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Garber AI, Sano EB, Gallagher AL, Miller SR. Duplicate Gene Expression and Possible Mechanisms of Paralog Retention During Bacterial Genome Expansion. Genome Biol Evol 2024; 16:evae089. [PMID: 38670115 PMCID: PMC11086944 DOI: 10.1093/gbe/evae089] [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: 11/09/2023] [Revised: 04/18/2024] [Accepted: 04/22/2024] [Indexed: 04/28/2024] Open
Abstract
Gene duplication contributes to the evolution of expression and the origin of new genes, but the relative importance of different patterns of duplicate gene expression and mechanisms of retention remains debated and particularly poorly understood in bacteria. Here, we investigated gene expression patterns for two lab strains of the cyanobacterium Acaryochloris marina with expanding genomes that contain about 10-fold more gene duplicates compared with most bacteria. Strikingly, we observed a generally stoichiometric pattern of greater combined duplicate transcript dosage with increased gene copy number, in contrast to the prevalence of expression reduction reported for many eukaryotes. We conclude that increased transcript dosage is likely an important mechanism of initial duplicate retention in these bacteria and may persist over long periods of evolutionary time. However, we also observed that paralog expression can diverge rapidly, including possible functional partitioning, for which different copies were respectively more highly expressed in at least one condition. Divergence may be promoted by the physical separation of most Acaryochloris duplicates on different genetic elements. In addition, expression pattern for ancestrally shared duplicates could differ between strains, emphasizing that duplicate expression fate need not be deterministic. We further observed evidence for context-dependent transcript dosage, where the aggregate expression of duplicates was either greater or lower than their single-copy homolog depending on physiological state. Finally, we illustrate how these different expression patterns of duplicated genes impact Acaryochloris biology for the innovation of a novel light-harvesting apparatus and for the regulation of recA paralogs in response to environmental change.
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Affiliation(s)
- Arkadiy I Garber
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Emiko B Sano
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Amy L Gallagher
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
| | - Scott R Miller
- Division of Biological Sciences, University of Montana, Missoula, MT 59812, USA
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Cai N, Luo W, Ding L, Chen L, Huang Y. Obesity-related indicators and tuberculosis: A Mendelian randomization study. PLoS One 2024; 19:e0297905. [PMID: 38557966 PMCID: PMC10984409 DOI: 10.1371/journal.pone.0297905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 01/15/2024] [Indexed: 04/04/2024] Open
Abstract
PURPOSE Obesity is a strong risk factor for many diseases, with controversy regarding the cause(s) of tuberculosis (TB) reflected by contradictory findings. Therefore, a larger sample population is required to determine the relationship between obesity and TB, which may further inform treatment. METHODS Obesity-related indicators and TB mutation data were obtained from a genome-wide association study database, while representative instrumental variables (IVs) were obtained by screening and merging. Causal relationships between exposure factors and outcomes were determined using two-sample Mendelian randomization (MR) analysis. Three tests were used to determine the representativeness and stability of the IVs, supported by sensitivity analysis. RESULTS Initially, 191 single nucleotide polymorphisms were designated as IVs by screening, followed by two-sample MR analysis, which revealed the causal relationship between waist circumference [odds ratio (OR): 2.13 (95% confidence interval (CI): 1.19-3.80); p = 0.011] and TB. Sensitivity analysis verified the credibility of the IVs, none of which were heterogeneous or horizontally pleiotropic. CONCLUSION The present study determined the causal effect between waist circumference and TB by two-sample MR analysis and found both to be likely to be potential risk factors.
