title: Stationary-phase induction of vvpS expression by three transcription factors: repression by LeuO and activation by SmcR and CRP.
abstract: An exoprotease of Vibrio vulnificus, VvpS, exhibits an autolytic function during the stationary phase. To understand how vvpS expression is controlled, the regulators involved in vvpS transcription and their regulatory mechanisms were investigated. LeuO was isolated in a ligand-fishing experiment, and experiments using a leuO-deletion mutant revealed that LeuO represses vvpS transcription. LeuO bound the extended region including LeuO-binding site (LBS)-I and LBS-II. Further screening of additional regulators revealed that SmcR and cyclic adenosine monophosphate-receptor protein (CRP) play activating roles in vvpS transcription. SmcR and CRP bound the regions overlapping LBS-I and -II, respectively. In addition, the LeuO occupancy of LBS-I and LBS-II was competitively exchanged by SmcR and CRP, respectively. To examine the mechanism of stationary-phase induction of vvpS expression, in vivo levels of three transcription factors were monitored. Cellular level of LeuO was maximal at exponential phase, while those of SmcR and CRP were maximal at stationary phase and relatively constant after the early-exponential phase, respectively. Thus, vvpS transcription was not induced during the exponential phase by high cellular content of LeuO. When entering the stationary phase, however, LeuO content was significantly reduced and repression by LeuO was relieved through simultaneous binding of SmcR and CRP to LBS-I and -II, respectively.
authors: Department of Life Science, Sogang University, Seoul, 121-742, South Korea.
authors: Jeong-A
authors: JA
authors: Kim
authors: National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, 151-921, South Korea.
authors: Jin Hwan
authors: JH
authors: Park
authors: Department of Life Science, Sogang University, Seoul, 121-742, South Korea.
authors: Mi-Ae
authors: MA
authors: Lee
authors: Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
authors: Hyun-Jung
authors: HJ
authors: Lee
authors: Department of Environmental Medical Biology, Institute of Tropical Medicine, Brain Korea 21 PLUS Project for Medical Science, Yonsei University College of Medicine, Seoul, 120-752, South Korea.
authors: Soon-Jung
authors: SJ
authors: Park
authors: Department of Life Science, Sogang University, Seoul, 121-742, South Korea.
authors: Kun-Soo
authors: KS
authors: Kim
authors: National Research Laboratory of Molecular Microbiology and Toxicology, Department of Agricultural Biotechnology, Seoul National University, Seoul, 151-921, South Korea.
authors: Sang-Ho
authors: SH
authors: Choi
authors: Department of Life Science, Sogang University, Seoul, 121-742, South Korea.
authors: Kyu-Ho
authors: KH
authors: Lee
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism; D004790:Enzyme Induction; D020689:Exopeptidases / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D015964:Gene Expression Regulation, Bacterial; D015971:Gene Expression Regulation, Enzymologic; D011485:Protein Binding; D057057:Serine Proteases / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism*; D041261:Vibrio vulnificus / Q000201:enzymology / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D014157:Transcription Factors; D020689:Exopeptidases; D057057:Serine Proteases