1
|
Dai S, Wang B, Ye R, Zhang D, Xie Z, Yu N, Cai C, Huang C, Zhao J, Zhang F, Hua Y, Zhao Y, Zhou R, Tian B. Structural Evolution of Bacterial Polyphosphate Degradation Enzyme for Phosphorus Cycling. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2024; 11:e2309602. [PMID: 38682481 PMCID: PMC11234463 DOI: 10.1002/advs.202309602] [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: 12/09/2023] [Revised: 03/22/2024] [Indexed: 05/01/2024]
Abstract
Living organisms ranging from bacteria to animals have developed their own ways to accumulate and store phosphate during evolution, in particular as the polyphosphate (polyP) granules in bacteria. Degradation of polyP into phosphate is involved in phosphorus cycling, and exopolyphosphatase (PPX) is the key enzyme for polyP degradation in bacteria. Thus, understanding the structure basis of PPX is crucial to reveal the polyP degradation mechanism. Here, it is found that PPX structure varies in the length of ɑ-helical interdomain linker (ɑ-linker) across various bacteria, which is negatively correlated with their enzymatic activity and thermostability - those with shorter ɑ-linkers demonstrate higher polyP degradation ability. Moreover, the artificial DrPPX mutants with shorter ɑ-linker tend to have more compact pockets for polyP binding and stronger subunit interactions, as well as higher enzymatic efficiency (kcat/Km) than that of DrPPX wild type. In Deinococcus-Thermus, the PPXs from thermophilic species possess a shorter ɑ-linker and retain their catalytic ability at high temperatures (70 °C), which may facilitate the thermophilic species to utilize polyP in high-temperature environments. These findings provide insights into the interdomain linker length-dependent evolution of PPXs, which shed light on enzymatic adaption for phosphorus cycling during natural evolution and rational design of enzyme.
Collapse
Affiliation(s)
- Shang Dai
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- Shanghai Institute for Advanced Study of Zhejiang UniversityShanghai201203China
| | - Binqiang Wang
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- State Key Laboratory of Clean Energy UtilizationZhejiang UniversityHangzhou310029China
- Zhejiang Baima Lake Laboratory Co., LtdHangzhou310029China
| | - Rui Ye
- School of PhysicsInstitute of Quantitative BiologyZhejiang UniversityHangzhou310029China
| | - Dong Zhang
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- School of PhysicsInstitute of Quantitative BiologyZhejiang UniversityHangzhou310029China
| | - Zhenming Xie
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Ning Yu
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Chunhui Cai
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Cheng Huang
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Jie Zhao
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Furong Zhang
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
| | - Yuejin Hua
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- Cancer CenterZhejiang UniversityHangzhou310029China
| | - Ye Zhao
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- Cancer CenterZhejiang UniversityHangzhou310029China
| | - Ruhong Zhou
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- Shanghai Institute for Advanced Study of Zhejiang UniversityShanghai201203China
- School of PhysicsInstitute of Quantitative BiologyZhejiang UniversityHangzhou310029China
- Cancer CenterZhejiang UniversityHangzhou310029China
| | - Bing Tian
- Institute of BiophysicsCollege of Life SciencesZhejiang UniversityHangzhou310029China
- Cancer CenterZhejiang UniversityHangzhou310029China
| |
Collapse
|
2
|
Jeong S, Singh H, Jung JH, Jung KW, Ryu S, Lim S. Comparative genomics of Deinococcus radiodurans: unveiling genetic discrepancies between ATCC 13939K and BAA-816 strains. Front Microbiol 2024; 15:1410024. [PMID: 38962131 PMCID: PMC11219805 DOI: 10.3389/fmicb.2024.1410024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2024] [Accepted: 06/04/2024] [Indexed: 07/05/2024] Open
Abstract
The Deinococcus genus is renowned for its remarkable resilience against environmental stresses, including ionizing radiation, desiccation, and oxidative damage. This resilience is attributed to its sophisticated DNA repair mechanisms and robust defense systems, enabling it to recover from extensive damage and thrive under extreme conditions. Central to Deinococcus research, the D. radiodurans strains ATCC BAA-816 and ATCC 13939 facilitate extensive studies into this remarkably resilient genus. This study focused on delineating genetic discrepancies between these strains by sequencing our laboratory's ATCC 13939 specimen (ATCC 13939K) and juxtaposing it with ATCC BAA-816. We uncovered 436 DNA sequence differences within ATCC 13939K, including 100 single nucleotide variations, 278 insertions, and 58 deletions, which could induce frameshifts altering protein-coding genes. Gene annotation revisions accounting for gene fusions and the reconciliation of gene lengths uncovered novel protein-coding genes and refined the functional categorizations of established ones. Additionally, the analysis pointed out genome structural variations due to insertion sequence (IS) elements, underscoring the D. radiodurans genome's plasticity. Notably, ATCC 13939K exhibited a loss of six ISDra2 elements relative to BAA-816, restoring genes fragmented by ISDra2, such as those encoding for α/β hydrolase and serine protease, and revealing new open reading frames, including genes imperative for acetoin decomposition. This comparative genomic study offers vital insights into the metabolic capabilities and resilience strategies of D. radiodurans.
