1
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Matsuoka S, Shimizu Y, Nobe K, Matsumoto K, Asai K, Hara H. Glucolipids and lipoteichoic acids affect the activity of SigI, an alternative sigma factor, and WalKR, an essential two-component system, in Bacillus subtilis. Genes Cells 2021; 27:77-92. [PMID: 34910349 DOI: 10.1111/gtc.12912] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2021] [Revised: 12/09/2021] [Accepted: 12/10/2021] [Indexed: 11/29/2022]
Abstract
In a Bacillus subtilis ugtP mutant lacking glucolipids, SigI was activated in the log phase, and the activation of SigI in the mutant was suppressed by the expression of native ugtP. By contrast, SigI was inhibited in a yfnI mutant lacking one of the lipoteichoic acid (LTA) synthase genes, and the inhibition was suppressed by the expression of yfnI. A series of mutation analyses of the sigI promoter revealed that the two WalR binding sites were involved in the increase of PsigI -lacZ activity in the ugtP mutant and decrease of the lacZ activity in the yfnI mutant. Transcription from the SigI recognition sequence was enhanced in the ugtP mutant, whereas yfnI disruption inhibited the transcription from the SigA recognition sequence in the sigI promoter. We found that not only SigI but also WalKR, the essential two-component system, was activated in the ugtP mutant and inhibited in the yfnI mutant. The walK mutants with activated WalR exhibited abnormal morphology, but this phenotype was suppressed by the addition of MgSO4 . We conclude that glucolipids and LTA are key compounds in the maintenance of normal cell surface structure in B. subtilis.
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Affiliation(s)
- Satoshi Matsuoka
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Yoko Shimizu
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Kaori Nobe
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Kouji Matsumoto
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
| | - Kei Asai
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan.,Department of Bioscience, Faculty of Life Science, Tokyo University of Agriculture, Tokyo, Japan
| | - Hiroshi Hara
- Department of Biochemistry and Molecular Biology, Graduate School of Science and Engineering, Saitama University, Saitama, Japan
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2
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Rodríguez S, Correa-Galeote D, Sánchez-Pérez M, Ramírez M, Isidra-Arellano MC, Reyero-Saavedra MDR, Zamorano-Sánchez D, Hernández G, Valdés-López O, Girard L. A Novel OmpR-Type Response Regulator Controls Multiple Stages of the Rhizobium etli - Phaseolus vulgaris N 2-Fixing Symbiosis. Front Microbiol 2021; 11:615775. [PMID: 33384681 PMCID: PMC7769827 DOI: 10.3389/fmicb.2020.615775] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 11/26/2020] [Indexed: 11/22/2022] Open
Abstract
OmpR, is one of the best characterized response regulators families, which includes transcriptional regulators with a variety of physiological roles including the control of symbiotic nitrogen fixation (SNF). The Rhizobium etli CE3 genome encodes 18 OmpR-type regulators; the function of the majority of these regulators during the SNF in common bean, remains elusive. In this work, we demonstrated that a R. etli mutant strain lacking the OmpR-type regulator RetPC57 (ΔRetPC57), formed less nodules when used as inoculum for common bean. Furthermore, we observed reduced expression level of bacterial genes involved in Nod Factors production (nodA and nodB) and of plant early-nodulation genes (NSP2, NIN, NF-YA and ENOD40), in plants inoculated with ΔRetPC57. RetPC57 also contributes to the appropriate expression of genes which products are part of the multidrug efflux pumps family (MDR). Interestingly, nodules elicited by ΔRetPC57 showed increased expression of genes relevant for Carbon/Nitrogen nodule metabolism (PEPC and GOGAT) and ΔRetPC57 bacteroids showed higher nitrogen fixation activity as well as increased expression of key genes directly involved in SNF (hfixL, fixKf, fnrN, fixN, nifA and nifH). Taken together, our data show that the previously uncharacterized regulator RetPC57 is a key player in the development of the R. etli - P. vulgaris symbiosis.
