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Muñoz-Bucio A, Arellano-Reynoso B, Sangari FJ, Sieira R, Thébault P, Espitia C, García Lobo JM, Seoane A, Suárez-Güemes F. Increased Brucella abortus asRNA_0067 expression under intraphagocytic stressors is associated with enhanced virB2 transcription. Arch Microbiol 2024; 206:285. [PMID: 38816572 PMCID: PMC11139718 DOI: 10.1007/s00203-024-03984-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2024] [Accepted: 04/27/2024] [Indexed: 06/01/2024]
Abstract
Intracellular pathogens like Brucella face challenges during the intraphagocytic adaptation phase, where the modulation of gene expression plays an essential role in taking advantage of stressors to persist inside the host cell. This study aims to explore the expression of antisense virB2 RNA strand and related genes under intracellular simulation media. Sense and antisense virB2 RNA strands increased expression when nutrient deprivation and acidification were higher, being starvation more determinative. Meanwhile, bspB, one of the T4SS effector genes, exhibited the highest expression during the exposition to pH 4.5 and nutrient abundance. Based on RNA-seq analysis and RACE data, we constructed a regional map depicting the 5' and 3' ends of virB2 and the cis-encoded asRNA_0067. Without affecting the CDS or a possible autonomous RBS, we generate the deletion mutant ΔasRNA_0067, significantly reducing virB2 mRNA expression and survival rate. These results suggest that the antisense asRNA_0067 expression is promoted under exposure to the intraphagocytic adaptation phase stressors, and its deletion is associated with a lower transcription of the virB2 gene. Our findings illuminate the significance of these RNA strands in modulating the survival strategy of Brucella within the host and emphasize the role of nutrient deprivation in gene expression.
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Affiliation(s)
- Adrian Muñoz-Bucio
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Microbiología e Inmunología. Circuito Exterior S/N, Universidad Nacional Autónoma de México, CDMX, Ciudad Universitaria, Coyoacán, 04510, Mexico
| | - Beatriz Arellano-Reynoso
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Microbiología e Inmunología. Circuito Exterior S/N, Universidad Nacional Autónoma de México, CDMX, Ciudad Universitaria, Coyoacán, 04510, Mexico
| | - Félix J Sangari
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC-SODERCAN, C. Albert Einstein 22, 39011, Santander, Cantabria, Spain
| | - Rodrigo Sieira
- Fundación Instituto Leloir-IIBBA CONICET, Av. Patricias Argentinas 435CABA, CP. 1405, Buenos Aires Argentina, Argentina
| | - Patricia Thébault
- Laboratoire Bordelais de Recherche en Informatique (LaBRI), UMR 5800, CNRS, Bordeaux INP, Université de Bordeaux, 33400, Talence, France
| | - Clara Espitia
- Departamento de Inmunología, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México MX, CDMX, Circuito Escolar 33, Ciudad Universitaria, Coyoacán, 04510, Mexico
| | - Juan M García Lobo
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC-SODERCAN, C. Albert Einstein 22, 39011, Santander, Cantabria, Spain
| | - Asunción Seoane
- Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria-CSIC-SODERCAN, C. Albert Einstein 22, 39011, Santander, Cantabria, Spain
| | - Francisco Suárez-Güemes
- Facultad de Medicina Veterinaria y Zootecnia, Departamento de Microbiología e Inmunología. Circuito Exterior S/N, Universidad Nacional Autónoma de México, CDMX, Ciudad Universitaria, Coyoacán, 04510, Mexico.
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Rosana ARR, Whitford DS, Migur A, Steglich C, Kujat-Choy SL, Hess WR, Owttrim GW. RNA helicase-regulated processing of the Synechocystis rimO-crhR operon results in differential cistron expression and accumulation of two sRNAs. J Biol Chem 2020; 295:6372-6386. [PMID: 32209657 DOI: 10.1074/jbc.ra120.013148] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 03/19/2020] [Indexed: 12/21/2022] Open
Abstract
The arrangement of functionally-related genes in operons is a fundamental element of how genetic information is organized in prokaryotes. This organization ensures coordinated gene expression by co-transcription. Often, however, alternative genetic responses to specific stress conditions demand the discoordination of operon expression. During cold temperature stress, accumulation of the gene encoding the sole Asp-Glu-Ala-Asp (DEAD)-box RNA helicase in Synechocystis sp. PCC 6803, crhR (slr0083), increases 15-fold. Here, we show that crhR is expressed from a dicistronic operon with the methylthiotransferase rimO/miaB (slr0082) gene, followed by rapid processing of the operon transcript into two monocistronic mRNAs. This cleavage event is required for and results in destabilization of the rimO transcript. Results from secondary structure modeling and analysis of RNase E cleavage of the rimO-crhR transcript in vitro suggested that CrhR plays a role in enhancing the rate of the processing in an auto-regulatory manner. Moreover, two putative small RNAs are generated from additional processing, degradation, or both of the rimO transcript. These results suggest a role for the bacterial RNA helicase CrhR in RNase E-dependent mRNA processing in Synechocystis and expand the known range of organisms possessing small RNAs derived from processing of mRNA transcripts.