Collapse
Affiliation(s)
- Soyoung Jeong
- Radiation Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Food and Animal Biotechnology, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Harinder Singh
- Department of Biological Sciences, Sunandan Divatia School of Science, NMIMS Deemed to be University, Mumbai, India
| | - Jong-Hyun Jung
- Radiation Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Kwang-Woo Jung
- Radiation Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
| | - Sangryeol Ryu
- Department of Food and Animal Biotechnology, Seoul National University, Seoul, Republic of Korea
- Department of Agricultural Biotechnology, Seoul National University, Seoul, Republic of Korea
| | - Sangyong Lim
- Radiation Biotechnology Division, Korea Atomic Energy Research Institute, Jeongeup, Republic of Korea
- Department of Radiation Science, University of Science and Technology, Daejeon, Republic of Korea
| |
Collapse
|
3
|
Dai S, Xie Z, Wang B, Ye R, Ou X, Wang C, Yu N, Huang C, Zhao J, Cai C, Zhang F, Buratto D, Khan T, Qiao Y, Hua Y, Zhou R, Tian B. An inorganic mineral-based protocell with prebiotic radiation fitness. Nat Commun 2023; 14:7699. [PMID: 38052788 DOI: 10.1038/s41467-023-43272-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2023] [Accepted: 11/06/2023] [Indexed: 12/07/2023] Open
Abstract
Protocell fitness under extreme prebiotic conditions is critical in understanding the origin of life. However, little is known about protocell's survival and fitness under prebiotic radiations. Here we present a radioresistant protocell model based on assembly of two types of coacervate droplets, which are formed through interactions of inorganic polyphosphate (polyP) with divalent metal cation and cationic tripeptide, respectively. Among the coacervate droplets, only the polyP-Mn droplet is radiotolerant and provides strong protection for recruited proteins. The radiosensitive polyP-tripeptide droplet sequestered with both proteins and DNA could be encapsulated inside the polyP-Mn droplet, and form into a compartmentalized protocell. The protocell protects the inner nucleoid-like condensate through efficient reactive oxygen species' scavenging capacity of intracellular nonenzymic antioxidants including Mn-phosphate and Mn-peptide. Our results demonstrate a radioresistant protocell model with redox reaction system in response to ionizing radiation, which might enable the protocell fitness to prebiotic radiation on the primitive Earth preceding the emergence of enzyme-based fitness. This protocell might also provide applications in synthetic biology as bioreactor or drug delivery system.
Collapse
Affiliation(s)
- Shang Dai
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
- Shanghai Institute for Advanced Study of Zhejiang University, Shanghai, China
| | - Zhenming Xie
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Binqiang Wang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Rui Ye
- School of Physics, Institute of Quantitative Biology, Zhejiang University, Hangzhou, China
| | - Xinwen Ou
- School of Physics, Institute of Quantitative Biology, Zhejiang University, Hangzhou, China
| | - Chen Wang
- College of Pharmaceutical Science, Zhejiang University, Hangzhou, China
| | - Ning Yu
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Cheng Huang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jie Zhao
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Chunhui Cai
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Furong Zhang
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Damiano Buratto
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
- School of Physics, Institute of Quantitative Biology, Zhejiang University, Hangzhou, China
| | - Taimoor Khan
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China
- School of Physics, Institute of Quantitative Biology, Zhejiang University, Hangzhou, China
| | - Yan Qiao
- Institute of Chemistry, Chinese Academy of Sciences, Beijing, China.
| | - Yuejin Hua
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.
