Journal of Bacteriology最新文献

{"title":"The cell wall hydrolase MltG is essential to maintain cell wall homeostasis of <i>Enterococcus faecalis</i>.","authors":"Alexis A U Knotek, Christopher J Kristich","doi":"10.1128/jb.00056-25","DOIUrl":"https://doi.org/10.1128/jb.00056-25","url":null,"abstract":"<p><p>Infections caused by enterococci are increasingly prevalent and difficult to treat due to multidrug resistance. <i>Enterococcus faecalis</i> exhibits intrinsic resistance toward cephalosporins, which inhibit the final step of peptidoglycan (PG) synthesis. Intrinsic resistance requires multiple factors in the PG synthesis pathway and at least two cell-wall-stress signal transduction systems; however, the complete molecular mechanism of enterococcal cephalosporin resistance remains to be elucidated. MltG, a predicted PG hydrolase, is thought to process nascent strands of PG, suggesting that MltG might play an important role in enterococcal cell wall homeostasis and potentially cephalosporin resistance. Here, we demonstrate that enterococcal MltG cleaves nascent PG. An <i>E. faecalis</i> mutant lacking MltG exhibits several related phenotypes in the absence of exogenous stress: a marked growth defect, a loss of cell wall integrity, a reduction in PG synthesis, and activation of two cell-wall-stress signal transduction systems that drive elevated cephalosporin resistance. Together, these results are consistent with the model that MltG promotes proper cell wall homeostasis in <i>E. faecalis,</i> and further reveal that the enzymatic activity of MltG is not necessary for it to perform this function-instead, the LysM (putative PG-binding) domain of MltG plays the critical role. Nevertheless, the enzymatic activity of MltG does impact cephalosporin resistance, because a catalytically inactive MltG variant leads to elevated resistance. Collectively, our findings represent the first description of MltG function in <i>E. faecalis</i> and point to at least two distinct roles for MltG in PG homeostasis and cephalosporin resistance.</p><p><strong>Importance: </strong><i>Enterococcus faecalis</i> is an opportunistic pathogen that colonizes the human gut microbiome. Infections caused by <i>E. faecalis</i> are increasingly prevalent and difficult to treat due to the multidrug resistance exhibited toward common clinical antibiotics. A thorough understanding of the mechanisms used by <i>E. faecalis</i> to maintain cell wall homeostasis will serve as a foundation for future development of new therapeutics that disable enterococcal resistance to cell-wall-active antibiotics and may reveal new vulnerabilities that could be exploited by novel antimicrobials. Here, we demonstrate that the MltG peptidoglycan hydrolase is essential for enterococcal cell wall homeostasis, but that the enzymatic activity of MltG is not required for this role. Instead, the enzymatic activity of MltG impacts intrinsic resistance toward cephalosporins.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0005625"},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284480","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Molecular characterization and resistance mechanisms of ertapenem-non-susceptible carbapenem-resistant <i>Klebsiella pneumoniae</i> co-harboring ESBLs or AmpC enzymes with porin loss or efflux pump overexpression.","authors":"Yingying Su, Guangmei Zou, Xin Huang, Jinli Bi, Liqin Meng, Wei Zhao, Taijie Li","doi":"10.1128/jb.00148-25","DOIUrl":"https://doi.org/10.1128/jb.00148-25","url":null,"abstract":"<p><p>Carbapenem-resistant <i>Klebsiella pneumoniae</i> (CRKP) poses a significant challenge in clinical settings due to limited treatment options and high mortality rates. While carbapenemase-producing CRKP has been extensively studied, the mechanisms underlying resistance in non-carbapenemase-producing CRKP remain less understood. In this study, we investigated 30 ertapenem-resistant non-carbapenemase-producing CRKP clinical isolates. Antimicrobial susceptibility testing revealed multidrug resistance in all strains. Molecular analyses showed that all isolates carried extended-spectrum β-lactamase (ESBL) and/or AmpC β-lactamase genes. Sequencing of outer membrane porin (OMP) genes revealed mutations or deletions in <i>ompK35</i> and/or <i>ompK36</i> in the majority of isolates. SDS-PAGE analysis confirmed reduced or absent expression of the corresponding OMP proteins in these strains. Additionally, quantitative PCR showed that several isolates exhibited overexpression of efflux pump genes. These findings indicate that the combined effects of ESBL or AmpC production, porin loss at both the genetic and protein levels, and efflux pump overactivity contribute to ertapenem resistance in non-carbapenemase-producing CRKP. Our results underscore the complexity of resistance mechanisms and highlight the importance of integrated molecular and phenotypic assessments to inform appropriate antimicrobial therapy.