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Sturm A, Sun P, Avila-Pacheco J, Clatworthy AE, Bloom-Ackermann Z, Wuo MG, Gomez JE, Jin S, Clish CB, Kiessling LL, Hung DT. Genetic factors affecting storage and utilization of lipids during dormancy in Mycobacterium tuberculosis. mBio 2024; 15:e0320823. [PMID: 38236034 PMCID: PMC10865790 DOI: 10.1128/mbio.03208-23] [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: 12/05/2023] [Accepted: 12/11/2023] [Indexed: 01/19/2024] Open
Abstract
Mycobacterium tuberculosis (Mtb) can adopt a non-growing dormant state during infection that may be critical to both active and latent tuberculosis. During dormancy, Mtb is widely tolerant toward antibiotics, a significant obstacle in current anti-tubercular drug regimens, and retains the ability to persist in its environment. We aimed to identify novel mechanisms that permit Mtb to survive dormancy in an in vitro carbon starvation model using transposon insertion sequencing and gene expression analysis. We identified a previously uncharacterized component of the lipid transport machinery, omamC, which was upregulated and required for survival during carbon starvation. We show that OmamC plays a role both in increasing fatty acid stores during growth in rich media and enhancing fatty acid utilization during starvation. Besides its involvement in lipid metabolism, OmamC levels affected the expression of the anti-anti-sigma factor rv0516c and other genes to improve Mtb survival during carbon starvation and increase its tolerance toward rifampicin, a first-line drug effective against non-growing Mtb. Importantly, we show that Mtb can be eradicated during carbon starvation, in an OmamC-dependent manner, by inhibiting lipid metabolism with the lipase inhibitor tetrahydrolipstatin. This work casts new light into the survival processes of non-replicating, drug-tolerant Mtb by identifying new proteins involved in lipid metabolism required for the survival of dormant bacteria and exposing a potential vulnerability that could be exploited for antibiotic discovery.IMPORTANCETuberculosis is a global threat, with ~10 million yearly active cases. Many more people, however, live with "latent" infection, where Mycobacterium tuberculosis survives in a non-replicative form. When latent bacteria activate and regrow, they elicit immune responses and result in significant host damage. Replicating and non-growing bacilli can co-exist; however, non-growing bacteria are considerably less sensitive to antibiotics, thus complicating treatment by necessitating long treatment durations. Here, we sought to identify genes important for bacterial survival in this non-growing state using a carbon starvation model. We found that a previously uncharacterized gene, omamC, is involved in storing and utilizing fatty acids as bacteria transition between these two states. Importantly, inhibiting lipid metabolism using a lipase inhibitor eradicates non-growing bacteria. Thus, targeting lipid metabolism may be a viable strategy for treating the non-growing population in strategies to shorten treatment durations of tuberculosis.
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Affiliation(s)
- Alexander Sturm
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Penny Sun
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | | | - Anne E. Clatworthy
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Zohar Bloom-Ackermann
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Michael G. Wuo
- Department of Chemistry, MIT, Cambridge, Massachusetts, USA
| | - James E. Gomez
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
| | - Soomin Jin
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
| | - Clary B. Clish
- Metabolomics Platform, Broad Institute, Cambridge, Massachusetts, USA
| | | | - Deborah T. Hung
- Infectious Disease and Microbiome Program, Broad Institute, Cambridge, Massachusetts, USA
- Department of Molecular Biology and Center for Computational and Integrative Biology, Massachusetts General Hospital, Boston, Massachusetts, USA
- Department of Genetics, Harvard Medical School, Boston, Massachusetts, USA
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Chen Y, Wang Y, Chng SS. A conserved membrane protein negatively regulates Mce1 complexes in mycobacteria. Nat Commun 2023; 14:5897. [PMID: 37736771 PMCID: PMC10517005 DOI: 10.1038/s41467-023-41578-y] [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: 03/04/2023] [Accepted: 09/10/2023] [Indexed: 09/23/2023] Open
Abstract
Tuberculosis continues to pose a serious threat to global health. Mycobacterium tuberculosis, the causative agent of tuberculosis, is an intracellular pathogen that relies on various mechanisms to survive and persist within the host. Among their many virulence factors, mycobacteria encode Mce systems. Some of these systems are implicated in lipid uptake, but the molecular basis for Mce function(s) is poorly understood. To gain insights into the composition and architecture of Mce systems, we characterized the putative Mce1 complex involved in fatty acid transport. We show that the Mce1 system in Mycobacterium smegmatis comprises a canonical ATP-binding cassette transporter associated with distinct heterohexameric assemblies of substrate-binding proteins. Furthermore, we establish that the conserved membrane protein Mce1N negatively regulates Mce1 function via a unique mechanism involving blocking transporter assembly. Our work offers a molecular understanding of Mce complexes, sheds light on mycobacterial lipid metabolism and its regulation, and informs future anti-mycobacterial strategies.
