1
|
Haller YA, Jiang J, Wan Z, Childress A, Wang S, Haydel SE. M. tuberculosis PrrA binds the dosR promoter and regulates mycobacterial adaptation to hypoxia. Tuberculosis (Edinb) 2024; 148:102531. [PMID: 38885567 DOI: 10.1016/j.tube.2024.102531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2024] [Revised: 05/30/2024] [Accepted: 06/05/2024] [Indexed: 06/20/2024]
Abstract
The PrrAB two-component system (TCS) is essential for Mycobacterium tuberculosis viability. Previously, it was demonstrated that PrrA binds DNA in the absence of PrrB-mediated transphosphorylation and that non-cognate serine/threonine-kinases phosphorylate PrrA threonine-6 (T6). Therefore, we investigated the differential binding affinity and regulatory properties of the M. tuberculosis-derived wild-type PrrA, PrrA phosphomimetic (D58E, T6E), and PrrA phosphoablative (D58A, T6A) proteins with the prrAMtb, dosRMtb, and cydAMtb genes. While we hypothesized greater DNA binding affinity and more pronounced regulation by PrrA phosphomimetic variants, recombinant, wild-type PrrAMtb bound DNA with greatest affinity. Collectively, wild-type PrrAMtb recombinant protein displayed the highest binding affinity to the dosRMtb promoter (KD 3.46 ± 2.09 nM), followed by the prrAMtb promoter (KD 9.00 ± 2.66 nM). To establish PrrAMtb regulatory activity, we constructed M. smegmatis ΔprrABMsmeg::prrAMtb strains with each of the PrrAMtb variants and extrachromosomal prrAMtb, dosRMtb, and cydAMtb promoter-mCherry reporter fusions. Our findings showed that PrrAMtb is autoregulatory and induces dosRMtb expression only during in vitro, hypoxic growth. Combined expression of prrABMtb in M. smegmatis ΔprrAB significantly induced cydAMtb promoter-mCherry expression. Our studies advanced the understanding of PrrA function and PrrAB phosphorylation-mediated regulatory mechanisms and control of mycobacterial dosR and cydA hypoxic and low-oxygen responsive genes.
Collapse
Affiliation(s)
- Yannik A Haller
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA
| | - Jiapei Jiang
- Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA; School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Zijian Wan
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA; School of Electrical, Computer and Energy Engineering, Arizona State University, Tempe, AZ, USA
| | - Alexia Childress
- School of Life Sciences, Arizona State University, Tempe, AZ, USA
| | - Shaopeng Wang
- Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA; School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ, USA
| | - Shelley E Haydel
- School of Life Sciences, Arizona State University, Tempe, AZ, USA; Biodesign Institute Center for Bioelectronics and Biosensors, Arizona State University, Tempe, AZ, USA.
| |
Collapse
|
2
|
Flores-Valdez MA, Peterson EJR, Aceves-Sánchez MDJ, Baliga NS, Morita YS, Sparks IL, Saini DK, Yadav R, Lang R, Mata-Espinosa D, León-Contreras JC, Hernández-Pando R. Comparison of the transcriptome, lipidome, and c-di-GMP production between BCGΔBCG1419c and BCG, with Mincle- and Myd88-dependent induction of proinflammatory cytokines in murine macrophages. Sci Rep 2024; 14:11898. [PMID: 38789479 PMCID: PMC11126594 DOI: 10.1038/s41598-024-61815-8] [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: 02/06/2024] [Accepted: 05/09/2024] [Indexed: 05/26/2024] Open
Abstract
We have previously reported the transcriptomic and lipidomic profile of the first-generation, hygromycin-resistant (HygR) version of the BCGΔBCG1419c vaccine candidate, under biofilm conditions. We recently constructed and characterized the efficacy, safety, whole genome sequence, and proteomic profile of a second-generation version of BCGΔBCG1419c, a strain lacking the BCG1419c gene and devoid of antibiotic markers. Here, we compared the antibiotic-less BCGΔBCG1419c with BCG. We assessed their colonial and ultrastructural morphology, biofilm, c-di-GMP production in vitro, as well as their transcriptomic and lipidomic profiles, including their capacity to activate macrophages via Mincle and Myd88. Our results show that BCGΔBCG1419c colonial and ultrastructural morphology, c-di-GMP, and biofilm production differed from parental BCG, whereas we found no significant changes in its lipidomic profile either in biofilm or planktonic growth conditions. Transcriptomic profiling suggests changes in BCGΔBCG1419c cell wall and showed reduced transcription of some members of the DosR, MtrA, and ArgR regulons. Finally, induction of TNF-α, IL-6 or G-CSF by bone-marrow derived macrophages infected with either BCGΔBCG1419c or BCG required Mincle and Myd88. Our results confirm that some differences already found to occur in HygR BCGΔBCG1419c compared with BCG are maintained in the antibiotic-less version of this vaccine candidate except changes in production of PDIM. Comparison with previous characterizations conducted by OMICs show that some differences observed in BCGΔBCG1419c compared with BCG are maintained whereas others are dependent on the growth condition employed to culture them.
