Molecular Microbiology最新文献

{"title":"The Complex and Challenging World of the Host–Pathogen Interaction","authors":"Marcel I. Ramirez","doi":"10.1111/mmi.15310","DOIUrl":"https://doi.org/10.1111/mmi.15310","url":null,"abstract":"","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"6 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142697063","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative Multi-Omics Survey Reveals Novel Specialized Metabolites and Biosynthetic Gene Clusters Under GacS Control in Pseudomonas donghuensis Strain SVBP6","authors":"Federico Matías Muzio, Corri D. Hamilton, Paolo Stincone, Betina Agaras, Cara H. Haney, Daniel Petras, Claudio Valverde","doi":"10.1111/mmi.15329","DOIUrl":"https://doi.org/10.1111/mmi.15329","url":null,"abstract":"In <i>Pseudomonas donghuensis</i> SVBP6, isolated from an agricultural field, the well-conserved Gac-Rsm pathway upregulates biosynthesis of the antifungal compound 7-hydroxytropolone (7-HT). However, 7-HT does not fully explain the strain's Gac-Rsm-dependent antimicrobial activity. Here, we combined comparative transcriptomic, proteomic, and metabolomic approaches to identify novel GacS-dependent biosynthetic gene clusters (BGC) and/or extracellular specialized metabolites. Our data revealed a broad impact of GacS on gene expression and extracellular metabolite profile of SVBP6. At both the mRNA and polypeptide levels, specialized metabolism was the main affected functional category in the <i>gacS</i> mutant. The major extracellular MS/MS spectral families promoted by GacS were fatty acid amides, fatty acids, and alkaloids. GacS was required for the production of the antimicrobial compound pseudoiodinine and to activate expression of the corresponding BGC. We also detected GacS-dependent production of 2,3,4-trihydro-β-carboline-1-one, which may add to the antimicrobial arsenal of SVBP6. Furthermore, transcriptomics and proteomics pinpointed several GacS-activated BGCs that had escaped <i>in silico</i> genome mining tools. Altogether, comparative multi-omics analyses of <i>gacS</i> loss-of-function mutants in <i>Pseudomonas</i> isolates are a promising strategy to uncover bioactive metabolites and/or their BGCs. Discovery of novel natural products is important for harnessing the potential of microbiota to improve crop plant growth and health.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"16 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637584","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Bacterial Organelles in Iron Physiology","authors":"Kristina M. Ferrara, Kuldeepkumar R. Gupta, Hualiang Pi","doi":"10.1111/mmi.15330","DOIUrl":"https://doi.org/10.1111/mmi.15330","url":null,"abstract":"Bacteria were once thought to be simple organisms, lacking the membrane-bound organelles found in eukaryotic cells. However, recent advancements in microscopy have changed this view, revealing a diverse array of organelles within bacterial cells. These organelles, surrounded by lipid bilayers, protein-lipid monolayers, or proteinaceous shells, play crucial roles in facilitating biochemical reactions and protecting cells from harmful byproducts. Unlike eukaryotic organelles, which are universally present, bacterial organelles are species-specific and induced only under certain conditions. This review focuses on the bacterial organelles that contain iron, an essential micronutrient for all life forms but potentially toxic when present in excess. To date, three types of iron-related bacterial organelles have been identified: two membrane-bound organelles, magnetosomes and ferrosomes, and one protein-enclosed organelle, the encapsulated ferritin-like proteins. This article provides an updated overview of the genetics, biogenesis, and physiological functions of these organelles. Furthermore, we discuss how bacteria utilize these specialized structures to adapt, grow, and survive under various environmental conditions.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"9 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142637585","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Converging Roles of the Metal Transporter SMF11 and the Ferric Reductase FRE1 in Iron Homeostasis of Candida albicans","authors":"Naisargi K. Patel, Marika S. David, Shuyi Yang, Ritu Garg, Hongyu Zhao, Brendan P. Cormack, Valeria C. Culotta","doi":"10.1111/mmi.15326","DOIUrl":"https://doi.org/10.1111/mmi.15326","url":null,"abstract":"Pathogenic fungi must appropriately sense the host availability of essential metals such as Fe. In <i>Candida albicans</i> and other yeasts, sensing of Fe involves mitochondrial Fe-S clusters. Yeast mutants for Fe-S cluster assembly sense Fe limitation even when Fe is abundant and hyperaccumulate Fe. We observe this same disrupted Fe sensing with <i>C. albicans</i> mutants of SMF11, a NRAMP transporter of divalent metals. Mutants of <i>smf11</i> hyperaccumulate both Mn and Fe and the elevated Mn