title: Escherichia coli FtsH is a membrane-bound, ATP-dependent protease which degrades the heat-shock transcription factor sigma 32.
abstract: Escherichia coli FtsH is an essential integral membrane protein that has an AAA-type ATPase domain at its C-terminal cytoplasmic part, which is homologous to at least three ATPase subunits of the eukaryotic 26S proteasome. We report here that FtsH is involved in degradation of the heat-shock transcription factor sigma 32, a key element in the regulation of the E. coli heat-shock response. In the temperature-sensitive ftsH1 mutant, the amount of sigma 32 at a non-permissive temperature was higher than in the wild-type under certain conditions due to a reduced rate of degradation. In an in vitro system with purified components, FtsH catalyzed ATP-dependent degradation of biologically active histidine-tagged sigma 32. FtsH has a zinc-binding motif similar to the active site of zinc-metalloproteases. Protease activity of FtsH for histidine-tagged sigma 32 was stimulated by Zn2+ and strongly inhibited by the heavy metal chelating agent o-phenanthroline. We conclude that FtsH is a novel membrane-bound, ATP-dependent metalloprotease with activity for sigma 32. These findings indicate a new mechanism of gene regulation in E. coli.
authors.affiliation: Department of Molecular Cell Biology, Kumamoto University School of Medicine, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Tomoyasu
authors.forename: J
authors.initials: J
authors.lastname: Gamer
authors.forename: B
authors.initials: B
authors.lastname: Bukau
authors.forename: M
authors.initials: M
authors.lastname: Kanemori
authors.forename: H
authors.initials: H
authors.lastname: Mori
authors.forename: A J
authors.initials: AJ
authors.lastname: Rutman
authors.forename: A B
authors.initials: AB
authors.lastname: Oppenheim
authors.forename: T
authors.initials: T
authors.lastname: Yura
authors.forename: K
authors.initials: K
authors.lastname: Yamanaka
authors.forename: H
authors.initials: H
authors.lastname: Niki
mesh_terms: D049069:ATP-Dependent Proteases; D000251:Adenosine Triphosphatases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D001665:Binding Sites; D002413:Cations, Divalent / Q000494:pharmacology; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism*; D029968:Escherichia coli Proteins; D015964:Gene Expression Regulation, Bacterial; D005798:Genes, Bacterial; D006360:Heat-Shock Proteins / Q000378:metabolism*; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D009711:Nucleotides / Q000378:metabolism; D011480:Protease Inhibitors / Q000494:pharmacology; D012808:Sigma Factor / Q000378:metabolism*; D013379:Substrate Specificity; D013696:Temperature; D014157:Transcription Factors / Q000378:metabolism; D014764:Viral Proteins
chemical_list: D001426:Bacterial Proteins; D002413:Cations, Divalent; D029968:Escherichia coli Proteins; D006360:Heat-Shock Proteins; D008565:Membrane Proteins; D009711:Nucleotides; D011480:Protease Inhibitors; D012808:Sigma Factor; D014157:Transcription Factors; D014764:Viral Proteins; C039000:cII protein, bacteriophage lambda; C069774:heat-shock sigma factor 32; D049069:ATP-Dependent Proteases; C513383:FtsH protein, E coli; D000251:Adenosine Triphosphatases