Collapse
Affiliation(s)
- Mario Alberto Flores-Valdez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C., Av. Normalistas 800, Col. Colinas de la Normal, 44270, Guadalajara, Jalisco, Mexico.
| | | | - Michel de Jesús Aceves-Sánchez
- Biotecnología Médica y Farmacéutica, Centro de Investigación y Asistencia en Tecnología y Diseño del Estado de Jalisco, A.C., Av. Normalistas 800, Col. Colinas de la Normal, 44270, Guadalajara, Jalisco, Mexico
| | | | - Yasu S Morita
- Department of Microbiology, University of Massachusetts, 639 N Pleasant St, Amherst, MA, 01003, USA
| | - Ian L Sparks
- Department of Microbiology, University of Massachusetts, 639 N Pleasant St, Amherst, MA, 01003, USA
| | - Deepak Kumar Saini
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Rahul Yadav
- Department of Developmental Biology and Genetics, Indian Institute of Science, Bangalore, 560012, India
| | - Roland Lang
- Institut für Klinische Mikrobiologie, Immunologie und Hygiene, Universitätsklinikum Erlangen, Erlangen, Germany
| | - Dulce Mata-Espinosa
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez Sección 16, Tlalpan, Mexico City, Mexico
| | - Juan Carlos León-Contreras
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez Sección 16, Tlalpan, Mexico City, Mexico
| | - Rogelio Hernández-Pando
- Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Vasco de Quiroga 15, Belisario Domínguez Sección 16, Tlalpan, Mexico City, Mexico
| |
Collapse
|
3
|
Frando A, Grundner C. More than two components: complexities in bacterial phosphosignaling. mSystems 2024; 9:e0028924. [PMID: 38591891 PMCID: PMC11097640 DOI: 10.1128/msystems.00289-24] [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] [Indexed: 04/10/2024] Open
Abstract
For over 40 years, the two-component systems (TCSs) have taken front and center in our thinking about the signaling mechanisms by which bacteria sense and respond to their environment. In contrast, phosphorylation on Ser/Thr and Tyr (O-phosphorylation) was long thought to be mostly restricted to eukaryotes and a somewhat accessory signaling mechanism in bacteria. Several recent studies exploring systems aspects of bacterial O-phosphorylation, however, now show that it is in fact pervasive, with some bacterial proteomes as highly phosphorylated as those of eukaryotes. Labile, non-canonical protein phosphorylation sites on Asp, Arg, and His are now also being identified in large numbers in bacteria and first cellular functions are discovered. Other phosphomodifications on Cys, Glu, and Lys remain largely unexplored. The surprising breadth and complexity of bacterial phosphosignaling reveals a vast signaling capacity, the full scope of which we may only now be beginning to understand but whose functions are likely to affect all aspects of bacterial physiology and pathogenesis.
Collapse
Affiliation(s)
- Andrew Frando
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
| | - Christoph Grundner
- Center for Global Infectious Disease Research, Seattle Children’s Research Institute, Seattle, Washington, USA
- Department of Pediatrics, University of Washington, Seattle, Washington, USA
- Department of Global Health, University of Washington, Seattle, Washington, USA
| |
Collapse
|
4
|
Dechow SJ, Abramovitch RB. Targeting Mycobacterium tuberculosis pH-driven adaptation. MICROBIOLOGY (READING, ENGLAND) 2024; 170:001458. [PMID: 38717801 PMCID: PMC11165653 DOI: 10.1099/mic.0.001458] [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: 12/15/2023] [Accepted: 04/17/2024] [Indexed: 06/13/2024]
Abstract
Mycobacterium tuberculosis (Mtb) senses and adapts to host environmental cues as part of its pathogenesis. One important cue sensed by Mtb is the acidic pH of its host niche - the macrophage. Acidic pH induces widespread transcriptional and metabolic remodelling in Mtb. These adaptations to acidic pH can lead Mtb to slow its growth and promote pathogenesis and antibiotic tolerance. Mutants defective in pH-dependent adaptations exhibit reduced virulence in macrophages and animal infection models, suggesting that chemically targeting these pH-dependent pathways may have therapeutic potential. In this review, we discuss mechanisms by which Mtb regulates its growth and metabolism at acidic pH. Additionally, we consider the therapeutic potential of disrupting pH-driven adaptations in Mtb and review the growing class of compounds that exhibit pH-dependent activity or target pathways important for adaptation to acidic pH.