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Affiliation(s)
- Susana Rodríguez
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - David Correa-Galeote
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mishael Sánchez-Pérez
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico.,Programa de Genómica Computacional, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mario Ramírez
- Programa de Genómica Funcional de Eucariontes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Mariel C Isidra-Arellano
- Laboratorio de Genómica Funcional de Leguminosas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla de Baz, Mexico
| | - María Del Rocío Reyero-Saavedra
- Laboratorio de Genómica Funcional de Leguminosas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla de Baz, Mexico
| | - David Zamorano-Sánchez
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Georgina Hernández
- Programa de Genómica Funcional de Eucariontes, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
| | - Oswaldo Valdés-López
- Laboratorio de Genómica Funcional de Leguminosas, Facultad de Estudios Superiores Iztacala, Universidad Nacional Autónoma de México, Tlalnepantla de Baz, Mexico
| | - Lourdes Girard
- Programa de Biología de Sistemas y Biología Sintética, Centro de Ciencias Genómicas, Universidad Nacional Autónoma de México, Cuernavaca, Mexico
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3
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Patel Y, Zhao H, Helmann JD. A regulatory pathway that selectively up-regulates elongasome function in the absence of class A PBPs. eLife 2020; 9:57902. [PMID: 32897856 PMCID: PMC7478892 DOI: 10.7554/elife.57902] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 08/22/2020] [Indexed: 12/28/2022] Open
Abstract
Bacteria surround themselves with peptidoglycan, an adaptable enclosure that contributes to cell shape and stability. Peptidoglycan assembly relies on penicillin-binding proteins (PBPs) acting in concert with SEDS-family transglycosylases RodA and FtsW, which support cell elongation and division respectively. In Bacillus subtilis, cells lacking all four PBPs with transglycosylase activity (aPBPs) are viable. Here, we show that the alternative sigma factor σI is essential in the absence of aPBPs. Defects in aPBP-dependent wall synthesis are compensated by σI-dependent upregulation of an MreB homolog, MreBH, which localizes the LytE autolysin to the RodA-containing elongasome complex. Suppressor analysis reveals that cells unable to activate this σI stress response acquire gain-of-function mutations in the essential histidine kinase WalK, which also elevates expression of sigI, mreBH and lytE. These results reveal compensatory mechanisms that balance the directional peptidoglycan synthesis arising from the elongasome complex with the more diffusive action of aPBPs.
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Affiliation(s)
- Yesha Patel
- Department of Microbiology, Cornell University, Ithaca, United States
| | - Heng Zhao
- Department of Microbiology, Cornell University, Ithaca, United States
| | - John D Helmann
- Department of Microbiology, Cornell University, Ithaca, United States
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4
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Liu H, Wang S, Song L, Yuan H, Liu K, Meng W, Wang T. Trehalose Production Using Recombinant Trehalose Synthase in Bacillus subtilis by Integrating Fermentation and Biocatalysis. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2019; 67:9314-9324. [PMID: 31352776 DOI: 10.1021/acs.jafc.9b03402] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Trehalose, a stable nonreducing disaccharide, protects biomolecules against environmental stress. However, trehalose production using secretory trehalose synthase (TreS) by Bacillus subtilis has not been well studied. In this study, a mutant TreS was successfully secreted and expressed in B. subtilis WB800N. The extracellular enzyme activity of TreS regulated by the P43 promoter and SPPhoD signal peptide in recombinant B. subtilis WB800N reached 23080.6 ± 1119.4 U/L in a 5-L fermenter after optimizing the culture medium, while xpF, skfA, lytC, and sdpC were knocked out. To reduce maltose consumption, malP and amyE corresponding to maltose transporters were further deleted. To simplify the trehalose production process, we invented a fermentation-coupling biocatalysis process involving recombinant bacteria fermentation to secrete TreS and simultaneous conversion of maltose to trehalose by TreS and found that the conversion rate of maltose to trehalose reached 75.5%, suggesting that this is an efficient strategy for large-scale trehalose production using recombinant B. subtilis.