- Qian Xuesen Collaborative Research Center of Astrochemistry and Space Life Sciences, Ningbo University, Ningbo, China.
- Cancer Center, Zhejiang University, Hangzhou, China.
| | - Ruhong Zhou
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.
- Shanghai Institute for Advanced Study of Zhejiang University, Shanghai, China.
- School of Physics, Institute of Quantitative Biology, Zhejiang University, Hangzhou, China.
- Cancer Center, Zhejiang University, Hangzhou, China.
| | - Bing Tian
- Institute of Biophysics, College of Life Sciences, Zhejiang University, Hangzhou, China.
- Cancer Center, Zhejiang University, Hangzhou, China.
| |
Collapse
|
4
|
Sadowska-Bartosz I, Bartosz G. Antioxidant defense of Deinococcus radiodurans: how does it contribute to extreme radiation resistance? Int J Radiat Biol 2023; 99:1803-1829. [PMID: 37498212 DOI: 10.1080/09553002.2023.2241895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/28/2023] [Accepted: 07/08/2023] [Indexed: 07/28/2023]
Abstract
PURPOSE Deinococcus radiodurans is an extremely radioresistant bacterium characterized by D10 of 10 kGy, and able to grow luxuriantly under chronic ionizing radiation of 60 Gy/h. The aim of this article is to review the antioxidant system of D. radiodurans and its possible role in the unusual resistance of this bacterium to ionizing radiation. CONCLUSIONS The unusual radiation resistance of D. radiodurans has apparently evolved as a side effect of the adaptation of this extremophile to other damaging environmental factors, especially desiccation. The antioxidant proteins and low-molecular antioxidants (especially low-molecular weight Mn2+ complexes and carotenoids, in particular, deinoxanthin), as well as protein and non-protein regulators, are important for the antioxidant defense of this species. Antioxidant protection of proteins from radiation inactivation enables the repair of DNA damage caused by ionizing radiation.
Collapse
Affiliation(s)
- Izabela Sadowska-Bartosz
- Laboratory of Analytical Biochemistry, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszow, Rzeszow, Poland
| | - Grzegorz Bartosz
- Department of Bioenergetics, Food Analysis and Microbiology, Institute of Food Technology and Nutrition, College of Natural Sciences, University of Rzeszow, Rzeszow, Poland
| |
Collapse
|
5
|
The radioresistant and survival mechanisms of Deinococcus radiodurans. RADIATION MEDICINE AND PROTECTION 2023. [DOI: 10.1016/j.radmp.2023.03.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/07/2023] Open
|
6
|
Wan W, Grossart H, He D, Liu W, Wang S, Yang Y. Differentiation strategies for planktonic bacteria and eukaryotes in response to aggravated algal blooms in urban lakes. IMETA 2023; 2:e84. [PMID: 38868338 PMCID: PMC10989909 DOI: 10.1002/imt2.84] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 01/06/2023] [Accepted: 01/09/2023] [Indexed: 06/14/2024]
Abstract
Aggravated algal blooms potentially decreased environmental heterogeneity. Different strategies of planktonic bacteria and eukaryotes in response to aggravated algal blooms. Environmental constraints of plankton showed different patterns over time.