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Affiliation(s)
- Albert Remus R Rosana
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Denise S Whitford
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Anzhela Migur
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
| | - Claudia Steglich
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany
| | - Sonya L Kujat-Choy
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Wolfgang R Hess
- Faculty of Biology, University of Freiburg, Schänzlestrasse 1, D-79104 Freiburg, Germany.,Freiburg Institute for Advanced Studies, University of Freiburg, Albertstrasse 19, D-79104 Freiburg, Germany
| | - George W Owttrim
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
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Sun WSW, Chen JW, Wu YC, Tsai HY, Kuo YL, Syu WJ. Expression Regulation of Polycistronic lee3 Genes of Enterohaemorrhagic Escherichia coli. PLoS One 2016; 11:e0155578. [PMID: 27182989 PMCID: PMC4868261 DOI: 10.1371/journal.pone.0155578] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2015] [Accepted: 05/01/2016] [Indexed: 01/21/2023] Open
Abstract
Enterohaemorrhagic Escherichia coli O157:H7 (EHEC) carries a pathogenic island LEE that is consisted mainly of five polycistronic operons. In the lee3 operon, mpc is the first gene and has been reported to down regulate the type-3 secretion system of EHEC when its gene product is over-expressed. Furthermore, mpc has been suggested to have a regulation function via translation but the mechanism remains unclear. To clarify this hypothesis, we dissected the polycistron and examined the translated products. We conclude that translation of mpc detrimentally governs the translation of the second gene, escV, which in turn affects the translation of the third gene, escN. Then sequentially, escN affects the expression of the downstream genes. Furthermore, we located a critical cis element within the mpc open-reading frame that plays a negative role in the translation-dependent regulation of lee3. Using qRT-PCR, we found that the amount of mpc RNA transcript present in EHEC was relatively limited when compared to any other genes within lee3. Taken together, when the transcription of LEE is activated, expression of mpc is tightly controlled by a restriction of the RNA transcript of mpc, translation of which is then critical for the efficient production of the operon’s downstream gene products.
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Affiliation(s)
- Wei-Sheng W. Sun
- Institute of Biochemistry and Molecular Biology, National Yang-Ming University, Taipei, Taiwan, R.O.C
- Taiwan International Graduate Program in Molecular Medicine, Academia Sinica, Taipei, Taiwan, R.O.C
| | - Jenn-Wei Chen
- Department of Microbiology and Immunology, National Cheng-Kung University, Tainan, Taiwan, R.O.C
| | - Yi-Chih Wu
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Hsing-Yuan Tsai
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, R.O.C
| | - Yu-Liang Kuo
- Department of Medical Imaging and Radiological Sciences, Chung Shan Medical University, Taichung, Taiwan, R.O.C
- Department of Medical Imaging, Chung Shan Medical University Hospital, Taichung, Taiwan, R.O.C
| | - Wan-Jr Syu
- Taiwan International Graduate Program in Molecular Medicine, Academia Sinica, Taipei, Taiwan, R.O.C
- Institute of Microbiology and Immunology, National Yang-Ming University, Taipei, Taiwan, R.O.C
- * E-mail:
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Tipton KA, Coleman JP, Pesci EC. Post-transcriptional regulation of gene PA5507 controls Pseudomonas quinolone signal concentration in P. aeruginosa. Mol Microbiol 2015; 96:670-83. [PMID: 25662317 DOI: 10.1111/mmi.12963] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/04/2015] [Indexed: 11/29/2022]
Abstract
Pseudomonas aeruginosa can sense and respond to a myriad of environmental signals and utilizes a system of small molecules to communicate through intercellular signaling. The small molecule 2-heptyl-3-hydroxy-4-quinolone (Pseudomonas Quinolone Signal [PQS]) is one of these signals and its synthesis is important for virulence. Previously, we identified an RpiR-type transcriptional regulator, QapR, that positively affects PQS production by repressing the qapR operon. An in-frame deletion of this regulator caused P. aeruginosa to produce a greatly reduced concentration of PQS. Here, we report that QapR translation is linked to the downstream gene PA5507. We found that introduction of a premature stop codon within qapR eliminates transcriptional autorepression of the qapR operon as expected but has no effect on PQS concentration. This was investigated with a series of lacZ reporter fusions which showed that translation of QapR must terminate at, or close to, the native qapR stop codon in order for translation of PA5507 to occur. Also, it was shown that truncation of the 5' end of the qapR transcript permitted PA5507 translation without translation of QapR. Our findings led us to conclude that PA5507 transcription and translation are both tightly controlled by QapR and this control is important for PQS homeostasis.
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Affiliation(s)
- Kyle A Tipton
- Department of Microbiology and Immunology, The Brody School of Medicine at East Carolina University, 600 Moye Blvd., Greenville, North Carolina, 27834, USA
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Juhas M. Type IV secretion systems and genomic islands-mediated horizontal gene transfer in Pseudomonas and Haemophilus. Microbiol Res 2014; 170:10-7. [PMID: 25183653 DOI: 10.1016/j.micres.2014.06.007] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2014] [Revised: 06/28/2014] [Accepted: 06/30/2014] [Indexed: 11/16/2022]
Abstract
Bacterial secretion systems, such as type IV secretion systems (T4SSs) are multi-subunit machines transferring macromolecules across membranes. Besides proteins, T4SSs also transfer nucleoprotein complexes, thus having a significant impact on the evolution of bacterial species. By T4SS-mediated horizontal gene transfer bacteria can acquire a broad spectrum of fitness genes allowing them to thrive in the wide variety of environments. Furthermore, acquisition of antibiotic-resistance and virulence genes can lead to the emergence of novel 'superbugs'. This review provides an update on the investigation of T4SSs. It highlights the role T4SSs play in the horizontal gene transfer, particularly in the evolution of catabolic pathways, antibiotic-resistance and virulence in Haemophilus and Pseudomonas.
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Affiliation(s)
- Mario Juhas
- Department of Pathology, University of Cambridge, Tennis Court Road, CB2 1QP Cambridge, UK.
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