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Affiliation(s)
- Hongling Liu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Song Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Longxiang Song
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Haibo Yuan
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Kaiquan Liu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Wu Meng
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
| | - Tengfei Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP) , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
- Key Laboratory of Shandong Microbial Engineering, School of Bioengineering , Qilu University of Technology (Shandong Academy of Sciences) , Jinan , Shandong 250353 , People's Republic of China
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5
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Wu X, Song Q, Han A. Interacting proteins of the essential two-component system YycFG in Bacillus subtilis. J Basic Microbiol 2019; 59:950-959. [PMID: 31339578 DOI: 10.1002/jobm.201800701] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/14/2019] [Accepted: 06/24/2019] [Indexed: 11/06/2022]
Abstract
Two-component signal transduction systems (TCSs) play a major role in adaption and survival of microorganisms in a dynamic and sometimes dangerous environment. YycFG is an essential TCS for many Gram-positive bacteria, such as Bacillus subtilis, which regulates many important biological processes. However, its functional essentiality remains largely unknown. Here, we report several YycFG interacting proteins through coimmunoprecipitation (Co-IP) and mass spectrometry (MS) analyses. We engineered the B. subtilis genome by a knock-in approach to express YycG with a C-terminal Flag and YycF with an N-terminal HA tag. Immunoprecipitated fractions using anti-Flag or anti-HA agarose were subjected to MS analyses. A total of 41 YycG interacting proteins and four YycF interacting proteins were identified, most of which are involved in cellular metabolic processes, including cell wall synthesis and modification. The interactions of YycG with AsnB and FabL, as examples, were further validated in vitro. This study provided a clue that YycFG may be directly involved in regulation of bacterial central metabolic pathways.
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Affiliation(s)
- Xuanang Wu
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Qi Song
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
| | - Aidong Han
- State Key Laboratory for Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiang'an, Xiamen, China
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6
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Liu H, Wang X, Yang S, Wang R, Wang T. Saturation mutagenesis and self-inducible expression of trehalose synthase in Bacillus subtilis. Biotechnol Prog 2019; 35:e2826. [PMID: 31021505 DOI: 10.1002/btpr.2826] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2018] [Revised: 02/12/2019] [Accepted: 04/19/2019] [Indexed: 01/27/2023]
Abstract
Trehalose is a nonreducing disaccharide synthesized by trehalose synthase (TreS), which catalyzes the reversible interconversion of maltose and trehalose. We aimed to enhance the catalytic conversion of maltose to trehalose by saturation mutagenesis, and constructed a self-inducible TreS expression system by generating a robust Bacillus subtilis recombinant. We found that the conversion yield and enzymatic activity of TreS was enhanced by saturation mutations, especially by the combination of V407M and K490L mutations. At the same time, these saturation mutations were contributing to reducing by-products in the reaction. Compared to WT TreS, the conversion yield of maltose to trehalose was increased by 11.9%, and the kcat /Km toward trehalose was 1.33 times higher in the reaction catalyzed by treSV407M-K490L . treSV407M-K490L expression was further observed in the recombinant B. subtilis W800N(ΔσF ) under the influence of PsrfA , Pcry3Aa , and PsrfA-cry3Aa promoters without an inducer. It was shown that PsrfA-cry3Aa was evidently a stronger promoter for treSV407M-K490L expression, with the intracellular enzymatic activity of recombinant treSV407M-K490L being over 5,800 U/g at 35 hr in TB medium. These results suggested the combination of two mutations, V407M and K490L, was conducive for the production of trehalose. In addition, the self-inducible TreSV407M/K490L mutant in the B. subtilis host provides a low-cost choice for the industrial production of endotoxin-free trehalose with high yields.