is secondary to Fe overload. As with Fe-S biogenesis mutants, <i>smf11∆/∆</i> mutants show upregulation of ferric reductases that are normally repressed under high Fe, and Fe import is activated. However, unlike Fe-S biogenesis mutants, <i>smf11∆/∆</i> mutants show no defects in mitochondrial Fe-S enzymes. Intriguingly, this exact condition of disrupted Fe sensing without inhibiting Fe-S clusters occurs with <i>C. albicans fre1∆/∆</i> mutants encoding a ferric reductase. Mutants of <i>fre1</i> and <i>smf11</i> display similar perturbations in the cell wall, in filamentation and in the ROS burst of morphogenesis, a Fe-dependent process. As with FRE1, SMF11 is important for virulence in a mouse model for disseminated candidiasis. We propose a model in which FRE1 and SMF11 operate outside the mitochondrial Fe-S pathway to donate ferrous Fe for Fe sensing.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"2 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2024-11-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142599927","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Genetic analysis of translation initiation in bacteria: An initiator tRNA-centric view.","authors":"Kuldeep Lahry, Madhurima Datta, Umesh Varshney","doi":"10.1111/mmi.15243","DOIUrl":"10.1111/mmi.15243","url":null,"abstract":"<p><p>Translation of messenger RNA (mRNA) in bacteria occurs in the steps of initiation, elongation, termination, and ribosome recycling. The initiation step comprises multiple stages and uses a special transfer RNA (tRNA) called initiator tRNA (i-tRNA), which is first aminoacylated and then formylated using methionine and N¹⁰-formyl-tetrahydrofolate (N¹⁰-fTHF), respectively. Both methionine and N¹⁰-fTHF are produced via one-carbon metabolism, linking translation initiation with active cellular metabolism. The fidelity of i-tRNA binding to the ribosomal peptidyl-site (P-site) is attributed to the structural features in its acceptor stem, and the highly conserved three consecutive G-C base pairs (3GC pairs) in the anticodon stem. The acceptor stem region is important in formylation of the amino acid attached to i-tRNA and in its initial binding to the P-site. And, the 3GC pairs are crucial in transiting the i-tRNA through various stages of initiation. We utilized the feature of 3GC pairs to investigate the nuanced layers of scrutiny that ensure fidelity of translation initiation through i-tRNA abundance and its interactions with the components of the translation apparatus. We discuss the importance of i-tRNA in the final stages of ribosome maturation, as also the roles of the Shine-Dalgarno sequence, ribosome heterogeneity, initiation factors, ribosome recycling factor, and coevolution of the translation apparatus in orchestrating a delicate balance between the fidelity of initiation and/or its leakiness to generate proteome plasticity in cells to confer growth fitness advantages in response to the dynamic nutritional states.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"772-788"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139972680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"In Vivo Cross-Linking Sheds Light on the Salmonella Divisome in Which PBP3 and PBP3_SAL Compete for Occupancy.","authors":"Sónia Castanheira, David López-Escarpa, Alberto Paradela, Francisco García-Del Portillo","doi":"10.1111/mmi.15309","DOIUrl":"10.1111/mmi.15309","url":null,"abstract":"<p><p>Bacterial cell division is orchestrated by proteins that assemble in dynamic complexes collectively known as the divisome. Essential monofunctional enzymes with glycosyltransferase or transpeptidase (TPase) activities, FtsW and FtsI respectively, engage in the synthesis of septal peptidoglycan (sPG). Enigmatically, Salmonella has two TPases that can promote cell division independently: FtsI (PBP3) and the pathogen-specific paralogue PBP3_SAL. How Salmonella regulates the assembly of the sPG synthase complex with these two TPases, is unknown. Here, we characterized Salmonella division complexes in wild-type cells and isogenic mutants lacking PBP3 or PBP3_SAL. The complexes were cross-linked in vivo and pulled down with antibodies recognizing each enzyme. Proteomics of the immunoprecipitates showed that PBP3 and PBP3_SAL do not extensively cross-link in wild type cells, supporting the presence of independent complexes. More than 40 proteins cross-link in complexes in which these two TPases are present. Those identified with high scores include FtsA, FtsK, FtsQLB, FtsW, PBP1B, SPOR domain-containing proteins (FtsN, DedD, RlpA, DamX), amidase activators (FtsX, EnvC, NlpD) and Tol-Pal proteins. Other cross-linked proteins are the protease Prc, the elongasome TPase PBP2 and, D,D-endo- and D,D-carboxypeptidases. PBP3 and PBP3_SAL localize at midcell and compete for occupying the division complex in response to environmental cues. Thus, a catalytic-dead PBP3_SAL-S300A variant impairs cell division in a high osmolarity and acidic condition in which it is produced at levels exceeding those of PBP3. Salmonella may therefore exploit an 'adjustable' divisome to exchange TPases for ensuring cell division in distinct environments and, in this manner, expand its colonization capacities.