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Affiliation(s)
- Nuannuan Cai
- Pulmonary and Critical Care Medicine, Hainan Provincial People’s Hospital, Haikou, Hainan, China
| | - Weiyan Luo
- Pulmonary and Critical Care Medicine, Hainan Provincial People’s Hospital, Haikou, Hainan, China
| | - Lili Ding
- Pulmonary and Critical Care Medicine, Hainan Provincial People’s Hospital, Haikou, Hainan, China
| | - Lijin Chen
- Pulmonary and Critical Care Medicine, Hainan Provincial People’s Hospital, Haikou, Hainan, China
| | - Yuanjiang Huang
- Infectious and Tropical Disease Dept (Tuberculosis), The Second Affiliated Hospital of Hainan Medical College, Haikou, Hainan, China
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Schwarz MGA, Corrêa PR, Mendonça-Lima L. Transcriptional Profiling of Homologous Recombination Pathway Genes in Mycobacterium bovis BCG Moreau. Microorganisms 2023; 11:2534. [PMID: 37894192 PMCID: PMC10609372 DOI: 10.3390/microorganisms11102534] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 08/17/2023] [Accepted: 08/29/2023] [Indexed: 10/29/2023] Open
Abstract
Mycobacterium bovis BCG Moreau is the main Brazilian strain for vaccination against tuberculosis. It is considered an early strain, more like the original BCG, whereas BCG Pasteur, largely used as a reference, belongs to the late strain clade. BCG Moreau, contrary to Pasteur, is naturally deficient in homologous recombination (HR). In this work, using a UV exposure test, we aimed to detect differences in the survival of various BCG strains after DNA damage. Transcription of core and regulatory HR genes was further analyzed using RT-qPCR, aiming to identify the molecular agent responsible for this phenotype. We show that early strains share the Moreau low survival rate after UV exposure, whereas late strains mimic the Pasteur phenotype, indicating that this increase in HR efficiency is linked to the evolutionary clade history. Additionally, RT-qPCR shows that BCG Moreau has an overall lower level of these transcripts than Pasteur, indicating a correlation between this gene expression profile and HR efficiency. Further assays should be performed to fully identify the molecular mechanism that may explain this differential phenotype between early and late BCG strains.
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Affiliation(s)
- Marcos Gustavo Araujo Schwarz
- Laboratório de Biologia Molecular Aplicada à Micobactérias, Instituto Oswaldo Cruz, Fiocruz, Rio de Janeiro 21040-900, RJ, Brazil; (P.R.C.); (L.M.-L.)
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Kiran K, Patil KN. Characterization of Staphylococcus aureus RecX protein: Molecular insights into negative regulation of RecA protein and implications in HR processes. J Biochem 2023; 174:227-237. [PMID: 37115499 DOI: 10.1093/jb/mvad039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Revised: 04/11/2023] [Accepted: 04/17/2023] [Indexed: 04/29/2023] Open
Abstract
Homologous recombination (HR) is essential for genome stability and for maintaining genetic diversity. In eubacteria, RecA protein plays a key role during DNA repair, transcription, and HR. RecA is regulated at multiple levels, but majorly by RecX protein. Moreover, studies have shown RecX is a potent inhibitor of RecA and thus acts as an antirecombinase. Staphylococcus aureus is a major food-borne pathogen that causes skin, bone joint, and bloodstream infections. To date, RecX's role in S. aureus has remained enigmatic. Here, we show that S. aureus RecX (SaRecX) is expressed during exposure to DNA-damaging agents, and purified RecX protein directly interacts physically with RecA protein. The SaRecX is competent to bind with single-stranded DNA preferentially and double-stranded DNA feebly. Significantly, SaRecX impedes the RecA-driven displacement loop and inhibits formation of the strand exchange. Notably, SaRecX also abrogates adenosine triphosphate hydrolysis and abolishes the LexA coprotease activity. These findings highlight the role of the RecX protein as an antirecombinase during HR and play a pivotal role in regulation of RecA during the DNA transactions.