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Affiliation(s)
- Yushu Chen
- Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore
| | - Yuchun Wang
- Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore
| | - Shu-Sin Chng
- Department of Chemistry, National University of Singapore, Singapore, 117543, Singapore.
- Singapore Center for Environmental Life Sciences Engineering, National University of Singapore (SCELSE-NUS), Singapore, 117456, Singapore.
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3
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Chen J, Fruhauf A, Fan C, Ponce J, Ueberheide B, Bhabha G, Ekiert DC. Structure of an endogenous mycobacterial MCE lipid transporter. Nature 2023; 620:445-452. [PMID: 37495693 DOI: 10.1038/s41586-023-06366-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2022] [Accepted: 06/22/2023] [Indexed: 07/28/2023]
Abstract
To replicate inside macrophages and cause tuberculosis, Mycobacterium tuberculosis must scavenge a variety of nutrients from the host1,2. The mammalian cell entry (MCE) proteins are important virulence factors in M. tuberculosis1,3, where they are encoded by large gene clusters and have been implicated in the transport of fatty acids4-7 and cholesterol1,4,8 across the impermeable mycobacterial cell envelope. Very little is known about how cargos are transported across this barrier, and it remains unclear how the approximately ten proteins encoded by a mycobacterial mce gene cluster assemble to transport cargo across the cell envelope. Here we report the cryo-electron microscopy (cryo-EM) structure of the endogenous Mce1 lipid-import machine of Mycobacterium smegmatis-a non-pathogenic relative of M. tuberculosis. The structure reveals how the proteins of the Mce1 system assemble to form an elongated ABC transporter complex that is long enough to span the cell envelope. The Mce1 complex is dominated by a curved, needle-like domain that appears to be unrelated to previously described protein structures, and creates a protected hydrophobic pathway for lipid transport across the periplasm. Our structural data revealed the presence of a subunit of the Mce1 complex, which we identified using a combination of cryo-EM and AlphaFold2, and name LucB. Our data lead to a structural model for Mce1-mediated lipid import across the mycobacterial cell envelope.
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Affiliation(s)
- James Chen
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Alice Fruhauf
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Catherine Fan
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA
| | - Jackeline Ponce
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University School of Medicine, New York, NY, USA
| | - Beatrix Ueberheide
- Proteomics Laboratory, Division of Advanced Research Technologies, New York University School of Medicine, New York, NY, USA
- Department of Biochemistry and Molecular Pharmacology, New York University School of Medicine, New York, NY, USA
- Department of Neurology, New York University School of Medicine, New York, NY, USA
| | - Gira Bhabha
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
| | - Damian C Ekiert
- Department of Cell Biology, New York University School of Medicine, New York, NY, USA.
- Department of Microbiology, New York University School of Medicine, New York, NY, USA.
