microLife最新文献_第6页

Editorial: society journals matter-supporting science through renewed commitment. 社论：社会期刊通过更新的承诺支持科学。

microLife Pub Date : 2025-11-19 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf032

Paul B Rainey, Puri López-García, Zeynep Ceren Karahan, Paul Williams, Stipan Jonjić, Kenneth N Timmis

引用次数: 0

Functional diversity and molecular interactions of small membrane proteins in bacteria. 细菌小膜蛋白的功能多样性和分子相互作用。

microLife Pub Date : 2025-11-07 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf035

Jing Yuan, Hans-Georg Koch, Bork A Berghoff

引用次数: 0

One transcript, two functions: the emerging roles of dual-function RNAs. 一个转录本，两种功能：双功能rna的新角色。

microLife Pub Date : 2025-10-23 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf034

Liz Maria Luke, Kai Papenfort

引用次数: 0

Evolutionary insights into provirus-encoded CRISPR-Cas systems in halophilic archaea. 嗜盐古菌中原病毒编码的CRISPR-Cas系统的进化见解。

microLife Pub Date : 2025-10-22 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf033

Doron Naki, Uri Gophna

{"title":"Evolutionary insights into provirus-encoded CRISPR-Cas systems in halophilic archaea.","authors":"Doron Naki, Uri Gophna","doi":"10.1093/femsml/uqaf033","DOIUrl":"10.1093/femsml/uqaf033","url":null,"abstract":"Prokaryotic microorganisms coexist with mobile genetic elements (MGEs), which can be both genetic threats and evolutionary catalysts. In Haloferax lucentense, a halophilic archaeon, we have recently identified an unusual genomic arrangement: a complete type I-B CRISPR-Cas system encoded on a megaplasmid and an incomplete type I-B system within an integrated provirus in the main chromosome. The provirus-encoded system lacks the adaptation genes (cas1, cas2, and cas4), suggesting its potential reliance on the megaplasmid-encoded CRISPR-Cas module for the acquisition of new spacers. This arrangement suggests a potential instance of \"adaptive outsourcing,\" where a provirus might leverage a co-resident MGE for a key function. Through comparative genomics, we show that similar proviral CRISPR-Cas systems are found in distantly related haloarchaea (e.g. Natrinema and Halobacterium), indicating probable virus-mediated horizontal transfer and suggesting they may function as mobile defense modules. Phylogenetic analysis highlights distinct evolutionary origins of the two systems: the plasmid system clusters with other Haloferax CRISPR-Cas systems, while the proviral system clusters with those from other genera, consistent with horizontal acquisition. Interestingly, spacer analysis reveals that the proviral systems predominantly target viral sequences, while the plasmid system appears to target both plasmids and viral sequences, a distribution mirroring broader trends observed in other plasmid- and chromosome-encoded CRISPR systems. This observed targeting preference suggests a potential for complementarity that could support a model of cooperative immunity, where each system may protect its genetic \"owner\" from competition and, indirectly, the host.","PeriodicalId":74189,"journal":{"name":"microLife","volume":"6 ","pages":"uqaf033"},"PeriodicalIF":0.0,"publicationDate":"2025-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12596717/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145490960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Correction to: Avirulent Pseudomonas aeruginosa T3SS-negative strains belonging to Clade 5 produce variable quantities of secondary metabolites. 更正：无毒的铜绿假单胞菌t3ss阴性菌株属于进化枝5，产生可变数量的次生代谢物。

microLife Pub Date : 2025-10-13 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf031

引用次数: 0

Storm over science: predatory practices and the fight for research reliability. 科学风暴：掠夺性行为和对研究可靠性的争夺。

microLife Pub Date : 2025-10-11 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf029

Víctor de Lorenzo, Paul B Rainey, Paul Williams, Zeynep Ceren Karahan, Puri López-García, Stipan Jonjić, Kenneth N Timmis

引用次数: 0

The small bacterial membrane protein YohP induces nucleoid condensation in E. coli and inhibits oligomerization of antimicrobial peptides. 小细菌膜蛋白YohP在大肠杆菌中诱导类核凝聚并抑制抗菌肽的寡聚化。

microLife Pub Date : 2025-10-08 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf030