Collapse
Affiliation(s)
- Shelby J. Dechow
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, MI 48824, USA
| | - Robert B. Abramovitch
- Department of Microbiology, Genetics and Immunology, Michigan State University, East Lansing, MI 48824, USA
| |
Collapse
|
5
|
Frando A, Boradia V, Grundner C. Regulatory Intersection of Two-component System and Ser/Thr Protein Kinase Signaling in Mycobacterium tuberculosis. J Mol Biol 2024; 436:168379. [PMID: 38043732 PMCID: PMC11251531 DOI: 10.1016/j.jmb.2023.168379] [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: 08/28/2023] [Revised: 11/27/2023] [Accepted: 11/28/2023] [Indexed: 12/05/2023]
Abstract
Phosphosignaling in bacteria is mediated by two distinct systems, the two-component systems (TCSs) and the protein Ser/Thr/Tyr, or O-phosphorylation systems. These two arms of phosphosignaling are currently thought to be largely independent from one another. We mined a deep Mycobacterium tuberculosis (Mtb) phosphoproteome and identified over 170 O-phosphorylation sites on histidine kinases and response regulators of TCSs, suggesting that the two signaling pathways extensively intersect. Several TCSs were phosphorylated on multiple sites, and many by multiple Ser/Thr protein kinases, suggesting convergent and cooperative regulatory interactions. To test in which way these O-phosphorylation sites affect TCS activity, we reconstituted the NarSL phosphorelay in vitro. The Ser/Thr protein kinase PknL phosphorylated the histidine kinase NarS and activated its autophosphorylating activity. A phosphoablative mutation at the PknL phosphorylation site Thr380 resulted in low autophosphorylating activity, whereas a phosphomimetic mutation strongly activated autophosphorylation. The phosphomimetic mutation also resulted in more efficient phosphotransfer from NarS to the response regulator NarL and suppression of gene expression. These data show control of NarSL signaling by STPKs through a phosphoswitch and point to extensive, functional crosstalk between TCSs and O-phosphorylation.
Collapse
Affiliation(s)
- Andrew Frando
- Seattle Children's Research Institute, Seattle, WA, United States
| | - Vishant Boradia
- Seattle Children's Research Institute, Seattle, WA, United States
| | - Christoph Grundner
- Seattle Children's Research Institute, Seattle, WA, United States; Department of Pediatrics, University of Washington, Seattle, WA, United States; Department of Global Health, United States.
| |
Collapse
|
6
|
Chen Y, MacGilvary NJ, Tan S. Mycobacterium tuberculosis response to cholesterol is integrated with environmental pH and potassium levels via a lipid metabolism regulator. PLoS Genet 2024; 20:e1011143. [PMID: 38266039 PMCID: PMC10843139 DOI: 10.1371/journal.pgen.1011143] [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: 11/09/2023] [Revised: 02/05/2024] [Accepted: 01/19/2024] [Indexed: 01/26/2024] Open
Abstract
Successful colonization of the host requires Mycobacterium tuberculosis (Mtb) to sense and respond coordinately to disparate environmental cues during infection and adapt its physiology. However, how Mtb response to environmental cues and the availability of key carbon sources may be integrated is poorly understood. Here, by exploiting a reporter-based genetic screen, we have unexpectedly found that overexpression of transcription factors involved in Mtb lipid metabolism altered the dampening effect of low environmental potassium concentrations ([K+]) on the pH response of Mtb. Cholesterol is a major carbon source for Mtb during infection, and transcriptional analyses revealed that Mtb response to acidic pH was augmented in the presence of cholesterol and vice versa. Strikingly, deletion of the putative lipid regulator mce3R had little effect on Mtb transcriptional response to acidic pH or cholesterol individually, but resulted specifically in loss of cholesterol response augmentation in the simultaneous presence of acidic pH. Similarly, while mce3R deletion had little effect on Mtb response to low environmental [K+] alone, augmentation of the low [K+] response by the simultaneous presence of cholesterol was lost in the mutant. Finally, a mce3R deletion mutant was attenuated for growth in foamy macrophages and for colonization in a murine infection model that recapitulates caseous necrotic lesions and the presence of foamy macrophages. These findings reveal the critical coordination between Mtb response to environmental cues and cholesterol, a vital carbon source, and establishes Mce3R as a transcription factor that crucially serves to integrate these signals.