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Wu Y, Ma J, Shi J, Cao S, Luo J, Zheng T, Wang M. iTRAQ-Based Quantitative Proteomic Analysis of Arthrobacter simplex in Response to Cortisone Acetate and Its Mutants with Improved Δ 1-Dehydrogenation Efficiency. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2023; 71:6376-6388. [PMID: 37043686 DOI: 10.1021/acs.jafc.3c00417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Arthrobacter simplex is extensively used for cortisone acetate (CA) biotransformation in industry, but the Δ1-dehydrogenation molecular fundamental remains unclear. Herein, the comparative proteome revealed several proteins with the potential role in this reaction, which were mainly involved in lipid or amino acid transport and metabolism, energy production and conversion, steroid degradation, and transporter. The influences of six proteins were further confirmed, where pps, MceGA, yrbE4AA, yrbE4BA, and hyp2 showed positive impacts, while hyp1 exhibited a negative effect. Additionally, KsdD5 behaved as the best catalytic enzyme. By the combined manipulation in multiple genes under the control of a stronger promoter, an optimal strain with better catalytic enzyme activity, substrate transportation, and cell stress tolerance was created. After biotechnology optimization, the production peak and productivity were, respectively, boosted by 4.1- and 4.0-fold relative to the initial level. Our work broadens the understanding of the Δ1-dehydrogenation mechanism, also providing effective strategies for excellent steroid-transforming strains.
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Affiliation(s)
- Yan Wu
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Jianan Ma
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Jinghui Shi
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Shuting Cao
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Jianmei Luo
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Tingting Zheng
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
| | - Min Wang
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science and Technology, Tianjin 300457, PR China
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Zhang Y, Zhou X, Yao Y, Xu Q, Shi H, Wang K, Feng W, Shen Y. Coexpression of VHb and MceG genes in Mycobacterium sp. Strain LZ2 enhances androstenone production via immobilized repeated batch fermentation. BIORESOURCE TECHNOLOGY 2021; 342:125965. [PMID: 34563820 DOI: 10.1016/j.biortech.2021.125965] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 09/12/2021] [Accepted: 09/14/2021] [Indexed: 06/13/2023]
Abstract
Androstenone production is limited by low-efficiency substrate transport and dissolved oxygen levels during fermentation. In this study, the coexpression of the optimized Vitreoscilla hemoglobin (VHb) and sterol transporter ATPase (MceG) genes in Mycobacterium sp. LZ2 (Msp) was investigated to alleviate dissolved oxygen and mass transfer limitations. Results revealed that Msp-vgb/mceG effectively improved the growth, production, and adaptation to dissolved oxygen compared with those of Msp. The increased catalase activity and reduced intracellular ROS levels enhanced cell viability and promoted transcription of genes critical for phytosterol metabolism. Bagasse as an immobilization carrier increased the productivity of Msp-vgb/mceG by 56%. Immobilized repeat batch fermentation reduced the biotransformation period from 60 days to 37 days and improved the productivity from 0.039 g/L/h to 0.069 g/L/h. To the best of our knowledge, this work is the first study on the immobilization of recombinant mycobacteria on bagasse for androstenone production.
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Affiliation(s)
- Yang Zhang
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China.