</p><p><strong>Importance: </strong>This study highlights the complex, multifactorial nature of carbapenem resistance in carbapenem-resistant <i>Klebsiella pneumoniae</i> (CRKP), involving enzyme-mediated resistance, reduced membrane porin expression, and overactive efflux pumps. These findings provide valuable insights into CRKP resistance mechanisms and can aid in controlling CRKP in China.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0014825"},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284478","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The <i>Agrobacterium fabrum</i> efflux pump PecM is produced in response to the plant exudate 4-hydroxybenzaldehyde to avoid disruption of central metabolism.","authors":"Arpita Ghosh, Anne Grove","doi":"10.1128/jb.00150-25","DOIUrl":"https://doi.org/10.1128/jb.00150-25","url":null,"abstract":"<p><p><i>Agrobacterium fabrum</i> is a phytopathogen that causes crown gall disease. In the rhizosphere, it encounters plant exudates, some of which are toxic, such as 4-hydroxybenzaldehyde (4HBA). Others, including 4-hydroxybenzoate (4HB), participate in the induction of virulence genes. <i>A. fabrum</i> encodes the transcription factor PecS, which has been reported to enhance bacterial fitness in the rhizosphere. The gene encoding PecS is divergent from <i>pecM</i>, which encodes an efflux pump. PecS represses both <i>pecS</i> and <i>pecM</i>, as evidenced by increased expression in the presence of the PecS ligand urate and by elevated <i>pecM</i> expression in a <i>pecS</i> disruption strain. We report here that the expression of <i>pecM</i> is induced selectively by 4HBA. Expression of genes encoding enzymes involved in the degradation of 4HB is induced by both 4HBA and 4HB, as expected; however, overexpression of <i>pecM</i> attenuates the induction by 4HBA, suggesting that 4HBA is a substrate for PecM. Consistent with this inference, untargeted metabolomics shows that 4HBA accumulates intracellularly when <i>pecM</i> is disrupted. Analysis of PecS by thermal stability assay and DNase I footprinting suggests that 4HBA is not a ligand for PecS. Taken together, our data suggest that 4HBA is a substrate for PecM.IMPORTANCEPlant roots secrete a number of compounds that may be toxic to bacteria residing in the surrounding soil. One such bacterium is <i>Agrobacterium fabrum</i>, which infects plants and induces tumor formation. We show here that an <i>A. fabrum</i> strain in which the efflux pump PecM has been disrupted accumulates 4-hydroxybenzaldehyde, and that this plant root exudate induces the expression of <i>pecM</i>. Our data suggest that PecM and PecS, a transcription factor that regulates <i>pecM</i> expression, both function to promote <i>A. fabrum</i> fitness in the rhizosphere. As a competitive advantage in the rhizosphere is a prerequisite for subsequent plant infection, our data contribute to a more complete understanding of the <i>A. fabrum</i> infection process.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0015025"},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284479","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Deciphering the <i>Salmonella</i> T6SS toolkit: two decades of research decoding a versatile bacterial weapon.","authors":"Carlos J Blondel, Fernando A Amaya, Felipe Reyes-Méndez, Victoria Soriano-Mora, Carla Vargas, Ayleen Parra, María C Opazo, Viviana Toledo, María F Barros-Infante, Carlos A Santiviago, David Pezoa","doi":"10.1128/jb.00188-25","DOIUrl":"https://doi.org/10.1128/jb.00188-25","url":null,"abstract":"<p><p>The Type VI Secretion System (T6SS) is a critical fitness and virulence factor of many Gram-negative bacteria. Five T6SS gene clusters have been described in <i>Salmonella</i>, each one encoded within different pathogenicity islands (i.e., SPI-6, SPI-19, SPI-20, SPI-21, and SPI-22). The events of gain and loss of these T6SS gene clusters have contributed to shape the genome evolution of different <i>Salmonella</i> serotypes. In addition, the differential distribution of T6SS and the ever-increasing repertoire of predicted effector proteins