Collapse
Affiliation(s)
- Yue Chen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| | - Nathan J. MacGilvary
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
- Current affiliation: Department of Molecular, Cell, and Cancer Biology, University of Massachusetts Chan Medical School, Worcester, Massachusetts, United States of America
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, United States of America
| |
Collapse
|
7
|
Belardinelli JM, Arora D, Avanzi C, Wheat WH, Bryant JM, Spencer JS, Blundell TL, Parkhill J, Floto RA, Jackson M. Clinically relevant mutations in the PhoR sensor kinase of host-adapted Mycobacterium abscessus isolates impact response to acidic pH and virulence. Microbiol Spectr 2023; 11:e0158823. [PMID: 37874174 PMCID: PMC10715180 DOI: 10.1128/spectrum.01588-23] [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: 04/17/2023] [Accepted: 09/14/2023] [Indexed: 10/25/2023] Open
Abstract
IMPORTANCE Difficult-to-treat pulmonary infections caused by nontuberculous mycobacteria of the Mycobacterium abscessus group have been steadily increasing in the USA and globally. Owing to the relatively recent recognition of M. abscessus as a human pathogen, basic and translational research to address critical gaps in diagnosis, treatment, and prevention of diseases caused by this microorganism has been lagging behind that of the better-known mycobacterial pathogen, Mycobacterium tuberculosis. To begin unraveling the molecular mechanisms of pathogenicity of M. abscessus, we here focus on the study of a two-component regulator known as PhoPR which we found to be under strong evolutionary pressure during human lung infection. We show that PhoPR is activated at acidic pH and serves to regulate a defined set of genes involved in host adaptation. Accordingly, clinical isolates from chronically infected human lungs tend to hyperactivate this regulator enabling M. abscessus to escape macrophage killing.
Collapse
Affiliation(s)
- Juan M Belardinelli
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University , Fort Collins, Colorado, USA
| | - Divya Arora
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology , Cambridge, United Kingdom
| | - Charlotte Avanzi
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University , Fort Collins, Colorado, USA
| | - William H Wheat
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University , Fort Collins, Colorado, USA
| | - Josephine M Bryant
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology , Cambridge, United Kingdom
- University of Cambridge Centre for AI in Medicine , Cambridge, United Kingdom
| | - John S Spencer
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University , Fort Collins, Colorado, USA
| | - Tom L Blundell
- Department of Biochemistry, University of Cambridge , Cambridge, United Kingdom
| | - Julian Parkhill
- Wellcome Sanger Institute , Hinxton, United Kingdom
- Department of Veterinary Medicine, University of Cambridge , Cambridge, United Kingdom
| | - R Andres Floto
- Department of Medicine, Molecular Immunity Unit, University of Cambridge, MRC-Laboratory of Molecular Biology , Cambridge, United Kingdom
- University of Cambridge Centre for AI in Medicine , Cambridge, United Kingdom
- Cambridge Centre for Lung Infection, Papworth Hospital , Cambridge, United Kingdom
| | - Mary Jackson
- Department of Microbiology, Immunology and Pathology, Mycobacteria Research Laboratories, Colorado State University , Fort Collins, Colorado, USA
| |
Collapse
|
8
|
Singh PR, Goar H, Paul P, Mehta K, Bamniya B, Vijjamarri AK, Bansal R, Khan H, Karthikeyan S, Sarkar D. Dual functioning by the PhoR sensor is a key determinant to Mycobacterium tuberculosis virulence. PLoS Genet 2023; 19:e1011070. [PMID: 38100394 PMCID: PMC10723718 DOI: 10.1371/journal.pgen.1011070] [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: 06/14/2023] [Accepted: 11/16/2023] [Indexed: 12/17/2023] Open
Abstract
PhoP-PhoR, one of the 12 two-component systems (TCSs) that empower M. tuberculosis to sense and adapt to diverse environmental conditions, remains essential for virulence, and therefore, represents a major target to develop novel anti-TB therapies. Although both PhoP and PhoR have been structurally characterized, the signal(s) that this TCS responds to remains unknown. Here, we show that PhoR is a sensor of acidic pH/high salt conditions, which subsequently activate PhoP via phosphorylation. In keeping with this, transcriptomic data uncover that acidic pH- inducible expression of PhoP regulon is significantly inhibited in a PhoR-deleted M. tuberculosis. Strikingly, a set of PhoP regulon genes displayed a low pH-dependent activation even in the absence of PhoR, suggesting the presence of non-canonical mechanism(s) of PhoP activation. Using genome-wide interaction-based screening coupled with phosphorylation assays, we identify a non-canonical mechanism of PhoP phosphorylation by the sensor kinase PrrB. To investigate how level of P~PhoP is regulated, we discovered that in addition to its kinase activity PhoR functions as a phosphatase of P~PhoP. Our subsequent results identify the motif/residues responsible for kinase/phosphatase dual functioning of PhoR. Collectively, these results uncover that contrasting kinase and phosphatase functions of PhoR determine the homeostatic mechanism of regulation of intra-mycobacterial P~PhoP which controls the final output of the PhoP regulon. Together, these results connect PhoR to pH-dependent activation of PhoP with downstream functioning of the regulator. Thus, PhoR plays a central role in mycobacterial adaptation to low pH conditions within the host macrophage phagosome, and a PhoR-deleted M. tuberculosis remains significantly attenuated in macrophages and animal models.
