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Kirdat K, Tiwarekar B, Manjula KN, Padma S, Sathe S, Sundararaj R, Yadav A. Draft genome sequence of ' Candidatus Phytoplasma asteris,' strain SW86 associated with sandal spike disease (SSD). 3 Biotech 2024; 14:109. [PMID: 38481824 PMCID: PMC10928027 DOI: 10.1007/s13205-024-03952-5] [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: 11/15/2022] [Accepted: 02/02/2024] [Indexed: 04/11/2024] Open
Abstract
The sandal spike disease (SSD), related to 'Ca. Phytoplasma asteris' (Aster Yellows group), poses a significant threat to Indian sandalwood (Santalum album L.), making it the second most expensive wood globally due to declining population density. The epidemiology of SSD and the nature of the pathogen remain poorly understood. The SW86 isolate, collected from the Marayoor Sandalwood Reserve, was chosen for genome sequencing subsequent to confirming its titer and enriching phytoplasma DNA. Genome sequencing, utilizing Illumina and Oxford Nanopore Technology platforms, enabled a targeted hybrid metagenomic assembly resulting in 20 scaffolds totaling 554,025 bp, housing 436 protein-coding genes, 27 tRNA, and 1 rRNA operon. The genome analysis highlighted specific gene distributions, emphasizing translation, ribosomal structure, and biogenesis, with 352 genes assigned to 18 functional categories. Additionally, 322 proteins received functional assignments in the KEGG database, emphasizing 'Genetic Information Processing' and 'Environmental Information Processing'. Key potential pathogenicity factors, including signal peptide proteins and virulence proteins, were identified. Noteworthy findings include homologs of effectors genes like SAP11 and SAP05 and pathogenesis-related proteins, such as hemolysin III and SodA genes, in the SW86 genome. The duplicated cation-transporting P-type ATPase in the SW86 genome suggests a role in enhancing adaptability and contributing to the severity of SSD symptoms. This genome analysis provides crucial insights into the genomic features and potential virulence factors of 'Ca. Phytoplasma asteris' strain SW86, advancing our understanding of pathogenicity mechanisms and offering avenues for future disease management strategies in Indian sandalwood. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-024-03952-5.
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Affiliation(s)
- Kiran Kirdat
- National Centre for Microbial Resource, National Centre for Cell Science, NCCS Complex, Ganeshkhind, Pune, Maharashtra 411007 India
- Department of Microbiology, Tuljaram Chaturchand College, Baramati, Maharashtra 413102 India
| | - Bhavesh Tiwarekar
- National Centre for Microbial Resource, National Centre for Cell Science, NCCS Complex, Ganeshkhind, Pune, Maharashtra 411007 India
| | - K. N. Manjula
- Forest Protection Division, Institute of Wood Science and Technology, 18th Cross, Malleswaram, Bangalore, 560003 India
| | - S. Padma
- Forest Protection Division, Institute of Wood Science and Technology, 18th Cross, Malleswaram, Bangalore, 560003 India
| | - Shivaji Sathe
- Department of Microbiology, Tuljaram Chaturchand College, Baramati, Maharashtra 413102 India
| | - R. Sundararaj
- Forest Protection Division, Institute of Wood Science and Technology, 18th Cross, Malleswaram, Bangalore, 560003 India
| | - Amit Yadav
- National Centre for Microbial Resource, National Centre for Cell Science, NCCS Complex, Ganeshkhind, Pune, Maharashtra 411007 India
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A Varon H, Santos P, Lopez-Vallejo F, Y Soto C. Novel scaffolds targeting Mycobacterium tuberculosis plasma membrane Ca 2+ transporter CtpF by structure-based strategy. Bioorg Chem 2023; 138:106648. [PMID: 37315451 DOI: 10.1016/j.bioorg.2023.106648] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 05/20/2023] [Accepted: 05/30/2023] [Indexed: 06/16/2023]
Abstract
CtpF is a Ca2+ transporter P-type ATPase key to the response to stress conditions and to Mycobacterium tuberculosis virulence, therefore, an interesting target for the design of novel anti-Mtb compounds. In this work, molecular dynamics simulations of four previously identified CtpF inhibitors allowed recognizing the key protein-ligand (P-L) interactions, which were then used to perform a pharmacophore-based virtual screening (PBVS) of 22 million compounds from ZINCPharmer. The top-rated compounds were then subjected to molecular docking, and their scores were refined by MM-GBSA calculations. In vitro assays showed that ZINC04030361 (Compound 7) was the best promising candidate, showing a MIC of 25.0 μg/mL, inhibition of Ca2+-ATPase activity (IC50) of 3.3 μM, cytotoxic activity of 27.2 %, and hemolysis of red blood cells lower than 0.2 %. Interestingly, the ctpF gene is upregulated in the presence of compound 7, compared to other alkali/alkaline P-type ATPases coding genes, strongly suggesting that CtpF is a compound 7-specific target.