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"797-818"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11586514/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142133258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Leptospira Leptolysin Contributes to Serum Resistance but Is Not Essential for Acute Infection.","authors":"Daniella Dos Santos Courrol, Cassia Moreira Santos, Rosa Maria Chura-Chambi, Lígia Morganti, Kátia Eliane Santos Avelar, Fernanda de Moraes Maia, Rodrigo Nunes Rodrigues-da-Silva, Elsio Augusto Wunder, Angela Silva Barbosa","doi":"10.1111/mmi.15327","DOIUrl":"10.1111/mmi.15327","url":null,"abstract":"<p><p>Previous in vitro works focusing on virulence determinants of the spirochete Leptospira implicated metalloproteinases as putative contributing factors to the pathogenicity of these bacteria. Those proteins have the capacity to degrade extracellular matrix components (ECM) and proteins of host's innate immunity, notably effectors of the complement system. In this study, we gained further knowledge on the role of leptolysin, one of the leptospiral-secreted metalloproteinases, previously described as having a broad substrate specificity. We demonstrated that a proportion of human patients with mild leptospirosis evaluated in the current study produced antibodies that recognize leptolysin, thus indicating that the protease is expressed during host infection. Using recombinant protein and a knockout mutant strain, Manilae leptolysin^-, we determined that leptolysin contributes to Leptospira interrogans serum resistance in vitro, likely by proteolysis of complement molecules of the alternative, the classical, the lectin, and the terminal pathways. Furthermore, in a hamster model of infection, the mutant strain retained virulence; however, infected animals had lower bacterial loads in their kidneys. Further studies are necessary to better understand the role and potential redundancy of metalloproteinases on the pathogenicity of this important neglected disease.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"720-729"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142558294","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Detection of 2-ethyl-1-hexanol and its modulating effect in biofilm of Fusarium oxysporum.","authors":"Flavia Franco Veiga, Emilli Karine Marcomini, Alana Salvador, Lucas Ulisses Rovigatti Chiavelli, Isabella Letícia Esteves Barros, Lidiane Vizioli de Castro, Diego Luis Lucca, Larissa Miwa Kikuchi Ochikubo, Mauro Luciano Baesso, Armando Mateus Pomini, Terezinha Inez Estivalet Svidzinski, Melyssa Negri","doi":"10.1111/mmi.15194","DOIUrl":"10.1111/mmi.15194","url":null,"abstract":"<p><p>In immunocompetent individuals, Fusarium spp. stands out as the causative agent of onychomycosis, among the non-dermatophyte molds. Despite evidence indicating that Fusarium oxysporum organizes itself in the form of a biofilm causing onychomycosis, there is little literature on the etiopathogenesis of the biofilm on the nail, specifically the signaling molecules present, known as quorum sensing (QS). Thus, this study detected the presence of a molecule related to QS from the ex vivo biofilm of F. oxysporum on human nail and investigated its effect on preformed biofilm in vitro. The detection and physicochemical characterization of a QS molecule, from the extracellular matrix (ECM), was carried out by Fourier transform infrared (FTIR) spectroscopy with an attenuated total reflectance (ATR) accessory and by headspace gas chromatography coupled to mass spectrometry (GC-MS) analyses. Determination of viable cells, cell activity, total biomass, ECM components and scanning electron microscopy (SEM) were performed to evaluate the influence of the QS molecule on the in vitro biofilm of F. oxysporum. The beginning, in the ex vivo biofilm of F. oxysporum on human nails, the volatile organic compound 2-ethyl-1-hexanol (2EH) was detected as a component of QS. Thereafter in vitro analyses, synthetic 2EH was able to modulate the biofilm by stimulating its filament, increasing total biomass and ECM production in terms of total carbohydrates, but with a reduction in total proteins and nucleic acids. We thus evidence, for the first time, the presence of 2EH in the biofilm of F. oxysporum, developed on the human nail, and the in vitro action of this compound as a QS molecule.