| | - Xiuling Zhou
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Yingying Yao
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Qianqian Xu
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Haiying Shi
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Kuiming Wang
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Wei Feng
- School of Life Science, Liaocheng University, Liaocheng, Shandong 252059, PR China
| | - Yanbing Shen
- Key Laboratory of Industrial Fermentation Microbiology, Ministry of Education, Tianjin Key Laboratory of Industrial Microbiology, College of Biotechnology, Tianjin University of Science & Technology, Tianjin 300457, PR China
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6
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Mycolicibacterium cell factory for the production of steroid-based drug intermediates. Biotechnol Adv 2021; 53:107860. [PMID: 34710554 DOI: 10.1016/j.biotechadv.2021.107860] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 10/19/2021] [Accepted: 10/19/2021] [Indexed: 12/30/2022]
Abstract
Steroid-based drugs have been developed as the second largest medical category in pharmaceutics. The well-established route of steroid industry includes two steps: the conversion of natural products with a steroid framework to steroid-based drug intermediates and the synthesis of varied steroid-based drugs from steroid-based drug intermediates. The biosynthesis of steroid-based drug intermediates from phytosterols by Mycolicibacterium cell factories bypasses the potential undersupply of diosgenin in the traditional steroid chemical industry. Moreover, the biosynthesis route shows advantages on multiple steroid-based drug intermediate products, more ecofriendly processes, and consecutive reactions carried out in one operation step and in one pot. Androsta-4-ene-3,17-dione (AD), androsta-1,4-diene-3,17-dione (ADD) and 9-hydroxyandrostra-4-ene-3,17-dione (9-OH-AD) are the representative steroid-based drug intermediates synthesized by mycolicibacteria. Other steroid metabolites of mycolicibacteria, like 4-androstene-17β-ol-3-one (TS), 22-hydroxy-23,24-bisnorchol-4-ene-3-one (4-HBC), 22-hydroxy-23,24-bisnorchol-1,4-diene-3-one (1,4-HBC), 9,22-dihydroxy-23,24-bisnorchol-4-ene-3-one (9-OH-HBC), 3aα-H-4α-(3'-propionic acid)-7aβ-methylhexahydro-1,5-indanedione (HIP) and 3aα-H-4α-(3'-propionic acid)-5α-hydroxy-7aβ-methylhexahydro-1-indanone-δ-lactone (HIL), also show values as steroid-based drug intermediates. To improve the bio-production efficiency of the steroid-based drug intermediates, mycolicibacterial strains and biotransformation processes have been continuously studied in the past decades. Many mycolicibacteria that accumulate steroid drug intermediates have been isolated, and subsequently optimized by conventional mutagenesis and genetic engineering. Especially, with the clarification of the mycolicibacterial steroid metabolic pathway and the developments on gene editing technologies, rational design is becoming an important measure for the construction and optimization of engineered mycolicibacteria strains that produce steroid-based drug intermediates. Hence, by reviewing researches in the past two decades, this article updates the overall process of steroid metabolism in mycolicibacteria and provides comprehensive schemes for the rational construction of mycolicibacterial strains that accumulate steroid-based drug intermediates. In addition, the special strategies for the bioconversion of highly hydrophobic steroid in aqueous media are discussed as well.
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7
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Evidence for the Mycobacterial Mce4 Transporter Being a Multiprotein Complex. J Bacteriol 2021; 203:JB.00685-20. [PMID: 33649150 DOI: 10.1128/jb.00685-20] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Accepted: 02/24/2021] [Indexed: 01/01/2023] Open
Abstract
Mycobacteria possess Mce transporters that import lipids and are thought to function analogously to ATP-binding cassette (ABC) transporters. However, whereas ABC transporters import substrates using a single solute-binding protein (SBP) to deliver a substrate to permease proteins in the membrane, mycobacterial Mce transporters have a potential for six SBPs (MceA to MceF) working with a pair of permeases (YrbEA and YrbEB), a cytoplasmic ATPase (MceG), and multiple Mce-associated membrane (Mam) and orphaned Mam (Omam) proteins to transport lipids. In this study, we used the model mycobacterium Mycobacterium smegmatis to study the requirement for individual Mce, Mam, and Omam proteins in Mce4 transport of cholesterol. All of the Mce4 and Mam4 proteins we investigated were required for cholesterol uptake. However, not all Omam proteins, which are encoded by genes outside mce loci, proved to contribute to cholesterol import. OmamA and OmamB were required for cholesterol import, while OmamC, OmamD, OmamE, and OmamF were not. In the absence of any single Mce4, Mam4, or Omam protein that we tested, the abundance of Mce4A and Mce4E declined. This relationship between the levels of Mce4A and Mce4E and these additional proteins suggests a network of interactions that assemble and/or stabilize a multiprotein Mce4 transporter complex. Further support for Mce transporters being multiprotein complexes was obtained by immunoprecipitation-mass spectrometry, in which we identified every single Mce, YrbE, MceG, Mam, and Omam protein with a role in cholesterol transport as associating with Mce4A. This study represents the first time any of these Mce4 transporter proteins has been shown to associate.IMPORTANCE How lipids travel between membranes of diderm bacteria is a challenging mechanistic question because lipids, which are hydrophobic molecules, must traverse a hydrophilic periplasm. This question is even more complex for mycobacteria, which have a unique cell envelope that is highly impermeable to molecules. A growing body of knowledge identifies Mce transporters as lipid importers for mycobacteria. Here, using protein stability experiments and immunoprecipitation-mass spectrometry, we provide evidence for mycobacterial Mce transporters existing as multiprotein complexes.
