Journal of Microbiology

Full article

Encapsulin protein MAV2054 enhances Mycobacterium avium virulence by promoting Cdc42-dependent epithelial cell invasion: Dong Ho Kim, I Jeong Jo, Min Ju Kang, Yi Seol Kim, Duyen Do Tran Huong, Kyungho Woo, Ho-Sung Park, Hwa-Jung Kim, Chul Hee Choi; J. Microbiol. 2025;63(11):e2506008. Published online November 30, 2025; DOI: https://doi.org/10.71150/jm.2506008

137 View
1 Download

Abstract PDF: Mycobacterium avium complex (MAC) organisms are widespread environmental pathogens associated with chronic pulmonary infections. Although M. avium is known to invade epithelial cells, the molecular mechanisms underlying this process remain incompletely understood. In this study, we identified a novel role for MAVRS09815 (formerly MAV2054), a family 2A encapsulin nanocompartment shell protein, in mediating bacterial adhesion, epithelial cell invasion, and in vivo virulence. We engineered a recombinant M. smegmatis strain expressing MAV2054 (Ms_2054) and an M. avium MAV2054 deletion mutant (Δ2054). Ms_2054 exhibited enhanced epithelial invasion, whereas Δ2054 showed reduced intracellular survival. Recombinant MAV2054 protein was bound directly to human epithelial cells in a dose-dependent manner. Pretreatment of host cells with cytochalasin D or vinblastine significantly inhibited bacterial internalization, indicating that MAV2054-mediated invasion is cytoskeleton-dependent. Confocal and scanning electron microscopy revealed MAV2054-dependent membrane rearrangements during infection. Pull-down assays demonstrated that MAV2054 activates Cdc42, a key regulator of actin polymerization, with reduced activation observed in Δ2054-infected cells. In a murine intratracheal infection model, the Δ2054 exhibited significantly reduced bacterial burdens and lung inflammation compared to the wild type. These findings demonstrate that MAV2054 enhances M. avium virulence by promoting epithelial cell invasion through Cdc42-dependent cytoskeletal remodeling. This study reveals a previously unrecognized role for an encapsulin-like protein in host-pathogen interactions and highlights its potential as a therapeutic target in MAC infections.

Reviews

The osmotic stress response operon betIBA is under the functional regulation of BetI and the quorum-sensing regulator AnoR in Acinetobacter nosocomialis: Bindu Subhadra , Surya Surendran , Bo Ra Lim , Jong Sung Yim , Dong Ho Kim , Kyungho Woo , Hwa-Jung Kim , Man Hwan Oh , Chul Hee Choi; J. Microbiol. 2020;58(6):519-529. Published online May 27, 2020; DOI: https://doi.org/10.1007/s12275-020-0186-1

370 View
0 Download
16 Web of Science
15 Crossref

Adaptation to changing environmental conditions is crucial for the survival of microorganisms. Bacteria have evolved various mechanisms to cope with osmotic stress. Here, we report the identification and functional characterization of the osmotic stress response operon, betIBA, in Acinetobacter nosocomialis. The betIBA operon encodes enzymes that are important for the conversion of choline to the osmoprotectant, glycine betaine. The betIBA operon is polycistronic and is under the regulation of the first gene, betI, of the same operon. A bioinformatics analysis revealed the presence of a BetI-binding motif upstream of the betIBA operon, and electrophoretic mobility shift assays confirmed the specific binding of BetI. An mRNA expression analysis revealed that expression of betI, betB, and betA genes is elevated in a betIeletion mutant compared with the wild type, confirming that the autorepressor BetI represses the betIBA operon in A. nosocomialis. We further found that the betIBA operon is under the transcriptional control of the quorum-sensing (QS) regulator, AnoR in, A. nosocomialis. A subsequent analysis of the impact of BetI on expression of the QS genes, anoR and anoI, demonstrated that BetI acts as a repressor of anoR and anoI. In addition, it was noticed that the osmotic stress response regulator, OmpR might play an important role in controlling the expression of betIBA operon in A. nosocomialis. Collectively, these data demonstrate that QS and osmotic stress-response systems are correlated in A. nosocomialis and that the expression of genes in both systems is finely tuned by various feedback loops depending on osmolarity conditions.