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Affiliation(s)
- Henry A Varon
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 N° 45-03, Bogotá, Colombia
| | - Paola Santos
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 N° 45-03, Bogotá, Colombia
| | - Fabian Lopez-Vallejo
- Departamento de Física y Química, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Colombia-Sede Manizales, Kilómetro 9 vía al aeropuerto, La Nubia, Manizales 170003, Colombia.
| | - Carlos Y Soto
- Departamento de Química, Facultad de Ciencias, Universidad Nacional de Colombia, Carrera 30 N° 45-03, Bogotá, Colombia
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Dhankhar P, Trinh TKH, Qiu W, Guo Y. Characterization of Ca 2+-ATPase, LMCA1, with native cell membrane nanoparticles system. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184143. [PMID: 36863681 PMCID: PMC10375462 DOI: 10.1016/j.bbamem.2023.184143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 02/06/2023] [Accepted: 02/16/2023] [Indexed: 03/04/2023]
Abstract
Ca2+-ATPases are membrane pumps that transport calcium ions across the cell membrane and are dependent on ATP. The mechanism of Listeria monocytogenes Ca2+-ATPase (LMCA1) in its native environment remains incompletely understood. LMCA1 has been investigated biochemically and biophysically with detergents in the past. This study characterizes LMCA1 using the detergent-free Native Cell Membrane Nanoparticles (NCMNP) system. As demonstrated by ATPase activity assays, the NCMNP7-25 polymer is compatible with a broad pH range and Ca2+ ions. This result suggests that NCMNP7-25 may have a wider array of applications in membrane protein research.
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Affiliation(s)
- Poonam Dhankhar
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Thi Kim Hoang Trinh
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA
| | - Weihua Qiu
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA.
| | - Youzhong Guo
- Department of Medicinal Chemistry, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23298, USA; Institute for Structural Biology, Drug Discovery, and Development, School of Pharmacy, Virginia Commonwealth University, Richmond, VA 23219, USA.
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The ctpF Gene Encoding a Calcium P-Type ATPase of the Plasma Membrane Contributes to Full Virulence of Mycobacterium tuberculosis. Int J Mol Sci 2022; 23:ijms23116015. [PMID: 35682696 PMCID: PMC9180918 DOI: 10.3390/ijms23116015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/22/2022] [Accepted: 05/24/2022] [Indexed: 12/04/2022] Open
Abstract
Identification of alternative attenuation targets of Mycobacterium tuberculosis (Mtb) is pivotal for designing new candidates for live attenuated anti-tuberculosis (TB) vaccines. In this context, the CtpF P-type ATPase of Mtb is an interesting target; specifically, this plasma membrane enzyme is involved in calcium transporting and response to oxidative stress. We found that a mutant of MtbH37Rv lacking ctpF expression (MtbΔctpF) displayed impaired proliferation in mouse alveolar macrophages (MH-S) during in vitro infection. Further, the levels of tumor necrosis factor and interferon-gamma in MH-S cells infected with MtbΔctpF were similar to those of cells infected with the parental strain, suggesting preservation of the immunogenic capacity. In addition, BALB/c mice infected with Mtb∆ctpF showed median survival times of 84 days, while mice infected with MtbH37Rv survived 59 days, suggesting reduced virulence of the mutant strain. Interestingly, the expression levels of ctpF in a mouse model of latent TB were significantly higher than in a mouse model of progressive TB, indicating that ctpF is involved in Mtb persistence in the dormancy state. Finally, the possibility of complementary mechanisms that counteract deficiencies in Ca2+ transport mediated by P-type ATPases is suggested. Altogether, our results demonstrate that CtpF could be a potential target for Mtb attenuation.