is likely to play an important role in the environmental fitness and pathogenic potential of different <i>Salmonella</i> serotypes. This review summarizes the current knowledge on the role played by T6SS in <i>Salmonella</i> biology, highlighting the major milestones in the field over the past two decades. We discuss the expanding repertoire of T6SS effector proteins identified to date and examine the current understanding of mechanisms controlling T6SS expression in <i>Salmonella</i>, focusing on host-derived cues and regulators involved. Finally, we provide a critical analysis of conflicting reports and suggest future directions for the research in the field. A better understanding of these processes could expand our knowledge of <i>Salmonella</i> biology, and the mechanisms behind how this versatile secretion system enables <i>Salmonella</i> to thrive in competitive microbial environments and contribute to host colonization.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0018825"},"PeriodicalIF":2.7,"publicationDate":"2025-06-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144284477","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Functional consequences of genetic variations in DgoR, a GntR/FadR family transcriptional repressor of D-galactonate metabolism in <i>Escherichia coli</i>.","authors":"Swati Singh, Rajesh Mishra, Richa Ashok Kakkar, Shivam Singla, Akhil Pratap, Gaurav Sharma, Monika Sharma, Rachna Chaba","doi":"10.1128/jb.00103-25","DOIUrl":"https://doi.org/10.1128/jb.00103-25","url":null,"abstract":"<p><p>Genetic variations in transcriptional regulators (TRs) of metabolic loci can influence host-bacterial interactions by affecting carbon utilization. Although the metabolism of sugar acids, including D-galactonate, is extensively implicated in the colonization and virulence of enteric bacteria, there has been no investigation on the extent of variations in their pathway-specific TRs. DgoR, the TR of D-galactonate metabolism, is the best-characterized GntR/FadR family sugar acid TR in enteric bacteria, recognized by the presence of an N-terminal winged helix-turn-helix DNA-binding domain and a C-terminal effector-binding and oligomerization (E-O) domain connected by a linker. Here, we examined 340 <i>Escherichia coli</i> isolates for variations in <i>dgoR</i> and studied their effect on repressor function. Genetic and biochemical studies identified variants with a partial loss of DNA-binding ability (P24L and A152E) and a decreased response to D-galactonate (R71C and P92L). Because the linker residue R71C resulted in a reduced response to D-galactonate and the E-O domain residue A152E led to a DNA binding defect, we performed simulations to probe their altered allosteric behavior. We observed that the correlation patterns, dynamics, and networks of the variants are indeed distinct from the wild type. Importantly, corroborating their repressor function, R71C and A152E variations impacted the growth of natural isolates in D-galactonate. Alignment-based variation detection across all <i>E. coli</i> and Enterobacterales identical protein group data sets revealed less prevalence of these four variations. Collectively, the present study highlights the need for a thorough analysis of the effect of variations in sugar acid TRs on repressor function and their effect on host-bacterial interactions.IMPORTANCESugar acids are used as carbon sources by enteric bacteria, both commensals and pathogens, with numerous studies highlighting their importance in host-bacterial interactions. Here, taking <i>Escherichia coli</i> DgoR, the transcriptional regulator (TR) of D-galactonate metabolism, as a representative, we showed that genetic variations in sugar acid TRs can affect their function and impact the utilization of these carbon sources by natural isolates. As the ability to use limiting nutrients enables bacteria to compete with the complex microbial community of the host, our study emphasizes the need for a comprehensive analysis of variations in sugar acid TRs to determine whether they influence the competition. These studies can help envision approaches for promoting the growth of commensals to eliminate their pathogenic counterparts.