title: Evidence of complex transcriptional, translational, and posttranslational regulation of the extracytoplasmic function sigma factor sigmaE in Mycobacterium tuberculosis.
abstract: The extracytoplasmic factor (ECF) sigma factor sigma(E) is one of the most studied sigma factors of Mycobacterium tuberculosis. It has been shown to be involved in virulence as well as in survival under conditions of high temperature, alkaline pH, and exposure to detergents and oxidative stress. Unlike many ECF sigma factors, sigma(E) does not directly regulate the transcription of its own gene. Two promoters have been identified upstream of the sigE gene; one is regulated by the two-component system MprAB, while the other has been shown to be sigma(H) dependent. In this paper, we further characterize the regulation of sigma(E) by identifying its anti-sigma factor and a previously unknown promoter. Finally, we show that sigE can be translated from three different translational start codons, depending on the promoter used. Taken together, our data demonstrate that sigma(E) not only is subjected to complex transcriptional regulation but is also controlled at the translational and posttranslational levels.
authors.affiliation: Department of Histology, Microbiology and Medical Biotechnologies, University of Padova, Via Gabelli, 63 35100 Padova, Italy.
authors.forename: Valentina
authors.initials: V
authors.lastname: Donà
authors.forename: Sébastien
authors.initials: S
authors.lastname: Rodrigue
authors.forename: Elisa
authors.initials: E
authors.lastname: Dainese
authors.forename: Giorgio
authors.initials: G
authors.lastname: Palù
authors.forename: Luc
authors.initials: L
authors.lastname: Gaudreau
authors.forename: Riccardo
authors.initials: R
authors.lastname: Manganelli
authors.forename: Roberta
authors.initials: R
authors.lastname: Provvedi
mesh_terms: D001426:Bacterial Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D001483:Base Sequence; D003958:Diamide / Q000494:pharmacology; D015964:Gene Expression Regulation, Bacterial; D008969:Molecular Sequence Data; D016297:Mutagenesis, Site-Directed; D009169:Mycobacterium tuberculosis / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D011401:Promoter Regions, Genetic / Q000235:genetics; D014176:Protein Biosynthesis / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012808:Sigma Factor / Q000235:genetics* / Q000378:metabolism / Q000502:physiology; D012967:Sodium Dodecyl Sulfate / Q000494:pharmacology; D024363:Transcription Initiation Site; D014158:Transcription, Genetic / Q000187:drug effects
chemical_list: D001426:Bacterial Proteins; D012333:RNA, Messenger; D012808:Sigma Factor; D003958:Diamide; D012967:Sodium Dodecyl Sulfate