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Affiliation(s)
- Hongling Liu
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, QiLu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Industrial Fermentation Microbiology (Tianjin University of Science &Technology), Ministry of Education, Tianjin, People's Republic of China
| | - Xihui Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, QiLu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China
| | - Shaojie Yang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, QiLu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China
| | - Ruiming Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, QiLu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China
| | - Tengfei Wang
- State Key Laboratory of Biobased Material and Green Papermaking (LBMP), Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China.,Key Laboratory of Shandong Microbial Engineering, School of Bioengineering, QiLu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, People's Republic of China
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7
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Ramaniuk O, Převorovský M, Pospíšil J, Vítovská D, Kofroňová O, Benada O, Schwarz M, Šanderová H, Hnilicová J, Krásný L. σ I from Bacillus subtilis: Impact on Gene Expression and Characterization of σ I-Dependent Transcription That Requires New Types of Promoters with Extended -35 and -10 Elements. J Bacteriol 2018; 200:e00251-18. [PMID: 29914988 PMCID: PMC6088155 DOI: 10.1128/jb.00251-18] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 06/09/2018] [Indexed: 11/20/2022] Open
Abstract
The σI sigma factor from Bacillus subtilis is a σ factor associated with RNA polymerase (RNAP) that was previously implicated in adaptation of the cell to elevated temperature. Here, we provide a comprehensive characterization of this transcriptional regulator. By transcriptome sequencing (RNA-seq) of wild-type (wt) and σI-null strains at 37°C and 52°C, we identified ∼130 genes affected by the absence of σI Further analysis revealed that the majority of these genes were affected indirectly by σI The σI regulon, i.e., the genes directly regulated by σI, consists of 16 genes, of which eight (the dhb and yku operons) are involved in iron metabolism. The involvement of σI in iron metabolism was confirmed phenotypically. Next, we set up an in vitro transcription system and defined and experimentally validated the promoter sequence logo that, in addition to -35 and -10 regions, also contains extended -35 and -10 motifs. Thus, σI-dependent promoters are relatively information rich in comparison with most other promoters. In summary, this study supplies information about the least-explored σ factor from the industrially important model organism B. subtilisIMPORTANCE In bacteria, σ factors are essential for transcription initiation. Knowledge about their regulons (i.e., genes transcribed from promoters dependent on these σ factors) is the key for understanding how bacteria cope with the changing environment and could be instrumental for biotechnologically motivated rewiring of gene expression. Here, we characterize the σI regulon from the industrially important model Gram-positive bacterium Bacillus subtilis We reveal that σI affects expression of ∼130 genes, of which 16 are directly regulated by σI, including genes encoding proteins involved in iron homeostasis. Detailed analysis of promoter elements then identifies unique sequences important for σI-dependent transcription. This study thus provides a comprehensive view on this underexplored component of the B. subtilis transcription machinery.
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Affiliation(s)
- Olga Ramaniuk
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
- Department of Genetics and Microbiology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Martin Převorovský
- Department of Cell Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jiří Pospíšil
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Dragana Vítovská
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Olga Kofroňová
- Laboratory of Molecular Structure Characterization, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Oldřich Benada
- Laboratory of Molecular Structure Characterization, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Marek Schwarz
- Laboratory of Bioinformatics, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Hana Šanderová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Jarmila Hnilicová
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
| | - Libor Krásný
- Laboratory of Microbial Genetics and Gene Expression, Institute of Microbiology of the Czech Academy of Sciences, Prague, Czech Republic
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8
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Liu TY, Chu SH, Shaw GC. Deletion of the cell wall peptidoglycan hydrolase gene cwlO or lytE severely impairs transformation efficiency in Bacillus subtilis. J GEN APPL MICROBIOL 2018; 64:139-144. [PMID: 29553055 DOI: 10.2323/jgam.2017.09.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Tai-Yen Liu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
| | - Shu-Hung Chu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
| | - Gwo-Chyuan Shaw
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
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9
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Takada H, Shiwa Y, Takino Y, Osaka N, Ueda S, Watanabe S, Chibazakura T, Su'etsugu M, Utsumi R, Yoshikawa H. Essentiality of WalRK for growth in Bacillus subtilis and its role during heat stress. MICROBIOLOGY-SGM 2018; 164:670-684. [PMID: 29465029 DOI: 10.1099/mic.0.000625] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
WalRK is an essential two-component signal transduction system that plays a central role in coordinating cell wall synthesis and cell growth in Bacillus subtilis. However, the physiological role of WalRK and its essentiality for growth have not been elucidated. We investigated the behaviour of WalRK during heat stress and its essentiality for cell proliferation. We determined that the inactivation of the walHI genes which encode the negative modulator of WalK, resulted in growth defects and eventual cell lysis at high temperatures. Screening of suppressor mutations revealed that the inactivation of LytE, an dl-endopeptidase, restored the growth of the ΔwalHI mutant at high temperatures. Suppressor mutations that reduced heat induction arising from the walRK regulon were also mapped to the walK ORF. Therefore, we hypothesized that overactivation of LytE affects the phenotype of the ΔwalHI mutant. This hypothesis was corroborated by the overexpression of the negative regulator of LytE, IseA and PdaC, which rescued the growth of the ΔwalHI mutant at high temperatures. Elucidating the cause of the temperature sensitivity of the ΔwalHI mutant could explain the essentiality of WalRK. We proved that the constitutive expression of lytE or cwlO using a synthetic promoter uncouples these expressions from WalRK, and renders WalRK nonessential in the pdaC and iseA mutant backgrounds. We propose that the essentiality of WalRK is derived from the coordination of cell wall metabolism with cell growth by regulating dl-endopeptidase activity under various growth conditions.