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0010325"},"PeriodicalIF":2.7,"publicationDate":"2025-06-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144266309","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The DigH glycosyl hydrolase is conditionally required for daughter cell separation in <i>Escherichia coli</i>.","authors":"Joseph C Bryant, Emily J Robbs, Alongkorn Kurilung, Brittney A Dinkel, Intawat Nookaew, Matthew A Jorgenson","doi":"10.1128/jb.00068-25","DOIUrl":"https://doi.org/10.1128/jb.00068-25","url":null,"abstract":"<p><p>The peptidoglycan (PG) cell wall is a mesh-like layer that shapes bacteria and protects against osmotically induced lysis. PG is composed of glycan strands and peptide chains that link together to form a continuous layer that surrounds the cell. PG hydrolases are required for cell wall maturation, and many are employed during cell separation. During cell division, amidases remove peptides from the glycan backbone, and the resulting denuded glycans (dnGs) are degraded by lytic transglycosylases (LTs). The gram-negative bacterium <i>Escherichia coli</i> encodes eight functional LTs (<i>mltA-G</i> and <i>slt</i>) and one putative LT (<i>rlpA</i>), and a mutant strain lacking six (Δ<i>mltACDE</i>Δ<i>slt</i>Δ<i>rlpA</i>), which we refer to as ΔLT cells, accumulates dnGs and produces short chains of cells. A morphological suppressor of the ΔLT chaining defect was isolated, and deletion analysis indicated that suppression relied primarily on increased activity of DigH, a denuded-specific hydrolase that accumulates at the midcell during cell division. Further analyses revealed that DigH is critical for cell separation in ΔLT but not wild-type cells and that dnGs accumulate even more in ΔLT cells when DigH is absent. Thus, DigH is a denuded-specific hydrolase that is conditionally required for cell separation in <i>E. coli</i>. Altogether, our findings deepen our understanding of the specific cellular function of DigH and of PG maturation in <i>E. coli</i>.</p><p><strong>Importance: </strong>Most bacteria are surrounded by an essential polymer known as the peptidoglycan cell wall. During cell division, a transient form of peptidoglycan is generated between the developing daughter cells that must be cleaved so that cells can separate. Here, we show that the DigH hydrolase is conditionally required for cell separation when this transient cell wall structure accumulates in the gram-negative bacterium <i>Escherichia coli</i>. These findings deepen our understanding of how the peptidoglycan layer is remodeled during cell division.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0006825"},"PeriodicalIF":2.7,"publicationDate":"2025-06-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144258135","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"<i>Fusobacterium nucleatum</i>: strategies for adapting to aerobic stress.","authors":"Alexandra K McGregor, Kirsten R Wolthers","doi":"10.1128/jb.00090-25","DOIUrl":"https://doi.org/10.1128/jb.00090-25","url":null,"abstract":"<p><p><i>Fusobacterium nucleatum</i>-a gram-negative anaerobe-is commensal to the oral cavity, where it plays an important role in the maturation of the oral biofilm. The bacterium is also an opportunistic pathogen, given its association with systemic infections and cancer progression. Although residing in largely anoxic microenvironments within the oral biofilm, <i>F. nucleatum</i> encounters oxygen (O₂) present in the circulating saliva and reactive oxygen species formed endogenously, by an activated immune system or neighboring oral commensal streptococci. This review explores the bacterium's adaptive mechanisms that enable survival under oxidative stress. We discuss how <i>F. nucleatum</i> mitigates oxidative damage and aerobic stress through common detoxifying and repair enzymes such as peroxiredoxins, methionine sulfoxide reductases, and rubrerythrin and through the activity of the recently identified multicomponent enzyme, termed butyryl-CoA oxygen oxidoreductase. Turnover by the latter enzyme enables <i>F. nucleatum</i> to exploit molecular oxygen for the conservation of energy. Additionally, we discuss how a two-component signal transduction system, ModRS, a global regulator of oxidative stress, functions in part to reprogram core metabolism to counterbalance the inactivation of a glycyl radical enzyme hypersensitive to O₂. Our findings provide new insight into how <i>F. nucleatum</i> resists fluctuating dioxygen environments, shedding light on its persistence in extraoral sites and its potential role in disease progression.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0009025"},"PeriodicalIF":2.