title: ManA is regulated by RssAB signaling and promotes motility in Serratia marcescens.
abstract: Serratia marcescens swarms on 0.8% LB agar at 30 °C but not at 37 °C. To understand the molecular mechanism regulating Serratia swarming, transposon mutagenesis was performed to screen for mutants that swarmed at 37 °C. In one mutant, S. marcescens WW100, the transposon was inserted in the upstream region of manA, which encodes mannose-6-phosphate isomerase, a type I phosphomannose isomerase. The transcriptional and translational levels of manA were higher in S. marcescens WW100 than in the wild-type strain. S. marcescens WW100 produced more serrawettin W1 (biosurfactant) than the wild-type, as detected by thin-layer chromatography, to promote surface motility by reducing surface tension. Serratia swarming was previously shown to be negatively regulated by the RssA-RssB two-component system. An electrophoretic mobility shift assay (EMSA) indicated that phosphorylated RssB (the response regulator) binds upstream of the transposon insertion site and manA in S. marcescens WW100. Analysis by real-time RT-PCR (qRT-PCR) revealed that, compared to the wild-type level, manA mRNA was increased in the rssA deletion mutant. The results indicated that RssA-RssB signaling directly represses the expression of manA and that overexpression of manA increases the production of serrawettin for Serratia swarming at 37 °C.
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, College of Medicine, 701 Section 3, Chung Yang Road, Hualien 970, Taiwan, ROC. Electronic address: pcsoo@mail.tcu.edu.tw.
authors.forename: Po-Chi
authors.initials: PC
authors.lastname: Soo
authors.affiliation: Department of Laboratory Medicine and Biotechnology, Tzu Chi University, College of Medicine, 701 Section 3, Chung Yang Road, Hualien 970, Taiwan, ROC. Electronic address: d92424001@ntu.edu.tw.
authors.forename: Yu-Tze
authors.initials: YT
authors.lastname: Horng
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, No. 1, Chang-Te St., Taipei 100, Taiwan, ROC. Electronic address: mnzno2@yahoo.com.tw.
authors.forename: Yung-Lin
authors.initials: YL
authors.lastname: Chang
authors.affiliation: Department of Clinical Laboratory Sciences and Medical Biotechnology, National Taiwan University College of Medicine, No. 1, Chang-Te St., Taipei 100, Taiwan, ROC. Electronic address: d91424001@ntu.edu.tw.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Tsai
authors.affiliation: University Center for Bioscience and Biotechnology, National Cheng Kung University, No. 1, University Road, Tainan City 701, Taiwan, ROC. Electronic address: wyjeng@mail.ncku.edu.tw.
authors.forename: Wen-Yih
authors.initials: WY
authors.lastname: Jeng
authors.affiliation: Department of Respiratory Therapy, College of Medicine, Fu Jen Catholic University, No. 510, Zhongzheng Road, Xinzhung Dist., New Taipei City 24205, Taiwan, ROC. Electronic address: 082385@mail.fju.edu.tw.
authors.forename: Chia-Chen
authors.initials: CC
authors.lastname: Lu
authors.affiliation: Department of Medical Biotechnology and Laboratory Science, and Research Center for Pathogenic Bacteria, Chang Gung University, No. 259, Wen-Hwa 1st Road, Kwei-Shan, Tao-Yuan 333, Taiwan, ROC. Electronic address: hclai@mail.cgu.edu.tw.
authors.forename: Hsin-Chih
authors.initials: HC
authors.lastname: Lai
mesh_terms: D001426:Bacterial Proteins / Q000378:metabolism*; D001483:Base Sequence; D001665:Binding Sites; D004251:DNA Transposable Elements; D015964:Gene Expression Regulation, Bacterial; D005947:Glucose / Q000378:metabolism; D008358:Mannose / Q000378:metabolism; D008359:Mannose-6-Phosphate Isomerase / Q000235:genetics / Q000378:metabolism*; D053858:Metabolic Networks and Pathways; D008969:Molecular Sequence Data; D016296:Mutagenesis; D011485:Protein Binding; D012706:Serratia marcescens / Q000502:physiology*; D015398:Signal Transduction
chemical_list: D001426:Bacterial Proteins; D004251:DNA Transposable Elements; D008359:Mannose-6-Phosphate Isomerase; D005947:Glucose; D008358:Mannose
keywords: Phosphomannose isomerase; Serratia marcescens; Swarming; Two-component system