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Cebriá-Mendoza M, Sanjuán R, Domingo-Calap P. Directed Evolution of a Mycobacteriophage. Antibiotics (Basel) 2019; 8:antibiotics8020046. [PMID: 31027152 PMCID: PMC6627502 DOI: 10.3390/antibiotics8020046] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Revised: 04/22/2019] [Accepted: 04/23/2019] [Indexed: 12/03/2022] Open
Abstract
Bacteriophages represent an alternative strategy to combat pathogenic bacteria. Currently, Mycobacterium tuberculosis infections constitute a major public health problem due to extensive antibiotic resistance in some strains. Using a non-pathogenic species of the same genus as an experimental model, Mycobacterium smegmatis, here we have set up a basic methodology for mycobacteriophage growth and we have explored directed evolution as a tool for increasing phage infectivity and lytic activity. We demonstrate mycobacteriophage adaptation to its host under different conditions. Directed evolution could be used for the development of future phage therapy applications against mycobacteria.
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Affiliation(s)
- María Cebriá-Mendoza
- Institute for Integrative Systems Biology (I2SysBio), Universitat de València-CSIC, 46980 Paterna, Valencia, Spain.
| | - Rafael Sanjuán
- Institute for Integrative Systems Biology (I2SysBio), Universitat de València-CSIC, 46980 Paterna, Valencia, Spain.
- Department of Genetics, Universitat de València, 46100 Burjassot, Valencia, Spain.
| | - Pilar Domingo-Calap
- Institute for Integrative Systems Biology (I2SysBio), Universitat de València-CSIC, 46980 Paterna, Valencia, Spain.
- Department of Genetics, Universitat de València, 46100 Burjassot, Valencia, Spain.
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Ogawa N, Kato H, Kishida K, Ichihashi E, Ishige T, Yoshikawa H, Nagata Y, Ohtsubo Y, Tsuda M. Suppression of substrate inhibition in phenanthrene-degrading Mycobacterium by co-cultivation with a non-degrading Burkholderia strain. MICROBIOLOGY-SGM 2019; 165:625-637. [PMID: 30994434 DOI: 10.1099/mic.0.000801] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In natural environments contaminated by recalcitrant organic pollutants, efficient biodegradation of such pollutants has been suggested to occur through the cooperation of different bacterial species. A phenanthrene-degrading bacterial consortium, MixEPa4, from polluted soil was previously shown to include a phenanthrene-degrading strain, Mycobacterium sp. EPa45, and a non-polycyclic aromatic hydrocarbon (PAH)-degrading strain, Burkholderia sp. Bcrs1W. In this study, we show that addition of phenanthrene to rich liquid medium resulted in the transient growth arrest of EPa45 during its degradation of phenanthrene. RNA-sequencing analysis of the growth-arrested cells showed the phenanthrene-dependent induction of genes that were predicted to be involved in the catabolism of this compound, and many other cell systems, such as a ferric iron-uptake, were up-regulated, implying iron deficiency of the cells. This negative effect of phenanthrene became much more apparent when using phenanthrene-containing minimal agar medium; colony formation of EPa45 on such agar was significantly inhibited in the presence of phenanthrene and its intermediate degradation products. However, growth inhibition was suppressed by the co-residence of viable Bcrs1W cells. Various Gram-negative bacterial strains, including the three other strains from MixEPa4, also exhibited varying degrees of suppression of the growth inhibition effect on EPa45, strongly suggesting that this effect is not strain-specific. Growth inhibition of EPa45 was also observed by other PAHs, biphenyl and naphthalene, and these two compounds and phenanthrene also inhibited the growth of another mycobacterial strain, M. vanbaalenii PYR-1, that can use them as carbon sources. These phenomena of growth inhibition were also suppressed by Bcrs1W. Our findings suggest that, in natural environments, various non-PAH-degrading bacterial strains play potentially important roles in the facilitation of PAH degradation by the co-residing mycobacteria.