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234198","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Applying the brakes to transcription: regulation of gene expression by RNA polymerase pausing.","authors":"Oshadhi T Jayasinghe, Paul Babitzke","doi":"10.1128/jb.00084-25","DOIUrl":"https://doi.org/10.1128/jb.00084-25","url":null,"abstract":"<p><p>Transcription by RNA polymerase is punctuated by transient pausing events. Pausing provides additional time for proper RNA folding and binding of regulatory factors to the paused transcription elongation complex or the nascent RNA. Depending on the organism and the genomic context, the general transcription elongation factors NusA and NusG stimulate or suppress pausing. Both <i>Escherichia coli</i> and <i>Bacillus subtilis</i> NusA stimulate pausing <i>in vitro</i>, while the genome-wide role of NusA on pausing has only been examined in <i>B. subtilis</i>. NusG-dependent pausing was identified throughout the <i>B. subtilis</i> genome, and in several instances, these pauses were shown to regulate the expression of the downstream gene(s). This pro-pausing activity was also observed for <i>Mycobacterium tuberculosis</i> NusG. In contrast, <i>E. coli</i> NusG functions as an anti-pausing factor by suppressing pausing throughout the genome. These differences in the function of NusG highlight the importance of studying fundamental processes in a variety of bacterial species. This review will highlight recent advances gained by the ability to identify pauses genome-wide that are either stimulated or suppressed by these two conserved transcription elongation factors.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0008425"},"PeriodicalIF":2.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Identification of electron transfer enzymes in <i>Thermoanaerobacterium saccharolyticum</i>.","authors":"João H T M Fabri, Layse C de Souza, Luana W Bergamo, Lee R Lynd, Daniel G Olson","doi":"10.1128/jb.00107-25","DOIUrl":"https://doi.org/10.1128/jb.00107-25","url":null,"abstract":"<p><p><i>Thermoanaerobacterium saccharolyticum</i> is a promising candidate for the production of biofuels from lignocellulosic sugars; however, the genes associated with electron transfer from ferredoxin are poorly characterized. In this work, we deleted several key electron transfer genes. We showed that the <i>tsac_1705</i> gene is not necessary for high-yield ethanol production, but that a set of four other genes (<i>nfnA</i>, <i>nfnB</i>, <i>hfsD</i>, and <i>hydA</i>) are necessary. We showed that the <i>nfnB</i> gene can function as a monofunctional (i.e., non-bifurcating) FNOR enzyme in the absence of <i>nfnA</i>. The phenotypes of the <i>hfsD</i>, <i>hydA</i>, and <i>hfsD hydA</i> double-deletion strains are consistent with their function via hydrogen cycling.</p><p><strong>Importance: </strong>The improved understanding of electron transfer pathways in <i>T. saccharolyticum</i> will enable future efforts to transfer the robust ethanol production pathway from this microbe to other organisms, with potential implications for industrial biofuel production.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0010725"},"PeriodicalIF":2.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Lon-dependent proteolysis in oxidative stress responses.","authors":"Kubra Yigit, Peter Chien","doi":"10.1128/jb.00005-25","DOIUrl":"https://doi.org/10.1128/jb.00005-25","url":null,"abstract":"<p><p>Accumulation of reactive oxygen species (ROS) induces oxidative stress, leading to substantial damage to cellular macromolecules, necessitating efficient protein quality control mechanisms. The Lon protease, a highly conserved ATP-dependent protease, is thought to play a central role in mitigating oxidative stress by targeting damaged and misfolded proteins for degradation. This review examines the role of Lon in oxidative stress responses, including its role in degrading oxidized proteins, regulating antioxidant pathways, and modulating heme and Fe-S cluster homeostasis. We highlight cases of substrate recognition through structural changes and describe situations where Lon activity is further regulated by redox conditions. By synthesizing studies across a range of organisms, we find that despite the clear importance of Lon for oxidative stress tolerance, universal rules for Lon degradation of damaged proteins during this response remain unclear.</p>","PeriodicalId":15107,"journal":{"name":"Journal of Bacteriology","volume":" ","pages":"e0000525"},"PeriodicalIF":2.7,"publicationDate":"2025-06-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144234201","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}