Ana Natriashvili, Nahid Mohammadsadeghi, Eva Smudde, Bork Berghoff, Maximilian H Ulbrich, Hans-Georg Koch

{"title":"The small bacterial membrane protein YohP induces nucleoid condensation in E. coli and inhibits oligomerization of antimicrobial peptides.","authors":"Ana Natriashvili, Nahid Mohammadsadeghi, Eva Smudde, Bork Berghoff, Maximilian H Ulbrich, Hans-Georg Koch","doi":"10.1093/femsml/uqaf030","DOIUrl":"10.1093/femsml/uqaf030","url":null,"abstract":"Prokaryotic organisms execute multiple stress response mechanisms in order to cope with rapidly changing environments. Some mechanisms respond to specific cues, such as the OxyR-dependent response to hydrogen peroxide or the SOS-response that is induced upon DNA-damage. These specific responses complement general mechanisms that respond to multiple and diverse stressors. One example is nucleoid condensation, which is a rapid and effective mechanism for genome protection and observed in response to various stresses, including entry into stationary phase. Recently, the upregulation of small membrane proteins (SMPs) in response to stress was observed, but details on how this emerging class of proteins modulate the stress response is largely unknown. Here, we demonstrate that the production of two SMPs, YohP and YncL, cause nucleoid condensation in Escherichia coli. Nucleoid condensation is the result of YohP-/YncL-induced sublethal membrane depolarization, which induces the phage-shock response and leads to a reduction of global protein synthesis. YohP production also prevents the oligomerization of the antimicrobial peptide magainin-2 in the E. coli membrane and reduces the metabolic activity of E. coli cells. Thus, the synthesis of YohP and likely of other SMPs potentially protects bacterial cells against some unfavorable conditions by shifting them into a metabolically silent state.","PeriodicalId":74189,"journal":{"name":"microLife","volume":"6 ","pages":"uqaf030"},"PeriodicalIF":0.0,"publicationDate":"2025-10-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12542507/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145357085","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Single nucleotide switches confer bacteriophage resistance to Pseudomonas protegens. 单核苷酸开关赋予噬菌体对假单胞菌蛋白的抗性。

microLife Pub Date : 2025-10-06 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf028

Jordan Vacheron, Clara M Heiman, Daniel Garrido-Sanz, Martine Caroff, Maryam Darabi, Christoph Keel

引用次数: 0

Functional and intricate interaction network connecting Helicobacter pylori Cag type 4 secretion system surface proteins with outer membrane proteins HopQ and HopZ. 连接幽门螺杆菌Cag 4型分泌系统表面蛋白与外膜蛋白HopQ和HopZ的功能和复杂的相互作用网络。

microLife Pub Date : 2025-10-06 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf027

Felix Metz, Johanna Beilmann, Simon H Bats, Andreas Latoscha, Gregor Witte, Remco T A Megens, Karl-Peter Hopfner, Kaisa Thorell, Wolfgang Fischer, Laurent Terradot, Sebastian Suerbaum, Christine Josenhans