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López-Agudelo VA, Baena A, Barrera V, Cabarcas F, Alzate JF, Beste DJV, Ríos-Estepa R, Barrera LF. Dual RNA Sequencing of Mycobacterium tuberculosis-Infected Human Splenic Macrophages Reveals a Strain-Dependent Host-Pathogen Response to Infection. Int J Mol Sci 2022; 23:ijms23031803. [PMID: 35163725 PMCID: PMC8836425 DOI: 10.3390/ijms23031803] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 12/26/2021] [Accepted: 12/28/2021] [Indexed: 12/13/2022] Open
Abstract
Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb), leading to pulmonary and extrapulmonary TB, whereby Mtb is disseminated to many other organs and tissues. Dissemination occurs early during the disease, and bacteria can be found first in the lymph nodes adjacent to the lungs and then later in the extrapulmonary organs, including the spleen. The early global gene expression response of human tissue macrophages and intracellular clinical isolates of Mtb has been poorly studied. Using dual RNA-seq, we have explored the mRNA profiles of two closely related clinical strains of the Latin American and Mediterranean (LAM) family of Mtb in infected human splenic macrophages (hSMs). This work shows that these pathogens mediate a distinct host response despite their genetic similarity. Using a genome-scale host–pathogen metabolic reconstruction to analyze the data further, we highlight that the infecting Mtb strain also determines the metabolic response of both the host and pathogen. Thus, macrophage ontogeny and the genetic-derived program of Mtb direct the host–pathogen interaction.
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Affiliation(s)
- Víctor A. López-Agudelo
- Grupo de Inmunología Celular e Inmunogenética (GICIG), Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia; (V.A.L.-A.); (A.B.)
- Grupo de Bioprocesos, Facultad de Ingeniería, Universidad de Antioquia, Medellín 050010, Colombia;
| | - Andres Baena
- Grupo de Inmunología Celular e Inmunogenética (GICIG), Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia; (V.A.L.-A.); (A.B.)
| | - Vianey Barrera
- Programa de Ingeniería Biológica, Universidad Nacional de Colombia, Sede Medellín, Medellín 050010, Colombia;
| | - Felipe Cabarcas
- Grupo Sistemas Embebidos e Inteligencia Computacional (SISTEMIC), Facultad de Ingeniería, Universidad de Antioquia, Medellín 050010, Colombia;
| | - Juan F. Alzate
- Centro Nacional de Secuenciación Genómica (CNSG), Sede de Investigación Universitaria (SIU), Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia;
| | - Dany J. V. Beste
- Department of Microbial Sciences, Faculty of Health and Medical Science, University of Surrey, Guildford GU2 7XH, UK;
| | - Rigoberto Ríos-Estepa
- Grupo de Bioprocesos, Facultad de Ingeniería, Universidad de Antioquia, Medellín 050010, Colombia;
| | - Luis F. Barrera
- Grupo de Inmunología Celular e Inmunogenética (GICIG), Instituto de Investigaciones Médicas, Facultad de Medicina, Universidad de Antioquia, Medellín 050010, Colombia; (V.A.L.-A.); (A.B.)
- Correspondence:
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Mathivanan K, Chandirika JU, Vinothkanna A, Yin H, Liu X, Meng D. Bacterial adaptive strategies to cope with metal toxicity in the contaminated environment - A review. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2021; 226:112863. [PMID: 34619478 DOI: 10.1016/j.ecoenv.2021.112863] [Citation(s) in RCA: 56] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/27/2021] [Accepted: 09/30/2021] [Indexed: 06/13/2023]
Abstract
Heavy metal contamination poses a serious environmental hazard, globally necessitating intricate attention. Heavy metals can cause deleterious health hazards to humans and other living organisms even at low concentrations. Environmental biotechnologists and eco-toxicologists have rigorously assessed a plethora of bioremediation mechanisms that can hamper the toxic outcomes and the molecular basis for rejuvenating the hazardous impacts, optimistically. Environmental impact assessment and restoration of native and positive scenario has compelled biological management in ensuring safety replenishment in polluted realms often hindered by heavy metal toxicity. Copious treatment modalities have been corroborated to mitigate the detrimental effects to remove heavy metals from polluted sites. In particular, Biological-based treatment methods are of great attention in the metal removal sector due to their high efficiency at low metal concentrations, ecofriendly nature, and cost-effectiveness. Due to rapid multiplication and growth rates, bacteria having metal resistance are advocated for metal removal applications. Evolutionary implications of coping with heavy metals toxicity have redressed bacterial adaptive/resistance strategies related to physiological and cross-protective mechanisms. Ample reviews have been reported for the bacterial adaptive strategies to cope with heavy metal toxicity. Nevertheless, a holistic review summarizing the redox reactions that address the cross-reactivity mechanisms between metallothionein synthesis, extracellular polysaccharides production, siderophore production, and efflux systems of metal resistant bacteria are scarce. Molecular dissection of how bacteria adapt themselves to metal toxicity can augment novel and innovative technologies for efficient detoxification, removal, and combat the restorative difficulties for stress alleviations. The present comprehensive compilation addresses the identification of newer methodologies, summarizing the prevailing strategies of adaptive/resistance mechanisms in bacterial bioremediation. Further pitfalls and respective future directions are enumerated in invigorating effective bioremediation technologies including overexpression studies and delivery systems. The analysis will aid in abridging the gap for limitations in heavy metal removal strategies and necessary cross-talk in elucidating the complex cascade of events in better bioremediation protocols.