Collapse
Affiliation(s)
| | - Harsh Goar
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
| | - Partha Paul
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
| | - Khushboo Mehta
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Bhanwar Bamniya
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | | | - Roohi Bansal
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
| | - Hina Khan
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
| | - Subramanian Karthikeyan
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| | - Dibyendu Sarkar
- CSIR-Institute of Microbial Technology, Sector 39 A, Chandigarh, India
- Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, India
| |
Collapse
|
9
|
Chen Y, MacGilvary NJ, Tan S. Mycobacterium tuberculosis response to cholesterol is integrated with environmental pH and potassium levels via a lipid utilization regulator. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.22.554309. [PMID: 37662244 PMCID: PMC10473576 DOI: 10.1101/2023.08.22.554309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
How bacterial response to environmental cues and nutritional sources may be integrated in enabling host colonization is poorly understood. Exploiting a reporter-based screen, we discovered that overexpression of Mycobacterium tuberculosis (Mtb) lipid utilization regulators altered Mtb acidic pH response dampening by low environmental potassium (K+). Transcriptional analyses unveiled amplification of Mtb response to acidic pH in the presence of cholesterol, a major carbon source for Mtb during infection, and vice versa. Strikingly, deletion of the putative lipid regulator mce3R resulted in loss of augmentation of (i) cholesterol response at acidic pH, and (ii) low [K+] response by cholesterol, with minimal effect on Mtb response to each signal individually. Finally, the ∆mce3R mutant was attenuated for colonization in a murine model that recapitulates lesions with lipid-rich foamy macrophages. These findings reveal critical coordination between bacterial response to environmental and nutritional cues, and establish Mce3R as a crucial integrator of this process.
Collapse
Affiliation(s)
- Yue Chen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Nathan J. MacGilvary
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
| |
Collapse
|
10
|
Chen Y, Quirk NF, Tan S. Shining a light on bacterial environmental cue integration and its relation to metabolism. Mol Microbiol 2023; 120:71-74. [PMID: 37433048 PMCID: PMC10348474 DOI: 10.1111/mmi.15065] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2023] [Revised: 04/05/2023] [Accepted: 04/06/2023] [Indexed: 07/13/2023]
Abstract
The ability of a bacterium to successfully colonize its host is dependent on proper adaptation to its local environment. Environmental cues are diverse in nature, ranging from ions to bacterial-produced signals, and to host immune responses that can also be exploited by the bacteria as cues. Simultaneously, bacterial metabolism must be matched to the carbon and nitrogen sources available at a given time and location. While initial characterization of a bacterium's response to a given environmental cue or its ability to utilize a particular carbon/nitrogen source requires study of the signal in question in isolation, actual infection poses a situation where multiple signals are present concurrently. This perspective focuses on the untapped potential in uncovering and understanding how bacteria integrate their response to multiple concurrent environmental cues, and in elucidating the possible intrinsic coordination of bacterial environmental response with its metabolism.
Collapse
Affiliation(s)
- Yue Chen
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
| | - Natalia F. Quirk
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
| | - Shumin Tan
- Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, Massachusetts, USA
- Graduate Program in Molecular Microbiology, Graduate School of Biomedical Sciences, Tufts University, Boston, Massachusetts, USA
| |
Collapse
|