{"title":"Functional and intricate interaction network connecting Helicobacter pylori Cag type 4 secretion system surface proteins with outer membrane proteins HopQ and HopZ.","authors":"Felix Metz, Johanna Beilmann, Simon H Bats, Andreas Latoscha, Gregor Witte, Remco T A Megens, Karl-Peter Hopfner, Kaisa Thorell, Wolfgang Fischer, Laurent Terradot, Sebastian Suerbaum, Christine Josenhans","doi":"10.1093/femsml/uqaf027","DOIUrl":"10.1093/femsml/uqaf027","url":null,"abstract":"The Helicobacter pylori cag pathogenicity island (cagPAI) encodes a complex virulence-associated type IV secretion system (CagT4SS). Recently, structural detail on the CagT4SS has been substantially improved by Cryo-EM. However, important structural and functional information is still missing. In the present study, we followed the hypothesis that H. pylori T4SS external proteins may form a surface-exposed assembly, together with non-CagT4SS proteins, which may be essential for T4SS function. Using interaction screens followed by biochemical and functional characterization, we have enhanced the knowledge about functional protein-protein interactions of the CagT4SS extracellular proteins. This comprises newly identified interactions of CagT4SS surface proteins, including the VirB2 homolog CagC, the VirB5 homolog CagL and CagN, with outer membrane proteins HopQ and HopZ. We have further quantitated direct, pH dependent, interactions of T4SS surface proteins with HopZ and HopQ, with host cell factors CEACAM and integrin, and self-interactions of both HopZ and HopQ. Utilizing chromosomal tag insertions in H. pylori, we detected surface-exposed colocalization of HopQ with T4SS components in the absence or, for HopQ, also in the presence of human gastric epithelial cells. Functionally antagonistic roles of HopQ and HopZ were uncovered in early proinflammatory human epithelial cell activation by the T4SS. In summary, we identified a network of interactions between H. pylori outer membrane proteins and CagT4SS surface proteins that are functionally relevant for T4SS-dependent transport processes. This study provides a valuable resource guiding future studies to refine structure and mechanistic roles of the surface-exposed portions of the CagT4SS.","PeriodicalId":74189,"journal":{"name":"microLife","volume":"6 ","pages":"uqaf027"},"PeriodicalIF":0.0,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12542503/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145357051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Functional insights into Solo-Cas4 in Methanosarcina mazei Gö1. Solo-Cas4在Methanosarcina mazei Gö1中的功能研究。

microLife Pub Date : 2025-10-03 eCollection Date: 2025-01-01 DOI: 10.1093/femsml/uqaf024

Luise Rentz, Lisa Hellwig, Sabine Schneider, Ruth A Schmitz

{"title":"Functional insights into Solo-Cas4 in Methanosarcina mazei Gö1.","authors":"Luise Rentz, Lisa Hellwig, Sabine Schneider, Ruth A Schmitz","doi":"10.1093/femsml/uqaf024","DOIUrl":"10.1093/femsml/uqaf024","url":null,"abstract":"Solo-Cas4 homologs are Cas4-family proteins found outside of canonical CRISPR-Cas operons. Here, we present the biochemical characterization of Solo-Cas4 from Methanosarcina mazei Gö1. We found significantly upregulated solo-cas4 transcript levels during stationary phase, while remaining constant under oxygen exposure, temperature shifts, high salt conditions or virus challenge. Heterologously expressed as a SUMO-fusion, the purified tag-free protein displays an absorption peak at 420 nm, indicative of a [4Fe-4S]-cluster. Size-exclusion-chromatography revealed that Solo-Cas4 forms a higher oligomeric complex, with an apparent molecular mass of 318 kDa. In vitro nuclease activity assays demonstrated that Solo-Cas4 cleaves metal-dependent linear dsDNA, with highest cleavage activity in the presence of Mn2+, followed by Mg2+, while Ca²⁺ and Cu²⁺ result in negligible cleavage. Isoleucine169 was identified to be crucial for catalysis, mutating it to alanine completely abolished nuclease activity. Mutating any of the four conserved cysteines-proposed to coordinate the [4Fe-4S]-cluster did not affect nuclease activity; however, it abolishes metal cluster binding. Supercoiled circular dsDNA was preferentially nicked by Solo-Cas4 in the presence of Mg2+, whereas Mn2+ also led to linearization followed by complete degradation. Besides, ssDNA was cleaved by Solo-Cas4 but with lower activity. In agreement, Microscale thermophoresis analysis revealed strong dsDNA binding with highest affinity to supercoiled circular DNA, and weak ssDNA binding. Overall, these findings indicate that M. mazei Solo-Cas4 is a high oligomeric Cas4-family nuclease that preferentially targets supercoiled dsDNA and is upregulated during stationary growth.","PeriodicalId":74189,"journal":{"name":"microLife","volume":"6 ","pages":"uqaf024"},"PeriodicalIF":0.0,"publicationDate":"2025-10-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12501428/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145253816","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0