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Affiliation(s)
- Krishnamurthy Mathivanan
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, PR China
| | - Jayaraman Uthaya Chandirika
- Environmental Nanotechnology Division, Sri Paramakalyani Centre for Environmental Sciences, Manonmaniam Sundaranar University, Alwarkurichi, Tamil Nadu 627412, India
| | - Annadurai Vinothkanna
- School of Food and Biological Engineering, Jiangsu University, 301 Xuefu Road, Zhenjiang 212013, PR China
| | - Huaqun Yin
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, PR China; The Hunan International Scientific and Technological Cooperation Base of Environmental Microbiome and Application, Central South University, Changsha 410083, PR China
| | - Xueduan Liu
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, PR China
| | - Delong Meng
- School of Minerals Processing and Bioengineering, Central South University, Changsha 410083, PR China; Key Laboratory of Biometallurgy, Ministry of Education, Central South University, Changsha 410083, PR China; The Hunan International Scientific and Technological Cooperation Base of Environmental Microbiome and Application, Central South University, Changsha 410083, PR China.
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Udhaya Kumar S, Saleem A, Thirumal Kumar D, Anu Preethi V, Younes S, Zayed H, Tayubi IA, George Priya Doss C. A systemic approach to explore the mechanisms of drug resistance and altered signaling cascades in extensively drug-resistant tuberculosis. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2021; 127:343-364. [PMID: 34340773 DOI: 10.1016/bs.apcsb.2021.02.002] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND AND AIM The persistence of extensively drug-resistant (XDR) strains of Mycobacterium tuberculosis (MTB) continue to pose a significant challenge to the treatment and control of tuberculosis infections worldwide. XDR-MTB strains exhibit resistance against first-line anti-TB drugs, fluoroquinolones, and second-line injectable drugs. The mechanisms of drug resistance of MTB remains poorly understood. Our study aims at identifying the differentially expressed genes (DEGs), associated gene networks, and signaling cascades involved in rendering this pathogen resistant to multiple drugs, namely, isoniazid, rifampicin, and capreomycin. METHODS We used the microarray dataset GSE53843. The GEO2R tool was used to prioritize the most significant DEGs (top 250) of each drug exposure sample between XDR strains and non-resistant strains. The validation of the 250 DEGs was performed using volcano plots. Protein-protein interaction networks of the DEGs were created using STRING and Cytoscape tools, which helped decipher the relationship between these genes. The significant DEGs were functionally annotated using DAVID and ClueGO. The concomitant biological processes (BP) and molecular functions (MF) were represented as dot plots. RESULTS AND CONCLUSION We identified relevant molecular pathways and biological processes, such as cell wall biogenesis, lipid metabolic process, ion transport, phosphopantetheine binding, and triglyceride lipase activity. These processes indicated the involvement of multiple interconnected mechanisms in drug resistance. Our study highlighted the impact of cell wall permeability, with the dysregulation of the mur family of proteins, as essential factors in the inference of resistance. Additionally, upregulation of genes responsible for ion transport such as ctpF, arsC, and nark3, emphasizes the importance of transport channels and efflux pumps in potentially driving out stress-inducing compounds. This study investigated the upregulation of the Lip family of proteins, which play a crucial role in triglyceride lipase activity. Thereby illuminating the potential role of drug-induced dormancy and subsequent resistance in the mycobacterial strains. Multiple mechanisms such as carboxylic acid metabolic process, NAD biosynthetic process, triglyceride lipase activity, phosphopantetheine binding, organic acid biosynthetic process, and growth of symbiont in host cell were observed to partake in resistance of XDR-MTB. This study ultimately provides a platform for important mapping targets for potential therapeutics against XDR-MTB.