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Affiliation(s)
- Natsumi Ogawa
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Hiromi Kato
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Kouhei Kishida
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Eikichi Ichihashi
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Taichiro Ishige
- 2 Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Tokyo 156-8502, Japan
| | - Hirofumi Yoshikawa
- 2 Tokyo University of Agriculture, 1-1-1 Sakuragaoka, Tokyo 156-8502, Japan
| | - Yuji Nagata
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Yoshiyuki Ohtsubo
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
| | - Masataka Tsuda
- 1 Graduate School of Life Sciences, Tohoku University, 2-1-1 Katahira, Sendai 980-8577, Japan
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10
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Nazarova EV, Montague CR, Huang L, La T, Russell D, VanderVen BC. The genetic requirements of fatty acid import by Mycobacterium tuberculosis within macrophages. eLife 2019; 8:e43621. [PMID: 30735132 PMCID: PMC6368401 DOI: 10.7554/elife.43621] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Accepted: 01/10/2019] [Indexed: 12/11/2022] Open
Abstract
Mycobacterium tuberculosis (Mtb) imports and metabolizes fatty acids to maintain infection within human macrophages. Although this is a well-established paradigm, the bacterial factors required for fatty acid import are poorly understood. Previously, we found that LucA and Mce1 are required for fatty acid import in Mtb (Nazarova et al., 2017). Here, we identified additional Mtb mutants that have a reduced ability to import a fluorescent fatty acid substrate during infection within macrophages. This screen identified the novel genes as rv2799 and rv0966c as be necessary for fatty acid import and confirmed the central role for Rv3723/LucA and putative components of the Mce1 fatty acid transporter (Rv0200/OmamB, Rv0172/Mce1D, and Rv0655/MceG) in this process.
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Affiliation(s)
- Evgeniya V Nazarova
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Christine R Montague
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Lu Huang
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Thuy La
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - David Russell
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
| | - Brian C VanderVen
- Department of Microbiology and Immunology, College of Veterinary MedicineCornell UniversityIthacaUnited States
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11
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Soran H, Ho JH, Durrington PN. Acquired low cholesterol: diagnosis and relevance to safety of low LDL therapeutic targets. Curr Opin Lipidol 2018; 29:318-326. [PMID: 29746303 DOI: 10.1097/mol.0000000000000526] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
PURPOSE OF REVIEW Acquired hypocholesterolaemia occurs more commonly than inherited hypocholesterolaemia but has received little attention in the literature. In this review, we discuss the causes and underlying mechanisms of acquired hypocholesterolaemia and its relevance to safety of therapeutically induced decreased LDL cholesterol levels. RECENT FINDINGS Hypocholesterolaemia is increasingly identified as cholesterol testing becomes more widespread in the assessment of cardiovascular risk. Lower therapeutic targets for LDL cholesterol are also being achieved more regularly with the introduction of more intensive cholesterol-lowering regimens. Acquired hypocholesterolaemia may be the presenting feature of treatable diseases. Understanding its mechanisms may also provide new treatment approaches for neoplastic disease, such as breast cancer, and infections, such as tuberculosis. SUMMARY When hypocholesterolaemia is discovered, it is important to identify its cause. Further research into the pathogenesis of hypocholesterolaemia may provide new therapies for primary diseases underlying it.