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Affiliation(s)
- Hiraku Takada
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan.,Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yuh Shiwa
- Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Yuta Takino
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Natsuki Osaka
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Shuhei Ueda
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University, 3327-204 Nakamachi, Nara-shi, Nara 631-8505, Japan
| | - Satoru Watanabe
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Taku Chibazakura
- Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
| | - Masayuki Su'etsugu
- Department of Life Science and Research Center for Life Science, College of Science, Rikkyo University, Toshima-ku, Tokyo 171-8501, Japan
| | - Ryutaro Utsumi
- Department of Advanced Bioscience, Graduate School of Agriculture, Kindai University, 3327-204 Nakamachi, Nara-shi, Nara 631-8505, Japan
| | - Hirofumi Yoshikawa
- Genome Research Center, NODAI Research Institute, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan.,Department of Bioscience, Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Setagaya-ku, Tokyo 156-8502, Japan
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10
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Liu TY, Chu SH, Hu YN, Wang JJ, Shaw GC. Genetic evidence that multiple proteases are involved in modulation of heat-induced activation of the sigma factor SigI in Bacillus subtilis. FEMS Microbiol Lett 2017; 364:3063884. [PMID: 28333276 DOI: 10.1093/femsle/fnx054] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Accepted: 03/07/2017] [Indexed: 11/13/2022] Open
Abstract
The Bacillus subtilis sigI-rsgI operon encodes the heat-inducible sigma factor SigI and its cognate anti-sigma factor RsgI. The heat-activated SigI positively regulates expression of sigI itself and genes involved in cell wall homeostasis and heat resistance. It remains unknown which protease(s) may contribute to degradation of RsgI and heat-induced activation of SigI. In this study, we found that transcription of sigI from its σI-dependent promoter under heat stress was downregulated in a strain lacking the heat-inducible sigma factor SigB. Deletion of protease-relevant clpP, clpC or rasP severely impaired sigI expression during heat stress, whereas deletion of clpE partially impaired sigI expression. Complementation of mutations with corresponding intact genes restored sigI expression. In a null mutant of rsgI, SigI was activated and sigI expression was strongly upregulated during normal growth and under heat stress. In this rsgI mutant, further inactivation of rasP or clpE did not affect sigI expression, whereas further inactivation of clpP or clpC severely or partially impaired sigI expression. Spx negatively influenced sigI expression during heat stress. Possible implications are discussed. Given that clpC, clpP and spx are directly regulated by SigB, SigB appears to control sigI expression under heat stress via ClpC, ClpP and Spx.