Collapse
Affiliation(s)
- Wenjie Wan
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhanPeople's Republic of China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research StationChinese Academy of Sciences & Hubei ProvinceWuhanPeople's Republic of China
| | - Hans‐Peter Grossart
- Departent of Plankton and Microbial EcologyLeibniz‐Institute for Freshwater Ecology and Inland Fisheries (IGB)NeuglobsowGermany
- Institute of Biochemistry and BiologyUniversity of PotsdamPotsdamGermany
| | - Donglan He
- College of Life ScienceSouth‐Central Minzu UniversityWuhanPeople's Republic of China
| | - Wenzhi Liu
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhanPeople's Republic of China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research StationChinese Academy of Sciences & Hubei ProvinceWuhanPeople's Republic of China
| | - Shuai Wang
- College of Life ScienceSouth‐Central Minzu UniversityWuhanPeople's Republic of China
| | - Yuyi Yang
- Key Laboratory of Aquatic Botany and Watershed Ecology Wuhan Botanical GardenChinese Academy of SciencesWuhanPeople's Republic of China
- Danjiangkou Wetland Ecosystem Field Scientific Observation and Research StationChinese Academy of Sciences & Hubei ProvinceWuhanPeople's Republic of China
| |
Collapse
|
7
|
M S, N RP, Rajendrasozhan S. Bacterial redox response factors in the management of environmental oxidative stress. World J Microbiol Biotechnol 2022; 39:11. [PMID: 36369499 DOI: 10.1007/s11274-022-03456-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Accepted: 11/02/2022] [Indexed: 11/13/2022]
Abstract
Bacteria evolved to survive in the available environmental chemosphere via several cellular mechanisms. A rich pool of antioxidants and stress regulators plays a significant role in the survival of bacteria in unfavorable environmental conditions. Most of the microbes exhibit resistant phenomena in toxic environment niches. Naturally, bacteria possess efficient thioredoxin reductase, glutaredoxin, and peroxiredoxin redox systems to handle environmental oxidative stress. Further, an array of transcriptional regulators senses the oxidative stress conditions. Transcription regulators, such as OxyR, SoxRS, PerR, UspA, SsrB, MarA, OhrR, SarZ, etc., sense and transduce bacterial oxidative stress responses. The redox-sensitive transcription regulators continuously recycle the utilized antioxidant enzymes during oxidative stress. These regulators promote the expression of antioxidant enzymes such as superoxide dismutase, catalase, and peroxides that overcome oxidative insults. Therefore, the transcriptional regulations maintain steady-state activities of antioxidant enzymes representing the resistance against host cell/environmental oxidative insults. Further, the redox system provides reducing equivalents to synthesize biomolecules, thereby contributing to cellular repair mechanisms. The inactive transcriptional regulators in the undisturbed cells are activated by oxidative stress. The oxidized transcriptional regulators modulate the expression of antioxidant and cellular repair enzymes to survive in extreme environmental conditions. Therefore, targeting these antioxidant systems and response regulators could alter cellular redox homeostasis. This review presents the mechanisms of different redox systems that favor bacterial survival in extreme environmental oxidative stress conditions.
Collapse
Affiliation(s)
- Sudharsan M
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India
| | - Rajendra Prasad N
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, Chidambaram, Tamil Nadu, 608 002, India.
| | | |
Collapse
|
8
|
Exopolyphosphatases PPX1 and PPX2 from Mycobacterium tuberculosis regulate dormancy response and pathogenesis. Microb Pathog 2022; 173:105885. [DOI: 10.1016/j.micpath.2022.105885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/12/2022] [Accepted: 11/12/2022] [Indexed: 11/21/2022]
|
9
|
M S, N RP, Chakraborty A, Rajendrasozhan S. Proteomic profiling of Deinococcus radiodurans with response to thioredoxin reductase inhibitor and ionizing radiation treatment. J Proteomics 2022; 267:104697. [PMID: 35995383 DOI: 10.1016/j.jprot.2022.104697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 08/05/2022] [Accepted: 08/10/2022] [Indexed: 11/27/2022]
Abstract
This study explains the importance of cellular redox system in preserving the proteome of the radioresistant Deinococcus radiodurans. The thioredoxin reductase (TrxR) redox system was inhibited by ebselen (10 μM), and then the bacterium was exposed to 4 kGy of ionizing radiation. The differentially expressed proteins were analyzed using label-free quantitative (LFQ) proteomics. The 4 kGy radiation treatment increases the expression of stress response proteins like osmotically inducible protein OsmC, catalase, and metallophosphoesterase compared to control. Ebselen plus radiation treatment augments oxidoreductases proteins in D. radiodurans. Further, the proteins involved in glycolysis, tricarboxylic acetic acid (TCA) and proteins like proteases, peptidase, and peptide transporters were significantly decreased in the ebselen plus radiation group compared to radiation treated group. Further, ebselen plus radiation treatment increases the ATP-binding cassette (ABC) transporters involved in the efflux of toxic chemicals and nutrient uptake and the stress response related membrane protein like S-layer homology domain-containing protein in D. radiodurans. Thus, the results show that the altered redox status via inhibition of TrxR redox system significantly affects the expression of essential cellular proteins for the survival. The cellular content of D. radiodurans may be used to handle redox imbalances in the normal cells during cancer radiotherapy. SIGNIFICANCE: Deinococcus radiodurans is a popular radioresistance organism with efficient antioxidant systems and DNA repair mechanisms. There are many antioxidant systems and small molecules that responsible for its resistance. The importance of thiol based antioxidant systems in its resistance property has not fully studied yet. Thioredoxin reductase is an important disulfide containing protein that involved in maintaining redox homeostasis. The TrxR inhibition affects the cell survival and synthesis of molecules against ionizing radiation. In this study we are reporting the effects of TrxR inhibitor on proteome of D. radiodurans upon ionizing radiation. This study reveals the significance of TrxR antioxidant system on the proteome of D. radiodurans. The inhibition of TrxR antioxidant system and the subsequent disturbances in the proteome content makes the organism vulnerable to oxidative stress.
