität Bochum, Universitätsstrasse 150, 44780 Bochum, Germany.
authors.forename: Lars Ingo Ole
authors.initials: LI
authors.lastname: Leichert
mesh_terms: D000818:Animals; D001205:Ascorbic Acid / Q000737:chemistry; D001426:Bacterial Proteins / Q000819:agonists* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D004926:Escherichia coli / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D029968:Escherichia coli Proteins / Q000819:agonists* / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D017353:Gene Deletion; D005978:Glutathione / Q000737:chemistry; D054879:Halogenation; D006801:Humans; D006843:Hydrocarbons, Chlorinated / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D006997:Hypochlorous Acid / Q000737:chemistry* / Q000494:pharmacology; D018832:Molecular Chaperones / Q000819:agonists* / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding; D017510:Protein Folding; D011499:Protein Processing, Post-Translational; D055672:Static Electricity; D013879:Thioredoxins / Q000737:chemistry
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006843:Hydrocarbons, Chlorinated; D018832:Molecular Chaperones; C116617:YjgF protein, Bacteria; D013879:Thioredoxins; D006997:Hypochlorous Acid; D005978:Glutathione; D001205:Ascorbic Acid