Citations

Citations to this article as recorded by

Comamonas halotolerans sp. nov., isolated from the faecal sample of a zoo animal, Naemorhedus caudatus
Yerim Park, Bitnara Kim, Jihyeon Min, Woojun Park
International Journal of Systematic and Evolutionary Microbiology .2025;[Epub] CrossRef
Plant Growth-Promoting Effect and Complete Genomic Sequence Analysis of the Beneficial Rhizosphere Streptomyces sp. GD-4 Isolated from Leymus secalinus
Wanru Xu, Yimeng Liu, Yiping Cheng, Jie Zhang
Microorganisms.2025; 13(2): 286. CrossRef
Comparative genomic analysis of 255 Oenococcus oeni isolates from China: unveiling strain diversity and genotype-phenotype associations of acid resistance
Wei Chi, Hanwen Zhang, Xinyi Li, Yeqin Zhou, Qiang Meng, Ling He, Yafan Yang, Shuwen Liu, Kan Shi, Feng Gao
Microbiology Spectrum.2025;[Epub] CrossRef
Potential mode of action of multispecies inoculums on wheat growth under water stress
Asmaâ Agoussar, Julien Tremblay, Étienne Yergeau
ISME Communications.2025;[Epub] CrossRef
A Novel Phosphorus-Recovering Bacterium Pelagibacterium mangrovi sp. nov., Isolated from Mangrove Sediment
Shang Yang, Guohong Liu, Ruili Li, Wei Yu, Yuefei Huang, Xiaofeng Wu, Shungui Zhou, Bing Li
Current Microbiology.2025;[Epub] CrossRef
Novel regulatory mechanism of choline-O-sulfate and choline catabolism by two BetIs in Alphaproteobacteria
Jia-Rong Liu, Zhen-Kun Li, Ming-Chen Wang, Na Wang, Zhi-Qing Wang, Fei-Fei Li, Yin Chen, Yu-Zhong Zhang, Hui-Hui Fu, Arpita Bose
Applied and Environmental Microbiology.2025;[Epub] CrossRef
Metabolome analysis revealed the critical role of betaine for arsenobetaine biosynthesis in the marine medaka (Oryzias melastigma)
Qianyu Zhao, Qiao-Guo Tan, Wen-Xiong Wang, Peng Zhang, Zijun Ye, Liping Huang, Wei Zhang
Environmental Pollution.2024; 359: 124612. CrossRef
The atypical organization of the luxI/R family genes in AHL-driven quorum-sensing circuits
Yuyuan Cai, Xuehong Zhang, Michael J. Federle
Journal of Bacteriology.2024;[Epub] CrossRef
The Transcriptomic Response of Cells of the Thermophilic Bacterium Geobacillus icigianus to Terahertz Irradiation
Sergey Peltek, Svetlana Bannikova, Tamara M. Khlebodarova, Yulia Uvarova, Aleksey M. Mukhin, Gennady Vasiliev, Mikhail Scheglov, Aleksandra Shipova, Asya Vasilieva, Dmitry Oshchepkov, Alla Bryanskaya, Vasily Popik
International Journal of Molecular Sciences.2024; 25(22): 12059. CrossRef
Mycobacterium smegmatis MraZ Regulates Multiple Genes within and Outside of the dcw Operon during Hypoxia
Ismail Mohamed Suleiman, Huang Yu, Junqi Xu, Junfeng Zhen, Hongxiang Xu, Abulimiti Abudukadier, Amina Rafique Hafiza, Jianping Xie
ACS Infectious Diseases.2024; 10(12): 4301. CrossRef
Online Omics Platform Expedites Industrial Application of Halomonas bluephagenesis TD1.0
Helen Park, Matthew Faulkner, Helen S Toogood, Guo-Qiang Chen, Nigel Scrutton
Bioinformatics and Biology Insights.2023;[Epub] CrossRef
The Effect of Proline on the Freeze-Drying Survival Rate of Bifidobacterium longum CCFM 1029 and Its Inherent Mechanism
Shumao Cui, Wenrui Zhou, Xin Tang, Qiuxiang Zhang, Bo Yang, Jianxin Zhao, Bingyong Mao, Hao Zhang
International Journal of Molecular Sciences.2022; 23(21): 13500. CrossRef
Regulator of RNase E activity modulates the pathogenicity of Salmonella Typhimurium
Jaejin Lee, Eunkyoung Shin, Ji-Hyun Yeom, Jaeyoung Park, Sunwoo Kim, Minho Lee, Kangseok Lee
Microbial Pathogenesis.2022; 165: 105460. CrossRef
The Flagellar Transcriptional Regulator FtcR Controls Brucella melitensis 16M Biofilm Formation via a betI-Mediated Pathway in Response to Hyperosmotic Stress
Jia Guo, Xingmei Deng, Yu Zhang, Shengnan Song, Tianyi Zhao, Dexin Zhu, Shuzhu Cao, Peter Ivanovic Baryshnikov, Gang Cao, Hugh T. Blair, Chuangfu Chen, Xinli Gu, Liangbo Liu, Hui Zhang
International Journal of Molecular Sciences.2022; 23(17): 9905. CrossRef
Stressed out: Bacterial response to high salinity using compatible solute biosynthesis and uptake systems, lessons from Vibrionaceae
Gwendolyn J. Gregory, E. Fidelma Boyd
Computational and Structural Biotechnology Journal.2021; 19: 1014. CrossRef

Regulation of the AcrAB efflux system by the quorum-sensing regulator AnoR in Acinetobacter nosocomialis: Bindu Subhadra , Surya Surendran , Bo Ra Lim , Jong Sung Yim , Dong Ho Kim , Kyungho Woo , Hwa-Jung Kim , Man Hwan Oh , Chul Hee Choi; J. Microbiol. 2020;58(6):507-518. Published online May 27, 2020; DOI: https://doi.org/10.1007/s12275-020-0185-2