Collapse
Affiliation(s)
- Sudharsan M
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, 608 002, Tamilnadu, India
| | - Rajendra Prasad N
- Department of Biochemistry and Biotechnology, Annamalai University, Annamalainagar, 608 002, Tamilnadu, India
| | - Anindita Chakraborty
- UGC-DAE Consortium for Scientific Research, Kolkata Centre, 700098, West Bengal, India
| | | |
Collapse
|
10
|
PerR-Regulated Manganese Import Contributes to Oxidative Stress Defense in Streptococcus suis. Appl Environ Microbiol 2022; 88:e0008622. [PMID: 35465691 DOI: 10.1128/aem.00086-22] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Streptococcus suis has been increasingly recognized as a porcine zoonotic pathogen that threatens the health of both pigs and humans. Metal homeostasis plays a critical role in the antioxidative capability of bacteria, thus facilitating the escape of pathogenic species from the innate immunity systems of hosts. Here, we revealed that manganese increased the ability of S. suis to resist oxidative stress. RNA sequencing was used to identify potential candidate genes involved in the maintenance of intracellular manganese homeostasis. Four genes, termed troABCD, were identified by NCBI BLASTp analysis. The troA, troB, troC, and troD deletion mutant strains exhibited decreased intracellular manganese content and tolerance to H2O2 compared to the wild-type strain. Thus, troABCD were determined to be involved in manganese uptake and played an important role in H2O2 tolerance in S. suis. Furthermore, the inactivation of perR increased the survival of H2O2-pulsed S. suis 2.18-fold and elevated the intracellular manganese content. H2O2-pulsed S. suis and perR deletion mutants upregulated troABCD. This finding suggested that H2O2 released the suppression of troABCD by perR. In addition, an electrophoretic mobility shift assay (EMSA) showed that PerR at 500 ng binds to the troABCD promoter, indicating that troABCD were directly regulated by PerR. In conclusion, this study revealed that manganese increases tolerance to H2O2 by upregulating the expression of troABCD. Moreover, PerR-regulated Mn import in S. suis and increased the tolerance of S. suis to oxidative stress by regulating troABCD. IMPORTANCE During infection, it is extremely important for bacteria to defend against oxidative stress. While manganese plays an important role in this process, its role is unclear in S. suis. Here, we demonstrated that manganese increased S. suis tolerance to oxidative stress. Four manganese ABC transporter genes, troABCD, were identified. Oxidative stress increased the content of manganese in the cell. Furthermore, PerR increased the tolerance to oxidative stress of S. suis by regulating troABCD. Manganese played an important role in bacterial defense against oxidative stress. These findings provide novel insight into the mechanism by which S. suis resists oxidative stress and approaches to inhibit bacterial infection by limiting manganese intake.