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Yang S, Du G, Chen J, Kang Z. Characterization and application of endogenous phase-dependent promoters in Bacillus subtilis. Appl Microbiol Biotechnol 2017; 101:4151-4161. [DOI: 10.1007/s00253-017-8142-7] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2016] [Revised: 01/05/2017] [Accepted: 01/20/2017] [Indexed: 01/01/2023]
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Mohedano ML, Amblar M, de la Fuente A, Wells JM, López P. The Response Regulator YycF Inhibits Expression of the Fatty Acid Biosynthesis Repressor FabT in Streptococcus pneumoniae. Front Microbiol 2016; 7:1326. [PMID: 27610104 PMCID: PMC4996995 DOI: 10.3389/fmicb.2016.01326] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2016] [Accepted: 08/11/2016] [Indexed: 11/25/2022] Open
Abstract
The YycFG (also known as WalRK, VicRK, MicAB, or TCS02) two-component system (TCS) is highly conserved among Gram-positive bacteria with a low G+C content. In Streptococcus pneumoniae the YycF response regulator has been reported to be essential due to its control of pcsB gene expression. Previously we showed that overexpression of yycF in S. pneumoniae TIGR4 altered the transcription of genes involved in cell wall metabolism and fatty acid biosynthesis, giving rise to anomalous cell division and increased chain length of membrane fatty acids. Here, we have overexpressed the yycFG system in TIGR4 wild-type strain and yycF in a TIGR4 mutant depleted of YycG, and analyzed their effects on expression of proteins involved in fatty acid biosynthesis during activation of the TCS. We demonstrate that transcription of the fab genes and levels of their products were only altered in the YycF overexpressing strain, indicating that the unphosphorylated form of YycF is involved in the regulation of fatty acid biosynthesis. In addition, DNA-binding assays and in vitro transcription experiments with purified YycF and the promoter region of the FabTH-acp operon support a direct inhibition of transcription of the FabT repressor by YycF, thus confirming the role of the unphosphorylated form in transcriptional regulation.
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Affiliation(s)
- Maria L Mohedano
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Mónica Amblar
- Unidad de Patología Molecular del Neumococo, Centro Nacional de Microbiología, Instituto de Salud Carlos III Majadahonda, Spain
| | - Alicia de la Fuente
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
| | - Jerry M Wells
- Host-Microbe Interactomics, Animal Sciences Department, University of Wageningen Wageningen, Netherlands
| | - Paloma López
- Laboratorio de Biología Molecular de Bacterias Gram positivas, Departamento de Microbiología Molecular y Biología de las Infecciones, Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas Madrid, Spain
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Teichoic Acid Polymers Affect Expression and Localization of dl-Endopeptidase LytE Required for Lateral Cell Wall Hydrolysis in Bacillus subtilis. J Bacteriol 2016; 198:1585-1594. [PMID: 27002131 DOI: 10.1128/jb.00003-16] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 03/14/2016] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED In Bacillus subtilis, the dl-endopeptidase LytE is responsible for lateral peptidoglycan hydrolysis during cell elongation. We found that σ(I)-dependent transcription of lytE is considerably enhanced in a strain with a mutation in ltaS, which encodes a major lipoteichoic acid (LTA) synthase. Similar enhancements were observed in mutants that affect the glycolipid anchor and wall teichoic acid (WTA) synthetic pathways. Immunofluorescence microscopy revealed that the LytE foci were considerably increased in these mutants. The localization patterns of LytE on the sidewalls appeared to be helix-like in LTA-defective or WTA-reduced cells and evenly distributed on WTA-depleted or -defective cell surfaces. These results strongly suggested that LTA and WTA affect both σ(I)-dependent expression and localization of LytE. Interestingly, increased LytE localization along the sidewall in the ltaS mutant largely occurred in an MreBH-independent manner. Moreover, we found that cell surface decorations with LTA and WTA are gradually reduced at increased culture temperatures and that LTA rather than WTA on the cell surface is reduced at high temperatures. In contrast, the amount of LytE on the cell surface gradually increased under heat stress conditions. Taken together, these results indicated that reductions in these anionic polymers at high temperatures might give rise to increases in SigI-dependent expression and cell surface localization of LytE at high temperatures. IMPORTANCE The bacterial cell wall is required for maintaining cell shape and bearing environmental stresses. The Gram-positive cell wall consists of mesh-like peptidoglycan and covalently linked wall teichoic acid and lipoteichoic acid polymers. It is important to determine if these anionic polymers are required for proliferation and environmental adaptation. Here, we demonstrated that these polymers affect the expression and localization of a peptidoglycan hydrolase LytE required for lateral cell wall elongation. Moreover, we found that cell surface decorations with teichoic acid polymers are substantially decreased at high temperatures and that the peptidoglycan hydrolase is consequently increased. These findings suggest that teichoic acid polymers control lateral peptidoglycan hydrolysis by LytE, and bacteria drastically change their cell wall content to adapt to their environment.