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Affiliation(s)
- Handrean Soran
- Lipoprotein Research Group, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester
- Department of Medicine, Manchester University NHS Foundation Trust, Manchester, UK
| | - Jan Hoong Ho
- Lipoprotein Research Group, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester
- Department of Medicine, Manchester University NHS Foundation Trust, Manchester, UK
| | - Paul N Durrington
- Lipoprotein Research Group, Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester
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Martin A, Daniel J. The ABC transporter Rv1272c of Mycobacterium tuberculosis enhances the import of long-chain fatty acids in Escherichia coli. Biochem Biophys Res Commun 2018; 496:667-672. [DOI: 10.1016/j.bbrc.2018.01.115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 01/17/2018] [Indexed: 10/18/2022]
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García-Fernández J, Papavinasasundaram K, Galán B, Sassetti CM, García JL. Molecular and functional analysis of the mce4 operon in Mycobacterium smegmatis. Environ Microbiol 2017; 19:3689-3699. [PMID: 28752922 DOI: 10.1111/1462-2920.13869] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2017] [Revised: 07/11/2017] [Accepted: 07/24/2017] [Indexed: 11/30/2022]
Abstract
Mycobacterium smegmatis contains 6 homologous mce (mammalian cell entry) operons which have been proposed to encode ABC-like import systems. The mce operons encode up to 10 different proteins of unknown function that are not present in conventional ABC transporters. We have analysed the consequences of individually deleting each of the genes of the mce4 operon of M. smegmatis, which mediates the transport of cholesterol. None of the mce4 mutants were able to grow in cholesterol suggesting that all these genes are required for its uptake and that none of them can be replaced by the homologous genes of the other mce operons. This result suggests that different mce operons do not provide redundant capabilities and that M. smegmatis, in contrast with Mycobacterium tuberculosis, is not able to use alternative systems to import cholesterol in the analysed culture conditions. Either deletion of the entire mce4 operon or single point mutations that eliminate the transport function cause a phenotype similar to the one observed in a mutant lacking all 6 mce operons suggesting a pleiotropic role for this system.
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Affiliation(s)
- Julia García-Fernández
- Department of Environmental Biology, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain
| | - Kadamba Papavinasasundaram
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - Beatriz Galán
- Department of Environmental Biology, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain
| | - Christopher M Sassetti
- Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, MA, USA
| | - José L García
- Department of Environmental Biology, Centro de Investigaciones Biológicas (CIB-CSIC), Madrid, Spain
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Nazarova EV, Montague CR, La T, Wilburn KM, Sukumar N, Lee W, Caldwell S, Russell DG, VanderVen BC. Rv3723/LucA coordinates fatty acid and cholesterol uptake in Mycobacterium tuberculosis. eLife 2017; 6:e26969. [PMID: 28708968 PMCID: PMC5487216 DOI: 10.7554/elife.26969] [Citation(s) in RCA: 106] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2017] [Accepted: 06/07/2017] [Indexed: 01/05/2023] Open
Abstract
Pathogenic bacteria have evolved highly specialized systems to extract essential nutrients from their hosts. Mycobacterium tuberculosis (Mtb) scavenges lipids (cholesterol and fatty acids) to maintain infections in mammals but mechanisms and proteins responsible for the import of fatty acids in Mtb were previously unknown. Here, we identify and determine that the previously uncharacterized protein Rv3723/LucA, functions to integrate cholesterol and fatty acid uptake in Mtb. Rv3723/LucA interacts with subunits of the Mce1 and Mce4 complexes to coordinate the activities of these nutrient transporters by maintaining their stability. We also demonstrate that Mce1 functions as a fatty acid transporter in Mtb and determine that facilitating cholesterol and fatty acid import via Rv3723/LucA is required for full bacterial virulence in vivo. These data establish that fatty acid and cholesterol assimilation are inexorably linked in Mtb and reveals a key function for Rv3723/LucA in in coordinating thetransport of both these substrates.
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Affiliation(s)
- Evgeniya V Nazarova
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Christine R Montague
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Thuy La
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Kaley M Wilburn
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Neelima Sukumar
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Wonsik Lee
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Shannon Caldwell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - David G Russell
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
| | - Brian C VanderVen
- Department of Microbiology and Immunology, College of Veterinary Medicine, Cornell University, Ithaca, United States
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