Collapse
|
11
|
Dai S, Ye R, Huang J, Wang B, Xie Z, Ou X, Yu N, Huang C, Hua Y, Zhou R, Tian B. Distinct lipid membrane interaction and uptake of differentially charged nanoplastics in bacteria. J Nanobiotechnology 2022; 20:191. [PMID: 35428303 PMCID: PMC9011954 DOI: 10.1186/s12951-022-01321-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/21/2022] [Indexed: 11/12/2022] Open
Abstract
Background Nanoplastics have been recently found widely distributed in our natural environment where ubiquitously bacteria are major participants in various material cycles. Understanding how nanoplastics interact with bacterial cell membrane is critical to grasp their uptake processes as well as to analyze their associated risks in ecosystems and human microflora. However, little is known about the detailed interaction of differentially charged nanoplastics with bacteria. The present work experimentally and theoretically demonstrated that nanoplastics enter into bacteria depending on the surface charges and cell envelope structural features, and proved the shielding role of membrane lipids against nanoplastics. Results Positively charged polystyrene nanoplastics (PS-NH2, 80 nm) can efficiently translocate across cell membranes, while negatively charged PS (PS-COOH) and neutral PS show almost no or much less efficacy in translocation. Molecular dynamics simulations revealed that the PS-NH2 displayed more favourable electrostatic interactions with bacterial membranes and was subjected to internalisation through membrane penetration. The positively charged nanoplastics destroy cell envelope of Gram-positive B. subtilis by forming membrane pore, while enter into the Gram-negative E. coli with a relatively intact envelope. The accumulated positively charged nanoplastics conveyed more cell stress by inducing a higher level of reactive oxygen species (ROS). However, the subsequently released membrane lipid-coated nanoplastics were nearly nontoxic to cells, and like wise, stealthy bacteria wrapped up with artifical lipid layers became less sensitive to the positively charged nanoplastics, thereby illustrating that the membrane lipid can shield the strong interaction between the positively charged nanoplastics and cells. Conclusions Our findings elucidated the molecular mechanism of nanoplastics’ interaction and accumulation within bacteria, and implied the shielding and internalization effect of membrane lipid on toxic nanoplastics could promote bacteria for potential plastic bioremediation. Graphical Abstract ![]()
Supplementary Information The online version contains supplementary material available at 10.1186/s12951-022-01321-z.
Collapse
|
12
|
Zhang HC, Zhang R, Shi H. The effect of manganese and iron on mediating resuscitation of lactic acid-injured Escherichia coli. Lett Appl Microbiol 2022; 75:161-170. [PMID: 35395105 DOI: 10.1111/lam.13715] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2021] [Revised: 03/28/2022] [Accepted: 03/29/2022] [Indexed: 01/05/2023]
Abstract
Lactic acid can induce sublethal injury of E. coli through oxidative stress. In this study, we investigated changes in SOD activity, CAT activity, GSH production and ROS production during sublethal injury and resuscitation of E. coli. Then, the effect of manganese and iron during resuscitation were studied. Both cations (≥1 mmol l-1 ) significantly promoted the resuscitation of sublethally injured E. coli induced by lactic acid and shortened the repair time (P < 0·05). Conversely, addition of N,N,N',N'-tetrakis (2-pyridylmethyl) which is a metal chelator extended the repair time. Compared with minA, manganese and iron significantly improved SOD activity at 40, 80 and 120 min and decreased ROS production at 40 and 80 min, thereby recovering injured E. coli quickly (P < 0·05). The deletion of sodA encoding Mn-SOD, sodB encoding Fe-SOD or gshA/gshB encoding GSH significantly strengthened sublethal injury and extended the repair time (P < 0·05). It meant these genes-related oxidative stress played important roles in the acid resistance of E. coli and recovery of sublethal injury. Therefore, manganese and iron can promote the recovery of lactic-injured E. coli by the way of increasing SOD activity, scavenging ROS, and relieving oxidative stress.
Collapse
Affiliation(s)
- H C Zhang
- College of Food Science, Southwest University, Chongqing, China
| | - R Zhang
- College of Food Science, Southwest University, Chongqing, China
| | - H Shi
- College of Food Science, Southwest University, Chongqing, China
| |
Collapse
|
13
|
Bowlin MQ, Long AR, Huffines JT, Gray MJ. The role of nitrogen-responsive regulators in controlling inorganic polyphosphate synthesis in Escherichia coli. MICROBIOLOGY (READING, ENGLAND) 2022; 168:001185. [PMID: 35482529 PMCID: PMC10233264 DOI: 10.1099/mic.0.001185] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2022] [Accepted: 04/10/2022] [Indexed: 12/22/2022]
Abstract
Inorganic polyphosphate (polyP) is synthesized by bacteria under stressful environmental conditions and acts by a variety of mechanisms to promote cell survival. While the kinase that synthesizes polyP (PPK, encoded by the ppk gene) is well known, ppk transcription is not activated by environmental stress and little is understood about how environmental stress signals lead to polyP accumulation. Previous work has shown that the transcriptional regulators DksA, RpoN (σ54) and RpoE (σ24) positively regulate polyP production, but not ppk transcription, in Escherichia coli. In this work, we examine the role of the alternative sigma factor RpoN and nitrogen starvation stress response pathways in controlling polyP synthesis. We show that the RpoN enhancer binding proteins GlnG and GlrR impact polyP production, and uncover a new role for the nitrogen phosphotransferase regulator PtsN (EIIANtr) as a positive regulator of polyP production, acting upstream of DksA, downstream of RpoN and apparently independently of RpoE. However, neither these regulatory proteins nor common nitrogen metabolites appear to act directly on PPK, and the precise mechanism(s) by which polyP production is modulated after stress remain(s) unclear. Unexpectedly, we also found that the genes that impact polyP production vary depending on the composition of the rich media in which the cells were grown before exposure to polyP-inducing stress. These results constitute progress towards deciphering the regulatory networks driving polyP production under stress, and highlight the remarkable complexity of this regulation and its connections to a broad range of stress-sensing pathways.