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Kim JGY, Wilson AC. Loss of σI affects heat-shock response and virulence gene expression in Bacillus anthracis. MICROBIOLOGY-SGM 2016; 162:564-574. [PMID: 26744224 DOI: 10.1099/mic.0.000236] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
The pathogenesis of Bacillus anthracis depends on several virulence factors, including the anthrax toxin. Loss of the alternative sigma factor σI results in a coordinate decrease in expression of all three toxin subunits. Our observations suggest that loss of σI alters the activity of the master virulence regulator AtxA, but atxA transcription is unaffected by loss of σI. σI-containing RNA polymerase does not appear to directly transcribe either atxA or the toxin gene pagA. As in Bacillus subtilis, loss of σI in B. anthracis results in increased sensitivity to heat shock and transcription of sigI, encoding σI, is induced by elevated temperature. Encoded immediately downstream of and part of a bicistronic message with sigI is an anti-sigma factor, RsgI, which controls σI activity. Loss of RsgI has no direct effect on virulence gene expression. sigI appears to be expressed from both the σI and σA promoters, and transcription from the σA promoter is likely more significant to virulence regulation. We propose a model in which σI can be induced in response to heat shock, whilst, independently, σI is produced under non-heat-shock, toxin-inducing conditions to indirectly regulate virulence gene expression.
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Affiliation(s)
- Jenny Gi Yae Kim
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA
| | - Adam C Wilson
- Department of Biology, Georgia State University, Atlanta, GA 30302, USA
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Shen YC, Hu YN, Shaw GC. Expressions of alkaline phosphatase genes during phosphate starvation are under positive influences of multiple cell wall hydrolase genes in Bacillus subtilis. J GEN APPL MICROBIOL 2016; 62:106-9. [DOI: 10.2323/jgam.62.106] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Yueh-Chi Shen
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
| | - Yi-Nei Hu
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
| | - Gwo-Chyuan Shaw
- Institute of Biochemistry and Molecular Biology, School of Life Sciences, National Yang-Ming University
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MreB-Dependent Inhibition of Cell Elongation during the Escape from Competence in Bacillus subtilis. PLoS Genet 2015; 11:e1005299. [PMID: 26091431 PMCID: PMC4474612 DOI: 10.1371/journal.pgen.1005299] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2015] [Accepted: 05/26/2015] [Indexed: 02/02/2023] Open
Abstract
During bacterial exponential growth, the morphogenetic actin-like MreB proteins form membrane-associated assemblies that move processively following trajectories perpendicular to the long axis of the cell. Such MreB structures are thought to scaffold and restrict the movement of peptidoglycan synthesizing machineries, thereby coordinating sidewall elongation. In Bacillus subtilis, this function is performed by the redundant action of three MreB isoforms, namely MreB, Mbl and MreBH. mreB and mbl are highly transcribed from vegetative promoters. We have found that their expression is maximal at the end of exponential phase, and rapidly decreases to a low basal level upon entering stationary phase. However, in cells developing genetic competence, a stationary phase physiological adaptation, expression of mreB was specifically reactivated by the central competence regulator ComK. In competent cells, MreB was found in complex with several competence proteins by in vitro pull-down assays. In addition, it co-localized with the polar clusters formed by the late competence peripheral protein ComGA, in a ComGA-dependent manner. ComGA has been shown to be essential for the inhibition of cell elongation characteristic of cells escaping the competence state. We show here that the pathway controlling this elongation inhibition also involves MreB. Our findings suggest that ComGA sequesters MreB to prevent cell elongation and therefore the escape from competence. In bacterial cells, like in their eukaryotic counterparts, precise spatiotemporal localization of proteins is critical for their cellular function. This study shows that the expression and the localization of the bacterial actin-like MreB protein are growth phase-dependent. During exponential growth, we previously showed that MreB, together with other morphogenetic factors, forms discrete assemblies that move in a directed manner along peripheral tracks. Here, we demonstrate that in cells that develop genetic competence during stationary phase, transcription of mreB is specifically activated and MreB relocalizes to the cell poles. Our findings suggest a model in which MreB sequestration by the late competence protein ComGA prevents cell elongation during the escape from competence.
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