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"630-642"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138461149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effect of nutritional and oxidative stress on the metabolome of Trypanosoma cruzi.","authors":"Michel Augusto Silva, Mario Augusto Izidoro, Mirella Aricó, Luiz Juliano, Sergio Schenkman","doi":"10.1111/mmi.15279","DOIUrl":"10.1111/mmi.15279","url":null,"abstract":"<p><p>Trypanosoma cruzi, a flagellated protozoan, is the causative agent of Chagas disease. The parasite has developed various mechanisms to get through its intricate life cycle and adapt to different evolutionary phases. T. cruzi proliferates in the insect vector's digestive tract as an epimastigote form, encountering fluctuating nutrient availability and oxidative stress caused by the digestion of red blood cells from the mammalian host blood meal. To unravel how the parasite's metabolism adapts to these changing conditions, we conducted an analysis of the chemical species present in epimastigote forms. This involved comparing cultured parasites with those subjected to nutritional deficiency or oxidative stress using untargeted metabolomics. We looked at 21 samples: seven biological copies of parasites that were actively growing, seven samples that were put in a medium without nutrients for 3 h, and seven samples that were treated with glucose oxidase for 30 min to make H₂O₂ continuously. Importantly, in all conditions, parasite viability was maintained when the samples were collected. Upon nutrient removal, we observed a substantial decrease in amino acids and carbohydrate metabolites, accompanied by the accumulation of fatty acids and steroids, with the predominance of inositol and sphingolipid metabolism, along with a simultaneous decrease in the levels of H₂O₂. In the presence of H₂O₂, a significant rise in components of the pentose pathway and specific amino acids such as methionine and serine occurred, along with pathways related to an increase in antioxidant species metabolism such as ribulose 5-phosphate and glyceric acid. Conversely, fatty acid and steroid levels decrease. We found no common increase in metabolites or lipids. In contrast, eight species (succinic acid, glutamic acid, valine, 2-hydroxyisocaproic acid, alanine, indolelactic acid, proline, and lanosterol) were consumed under both stresses. These findings underscore the rapid and distinct enrichment responses in amino acids, lipids, and carbohydrates required to cope with each different environmental condition. We concluded that T. cruzi presents a flexible metabolism that rapidly adapts to variable changes in the environment.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"704-719"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141176173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The host Rab9a/Rab32 axis is actively recruited to the Trypanosoma cruzi parasitophorous vacuole and benefits the infection cycle.","authors":"Betiana Nebaí Salassa, Juan Agustín Cueto, María Cristina Vanrell, María Belén López, Albert Descoteaux, Carlos Alberto Labriola, Patricia Silvia Romano","doi":"10.1111/mmi.15217","DOIUrl":"10.1111/mmi.15217","url":null,"abstract":"<p><p>Trypanosoma cruzi, the etiological agent of Chagas disease is a protozoan parasite that infects phagocytic and non-phagocytic mammalian cells. At early stages of infection, trypomastigotes, the infective forms of this parasite, localize in a vesicular compartment called the T. cruzi parasitophorous vacuole until the exit of parasites to the host cell cytoplasm where continue their infective cycle. Rab proteins participate in the membrane traffic's molecular machinery, functioning as central regulators of vesicle recognition and transport. In previous work, we demonstrated that endocytic Rabs are key factors of the T. cruzi infection process in non-phagocytic cells, regulating the formation and the maturation of the vacuole. In this work, we identified and characterized other molecular components of the vesicular transport pathways and their participation in the T. cruzi infection. We found that Rab9a and Rab32, two regulators of the endocytic and autophagic pathways, were actively recruited to the T. cruzi vacuoles and favored the late stages of the infective process. The recruitment was specific and dependent on T. cruzi protein synthesis. Interestingly, Rab32 association depends on the presence of Rab9a in the vacuolar membrane, while the inhibition of the cysteine-protease cruzipain, a T. cruzi virulence factor, significantly decreases both Rab9a and Rab32 association with the vacuole. In summary, this work showed for the first time that specific molecules produced and secreted by the parasite can subvert intracellular components of host cells to benefit the infection. These new data shed light on the complex map of interactions between T. cruzi and the host cell and introduce concepts that can be useful in finding new forms of intervention against this parasite in the future.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":"643-659"},"PeriodicalIF":2.6,"publicationDate":"2024-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139403717","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}