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Affiliation(s)
- Kajal Kiran
- Department of Microbiology and Fermentation Technology, Council of Scientific and Industrial Research-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru 570 020, Karnataka, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
| | - K Neelakanteshwar Patil
- Department of Microbiology and Fermentation Technology, Council of Scientific and Industrial Research-Central Food Technological Research Institute (CSIR-CFTRI), Mysuru 570 020, Karnataka, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, Uttar Pradesh, India
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Jiang F, Mao Y, Lu B, Zhou G, Wang J. A hypoxia risk signature for the tumor immune microenvironment evaluation and prognosis prediction in acute myeloid leukemia. Sci Rep 2021; 11:14657. [PMID: 34282207 PMCID: PMC8289869 DOI: 10.1038/s41598-021-94128-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Accepted: 07/06/2021] [Indexed: 02/06/2023] Open
Abstract
Acute myeloid leukemia (AML) is the most prevalent form of acute leukemia. Patients with AML often have poor clinical prognoses. Hypoxia can activate a series of immunosuppressive processes in tumors, resulting in diseases and poor clinical prognoses. However, how to evaluate the severity of hypoxia in tumor immune microenvironment remains unknown. In this study, we downloaded the profiles of RNA sequence and clinicopathological data of pediatric AML patients from Therapeutically Applicable Research to Generate Effective Treatments (TARGET) database, as well as those of AML patients from Gene Expression Omnibus (GEO). In order to explore the immune microenvironment in AML, we established a risk signature to predict clinical prognosis. Our data showed that patients with high hypoxia risk score had shorter overall survival, indicating that higher hypoxia risk scores was significantly linked to immunosuppressive microenvironment in AML. Further analysis showed that the hypoxia could be used to serve as an independent prognostic indicator for AML patients. Moreover, we found gene sets enriched in high-risk AML group participated in the carcinogenesis. In summary, the established hypoxia-related risk model could act as an independent predictor for the clinical prognosis of AML, and also reflect the response intensity of the immune microenvironment in AML.
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Affiliation(s)
- Feng Jiang
- grid.8547.e0000 0001 0125 2443Department of Neonatology, Obstetrics and Gynecology Hospital, Fudan University, No. 419, Fangxie Road, Shanghai, 200011 China
| | - Yan Mao
- grid.412676.00000 0004 1799 0784Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Binbin Lu
- grid.412676.00000 0004 1799 0784Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Guoping Zhou
- grid.412676.00000 0004 1799 0784Department of Pediatrics, The First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029 China
| | - Jimei Wang
- grid.8547.e0000 0001 0125 2443Department of Neonatology, Obstetrics and Gynecology Hospital, Fudan University, No. 419, Fangxie Road, Shanghai, 200011 China
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Reedoy KS, Loots DT, Beukes D, Reenen MV, Pillay B, Pillay M. Mycobacterium tuberculosis curli pili (MTP) is associated with significant host metabolic pathways in an A549 epithelial cell infection model and contributes to the pathogenicity of Mycobacterium tuberculosis. Metabolomics 2020; 16:116. [PMID: 33084984 DOI: 10.1007/s11306-020-01736-5] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 10/02/2020] [Indexed: 12/13/2022]
Abstract
INTRODUCTION A clear understanding of the metabolome of Mycobacterium tuberculosis and its target host cell during infection is fundamental for the development of novel diagnostic tools, effective drugs and vaccines required to combat tuberculosis. The surface-located Mycobacterium tuberculosis curli pili (MTP) adhesin forms initial contact with the host cell and is therefore important for the establishment of infection. OBJECTIVE The aim of this investigation was to determine the role of MTP in modulating pathogen and host metabolic pathways in A549 epithelial cells infected with MTP proficient and deficient strains of M. tuberculosis. METHODS Uninfected A549 epithelial cells, and those infected with M. tuberculosis V9124 wild-type strain, Δmtp and the mtp-complemented strains, were subjected to metabolite extraction, two-dimensional gas chromatography time-of-flight mass spectrometry (GCxGC-TOFMS) and bioinformatic analyses. Univariate and multivariate statistical tests were used to identify metabolites that were significantly differentially produced in the WT-infected and ∆mtp-infected A549 epithelial cell models, comparatively. RESULTS A total of 46 metabolites occurred in significantly lower relative concentrations in the Δmtp-infected cells, indicating a reduction in nucleic acid synthesis, amino acid metabolism, glutathione metabolism, oxidative stress, lipid metabolism and peptidoglycan, compared to those cells infected with the WT strain. CONCLUSION The absence of MTP was associated with significant changes to the host metabolome, suggesting that this adhesin is an important contributor to the pathogenicity of M. tuberculosis, and supports previous findings of its potential as a suitable drug, vaccine and diagnostic target.