Collapse
Affiliation(s)
- Marvin Q. Bowlin
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Abagail Renee Long
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Joshua T. Huffines
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| | - Michael Jeffrey Gray
- Department of Microbiology, Heersink School of Medicine, University of Alabama at Birmingham, Birmingham, AL 35294, USA
| |
Collapse
|
14
|
Small-Molecule Mn Antioxidants in Caenorhabditis elegans and Deinococcus radiodurans Supplant MnSOD Enzymes during Aging and Irradiation. mBio 2022; 13:e0339421. [PMID: 35012337 PMCID: PMC8749422 DOI: 10.1128/mbio.03394-21] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Denham Harman's oxidative damage theory identifies superoxide (O2•-) radicals as central agents of aging and radiation injury, with Mn2+-dependent superoxide dismutase (MnSOD) as the principal O2•--scavenger. However, in the radiation-resistant nematode Caenorhabditis elegans, the mitochondrial antioxidant enzyme MnSOD is dispensable for longevity, and in the model bacterium Deinococcus radiodurans, it is dispensable for radiation resistance. Many radiation-resistant organisms accumulate small-molecule Mn2+-antioxidant complexes well-known for their catalytic ability to scavenge O2•-, along with MnSOD, as exemplified by D. radiodurans. Here, we report experiments that relate the MnSOD and Mn-antioxidant content to aging and oxidative stress resistances and which indicate that C. elegans, like D. radiodurans, may rely on Mn-antioxidant complexes as the primary defense against reactive oxygen species (ROS). Wild-type and ΔMnSOD D. radiodurans and C. elegans were monitored for gamma radiation sensitivities over their life spans while gauging Mn2+-antioxidant content by electron paramagnetic resonance (EPR) spectroscopy, a powerful new approach to determining the in vivo Mn-antioxidant content of cells as they age. As with D. radiodurans, MnSOD is dispensable for radiation survivability in C. elegans, which hyperaccumulates Mn-antioxidants exceptionally protective of proteins. Unexpectedly, ΔMnSOD mutants of both the nematodes and bacteria exhibited increased gamma radiation survival compared to the wild-type. In contrast, the loss of MnSOD renders radiation-resistant bacteria sensitive to atmospheric oxygen during desiccation. Our results support the concept that the disparate responses to oxidative stress are explained by the accumulation of Mn-antioxidant complexes which protect, complement, and can even supplant MnSOD. IMPORTANCE The current theory of cellular defense against oxidative damage identifies antioxidant enzymes as primary defenders against ROS, with MnSOD being the preeminent superoxide (O2•-) scavenger. However, MnSOD is shown to be dispensable both for radiation resistance and longevity in model organisms, the bacterium Deinococcus radiodurans and the nematode Caenorhabditis elegans. Measured by electron paramagnetic resonance (EPR) spectroscopy, small-molecule Mn-antioxidant content was shown to decline in unison with age-related decreases in cell proliferation and radioresistance, which again are independent of MnSOD presence. Most notably, the Mn-antioxidant content of C. elegans drops precipitously in the last third of its life span, which links with reports that the steady-state level of oxidized proteins increases exponentially during the last third of the life span in animals. This leads us to propose that global responses to oxidative stress must be understood through an extended theory that includes small-molecule Mn-antioxidants as potent O2•--scavengers that complement, and can even supplant, MnSOD.
Collapse
|