title: A two-component regulatory system controls autoregulated serpin expression in Bifidobacterium breve UCC2003.
abstract: This work reports on the identification and molecular characterization of a two-component regulatory system (2CRS), encoded by serRK, which is believed to control the expression of the ser(2003) locus in Bifidobacterium breve UCC2003. The ser(2003) locus consists of two genes, Bbr_1319 (sagA) and Bbr_1320 (serU), which are predicted to encode a hypothetical membrane-associated protein and a serpin-like protein, respectively. The response regulator SerR was shown to bind to the promoter region of ser(2003), and the probable recognition sequence of SerR was determined by a combinatorial approach of in vitro site-directed mutagenesis coupled to transcriptional fusion and electrophoretic mobility shift assays (EMSAs). The importance of the serRK 2CRS in the response of B. breve to protease-mediated induction was confirmed by generating a B. breve serR insertion mutant, which was shown to exhibit altered ser(2003) transcriptional induction patterns compared to the parent strain, UCC2003. Interestingly, the analysis of a B. breve serU mutant revealed that the SerRK signaling pathway appears to include a SerU-dependent autoregulatory loop.
authors: Alimentary Pharmabiotic Centre and Department of Microbiology, Bioscience Institute, National University of Ireland, Cork, Ireland.
authors: Pablo
authors: P
authors: Alvarez-Martin
authors: Mary
authors: M
authors: O'Connell Motherway
authors: Francesca
authors: F
authors: Turroni
authors: Elena
authors: E
authors: Foroni
authors: Marco
authors: M
authors: Ventura
authors: Douwe
authors: D
authors: van Sinderen
mesh_terms: D001644:Bifidobacterium / Q000235:genetics* / Q000378:metabolism*; D001665:Binding Sites; D004252:DNA Mutational Analysis; D004269:DNA, Bacterial / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D017930:Genes, Reporter; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D015843:Serpins / Q000235:genetics / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism; D014158:Transcription, Genetic
chemical_list: D004269:DNA, Bacterial; D015843:Serpins; D014157:Transcription Factors