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Affiliation(s)
- K S Reedoy
- Medical Microbiology School of Laboratory Medicine and Medical Sciences, College of Health Sciences, Doris Duke Medical Research Institute, University of KwaZulu-Natal, 1st Floor, Congella, Private Bag 7, Durban, 4013, South Africa
| | - D T Loots
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag x6001, Box 269, Potchefstroom, 2531, South Africa
| | - D Beukes
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag x6001, Box 269, Potchefstroom, 2531, South Africa
| | - M van Reenen
- Human Metabolomics, Faculty of Natural and Agricultural Sciences, North-West University, Private Bag x6001, Box 269, Potchefstroom, 2531, South Africa
| | - B Pillay
- School of Life Sciences, College of Agriculture, Engineering and Science, University of KwaZulu-Natal, Westville Campus, Private Bag X54001, Durban, 4000, South Africa
| | - M Pillay
- Medical Microbiology School of Laboratory Medicine and Medical Sciences, College of Health Sciences, Doris Duke Medical Research Institute, University of KwaZulu-Natal, 1st Floor, Congella, Private Bag 7, Durban, 4013, South Africa.
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Prasad D, Muniyappa K. The extended N-terminus of Mycobacterium smegmatis RecX potentiates its ability to antagonize RecA functions. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2020; 1868:140468. [PMID: 32526474 DOI: 10.1016/j.bbapap.2020.140468] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 05/21/2020] [Accepted: 06/05/2020] [Indexed: 01/13/2023]
Abstract
The members of the RecX family of proteins have a unique capacity to regulate the catalytic activities of RecA/Rad51 proteins in both prokaryotic and eukaryotic organisms. However, our understanding of the functional roles of RecX in pathogenic and non-pathogenic mycobacteria has been limited by insufficient knowledge of the molecular mechanisms of its activity and regulation. Moreover, the significance of a unique 14 amino acid N-terminal extension in Mycobacterium smegmatis RecX (MsRecX) to its function remains unknown. Here, we advance our understanding of the antagonistic roles of mycobacterial RecX proteins and the functional significance of the extended N-terminus of MsRecX. The full-length MsRecX acts as an antagonist of RecA, negatively regulating RecA promoted functions, including DNA strand exchange, LexA cleavage and ATP hydrolysis, but not binding of ATP. The N-terminally truncated MsRecX variants retain the RecA inhibitory activity, albeit with lower efficiencies compared to the full-length protein. Perhaps most importantly, direct visualization of RecA nucleoprotein filaments, which had been incubated with RecX proteins, showed that they promote disassembly of nucleoprotein filaments primarily within the filaments. In addition, interaction of RecX proteins with the RecA nucleoprotein filaments results in the formation of stiff and irregularly shaped nucleoprotein filaments. Thus, these findings add an additional mechanism by which RecX disassembles RecA nucleoprotein filaments. Overall, this study provides strong evidence for the notion that the N-terminal 14 amino acid region of MsRecX plays an important role in the negative regulation of RecA functions and new insights into the molecular mechanism underlying RecX function.
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Affiliation(s)
- Deepika Prasad
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India
| | - Kalappa Muniyappa
- Department of Biochemistry, Indian Institute of Science, Bengaluru 560012, India.
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