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Affiliation(s)
- S Udhaya Kumar
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Aisha Saleem
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - D Thirumal Kumar
- Department of Bioinformatics, Saveetha School of Engineering, Saveetha Institute of Medical and Technical Sciences, Chennai, Tamil Nadu, India
| | - V Anu Preethi
- School of Computer Science and Engineering, Vellore Institute of Technology, Vellore, Tamil Nadu, India
| | - Salma Younes
- Translational Research Institute, Women's Wellness and Research Center, Hamad Medical Corporation, Doha, Qatar
| | - Hatem Zayed
- Department of Biomedical Sciences, College of Health and Sciences, QU Health, Qatar University, Doha, Qatar
| | - Iftikhar Aslam Tayubi
- Faculty of Computing and Information Technology, King Abdul-Aziz University, Rabigh, Saudi Arabia
| | - C George Priya Doss
- School of Biosciences and Technology, Vellore Institute of Technology, Vellore, Tamil Nadu, India.
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Identification and in silico functional prediction of lineage-specific SNPs distributed in DosR-related proteins and resuscitation-promoting factor proteins of Mycobacterium tuberculosis. Heliyon 2020; 6:e05744. [PMID: 33364506 PMCID: PMC7753917 DOI: 10.1016/j.heliyon.2020.e05744] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 10/21/2020] [Accepted: 12/11/2020] [Indexed: 11/23/2022] Open
Abstract
One-third of the world population is infected by Mycobacterium tuberculosis, which may persist in the latent or dormant state. Bacteria can shift to dormancy when encountering harsh conditions such as low oxygen, nutrient starvation, high acidity and host immune defenses. Genes related to the dormancy survival regulator (DosR) regulon are responsible for the inhibition of aerobic respiration and replication, which is required to enter dormancy. Conversely, resuscitation-promoting factor (rpf) proteins participate in reactivation from dormancy and the development of active tuberculosis (TB). Many DosR regulon and rpf proteins are immunodominant T cell antigens that are highly expressed in latent TB infection. They could serve as TB vaccine candidates and be used for diagnostic development. We explored the genetic polymorphisms of 50 DosR-related genes and 5 rpf genes among 1,170 previously sequenced clinical M. tuberculosis genomes. Forty-three lineage- or sublineage-specific nonsynonymous single nucleotide polymorphisms (nsSNPs) were identified. Ten nsSNPs were specific to all Mtb isolates belonging to lineage 1 (L1). Two common sublineages, the Beijing family (L2.2) and EAI2 (L1.2.1), differed at as many as 26 lineage- or sublineage-specific SNPs. DosR regulon genes related to membrane proteins and the rpf family possessed mean dN/dS ratios greater than one, suggesting that they are under positive selection. Although the T cell epitope regions of DosR-related and rpf antigens were quite conserved, we found that the epitopes in L1 had higher rates of genetic polymorphisms than the other lineages. Some mutations in immunogenic epitopes of the antigens were specific to particular M. tuberculosis lineages. Therefore, the genetic diversity of the DosR regulon and rpf proteins might impact the adaptation of M. tuberculosis to the dormant state and the immunogenicity of latency antigens, which warrants further investigation.
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Garg R, Borbora SM, Bansia H, Rao S, Singh P, Verma R, Balaji KN, Nagaraja V. Mycobacterium tuberculosis Calcium Pump CtpF Modulates the Autophagosome in an mTOR-Dependent Manner. Front Cell Infect Microbiol 2020; 10:461. [PMID: 33042857 PMCID: PMC7525011 DOI: 10.3389/fcimb.2020.00461] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Accepted: 07/28/2020] [Indexed: 12/17/2022] Open
Abstract
Calcium is a very important second messenger, whose concentration in various cellular compartments is under tight regulation. A disturbance in the levels of calcium in these compartments can play havoc in the cell, as it regulates various cellular processes by direct or indirect mechanisms. Here, we have investigated the functional importance of a calcium transporting P2A ATPase, CtpF of Mycobacterium tuberculosis (Mtb) in the pathogen's interaction with the host. Among its uncanny ways of dealing with the host with umpteen strategies for survival and persistence in humans, CtpF is identified as a new player. The levels of ctpF are upregulated in macrophage stresses like hypoxia, high nitric oxide levels and acidic pH. Using confocal microscopy and fluorimetry, we show that CtpF effluxes calcium in macrophages in early stages of Mtb infection. Downregulation of ctpF expression by conditional knockdown resulted in perturbation of host calcium levels and consequent decreased activation of mTOR. We present a mechanism how calcium efflux by the pathogen inhibits mTOR-dependent autophagy and enhances bacterial survival. Our work highlights how Mtb engages its metal efflux pumps to exploit host autophagic process for its proliferation.
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Affiliation(s)
- Rajni Garg
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
| | - Salik Miskat Borbora
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Harsh Bansia
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Sandhya Rao
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Prakruti Singh
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | - Rinkee Verma
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India
| | | | - Valakunja Nagaraja
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore, India.,Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, India
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