341 View
0 Download
13 Web of Science
11 Crossref

Abstract PDF

Multidrug efflux pumps play an important role in antimicrobial resistance and pathogenicity in bacteria. Here, we report the functional characterization of the RND (resistance-nodulation- division) efflux pump, AcrAB, in Acinetobacter nosocomialis. An in silico analysis revealed that homologues of the AcrAB efflux pump, comprising AcrA and AcrB, are widely distributed among different bacterial species. Deletion of acrA and/or acrB genes led to decreased biofilm/pellicle formation and reduced antimicrobial resistance in A. nosocomialis. RNA sequencing and mRNA expression analyses showed that expression of acrA/B was downregulated in a quorum sensing (QS) regulator (anoR)-deletion mutant, indicating transcriptional activation of the acrAB operon by AnoR in A. nosocomialis. Bioassays showed that secretion of N-acyl homoserine lactones (AHLs) was unaffected in acrA and acrB deletion mutants; however, AHL secretion was limited in a deletion mutant of acrR, encoding the acrAB regulator, AcrR. An in silico analysis indicated the presence of AcrR-binding motifs in promoter regions of anoI (encoding AHL synthase) and anoR. Specific binding of AcrR was confirmed by electrophoretic mobility shift assays, which revealed that AcrR binds to positions -214 and -217 bp upstream of the translational start sites of anoI and anoR, respectively, demonstrating transcriptional regulation of these QS genes by AcrR. The current study further addresses the possibility that AcrAB is controlled by the osmotic stress regulator, OmpR, in A. nosocomialis. Our data demonstrate that the AcrAB efflux pump plays a crucial role in biofilm/pellicle formation and antimicrobial resistance in A. nosocomialis, and is under the transcriptional control of a number of regulators. In addition, the study emphasizes the interrelationship of QS and AcrAB efflux systems in A. nosocomialis.

Citations

Citations to this article as recorded by

Types and Mechanisms of Efflux Pump Systems and the Potential of Efflux Pump Inhibitors in the Restoration of Antimicrobial Susceptibility, with a Special Reference to Acinetobacter baumannii
Kira M. Zack, Trent Sorenson, Suresh G. Joshi
Pathogens.2024; 13(3): 197. CrossRef
Lysine Trimethylation in Planktonic and Pellicle Modes of Growth in Acinetobacter baumannii
Nicolas Nalpas, Takfarinas Kentache, Emmanuelle Dé, Julie Hardouin
Journal of Proteome Research.2023; 22(7): 2339. CrossRef
The Mechanism of Tigecycline Resistance in Acinetobacter baumannii Revealed by Proteomic and Genomic Analysis
Cunwei Liu, Lei Wang, Ping Wang, Di Xiao, Qinghua Zou
International Journal of Molecular Sciences.2023; 24(10): 8652. CrossRef
Antimicrobial photodynamic therapy against oral biofilm: influencing factors, mechanisms, and combined actions with other strategies
Yijun Li, Guanwen Sun, Jingchan Xie, Suli Xiao, Chen Lin
Frontiers in Microbiology.2023;[Epub] CrossRef
The multifaceted genusAcinetobacter: from infection to bioremediation
Ujwal Dahal, Karan Paul, Shelly Gupta
Journal of Applied Microbiology.2023;[Epub] CrossRef
Efflux pumps and microbial biofilm formation
Mahdyeh Neghabi Hajiagha, Hossein Samadi Kafil
Infection, Genetics and Evolution.2023; 112: 105459. CrossRef
Targeting the Holy Triangle of Quorum Sensing, Biofilm Formation, and Antibiotic Resistance in Pathogenic Bacteria
Ronit Vogt Sionov, Doron Steinberg
Microorganisms.2022; 10(6): 1239. CrossRef
Evidence for Complex Interplay between Quorum Sensing and Antibiotic Resistance in Pseudomonas aeruginosa
Rakesh Sikdar, Mikael H. Elias, Giordano Rampioni
Microbiology Spectrum.2022;[Epub] CrossRef
Update on Multidrug Resistance Efflux Pumps in Acinetobacter spp.
Vanessa Kornelsen, Ayush Kumar
Antimicrobial Agents and Chemotherapy.2021;[Epub] CrossRef
Orthopedic Implant-Related Biofilm Pathophysiology: A Review of the Literature
Meletis Rozis, Dimitrios S Evangelopoulos, Spyros G Pneumaticos
Cureus.2021;[Epub] CrossRef
The impact of cell structure, metabolism and group behavior for the survival of bacteria under stress conditions
Xinyi Zhang, Zhendong Li, Shengmei Pang, Boyu Jiang, Yang Yang, Qiangde Duan, Guoqiang Zhu
Archives of Microbiology.2021; 203(2): 431. CrossRef

First
Prev
Page of 1
Next
Last

Search