Kehinde O Adebiyi, Laura C Lastra, Jane H Joncha, Sadie B Ruesewald, Stephen C Jacobson, Daniel B Kearns
{"title":"Topological, Functional, and Phylogenetic Analysis of the Cell Division Site Selection Protein MinJ of Bacillus subtilis.","authors":"Kehinde O Adebiyi, Laura C Lastra, Jane H Joncha, Sadie B Ruesewald, Stephen C Jacobson, Daniel B Kearns","doi":"10.1111/mmi.70119","DOIUrl":"https://doi.org/10.1111/mmi.70119","url":null,"abstract":"<p><p>The Min system disassembles FtsZ-rings after septation in Bacillus subtilis and is localized to the nascent division plane and cell poles by the protein MinJ. The N-terminal region of MinJ contains transmembrane segments while the C-terminal region contains a PDZ domain, but its membrane topology and functional domains are poorly understood. Here, we empirically tested competing topology models and found that MinJ is a nine-pass transmembrane protein with an extracellular N terminus and a cytoplasmic C terminal PDZ domain. Deletion of the PDZ domain resembled a MinJ null mutation but retained polar localization and interaction with both MinD and DivIVA. Deletion of transmembrane segments 6 and 7 abolished polar localization and interaction with MinD and DivIVA but conferred a hyper-minicell phenotype that was additive in the absence of MinD. Structural prediction by AlphaFold3 suggests that segments 6 and 7 may constitute an unusual transmembrane β-sheet, making MinJ perhaps the first of its kind to have such a secondary structure in the plasma membrane. Finally, phylogenetic analyses and structural comparison showed that MinJ sequence and structure are highly conserved within the Firmicutes and tightly co-conserved with MinD and DivIVA with which it interacts. Our work clarifies the membrane topology and functional organization of MinJ and supports models in which MinJ contributes to bacterial cell division through mechanisms beyond canonical Min system regulation.</p>","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":" ","pages":""},"PeriodicalIF":3.1,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149166650","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":"Nutrient Sensing and Growth Control in Plasmodium : Beyond mTOR Signaling","authors":"Felix Müller, Gabriele Pradel","doi":"10.1111/mmi.70123","DOIUrl":"https://doi.org/10.1111/mmi.70123","url":null,"abstract":"The mechanistic target of rapamycin (mTOR) signaling pathway is a central regulator of nutrient sensing, metabolism, growth, and stress adaptation in most eukaryotes. Malaria parasites of the genus <jats:italic>Plasmodium</jats:italic> , however, lack identifiable orthologues of mTOR kinase and its associated signaling complexes, raising the question of how these organisms coordinate environmental sensing with developmental progression and proliferation. Here, we discuss emerging evidence suggesting that <jats:italic>Plasmodium</jats:italic> has evolutionarily replaced the canonical mTOR signaling axis with a distributed regulatory architecture composed of parasite‐specific nutrient sensors, kinase‐based signaling pathways, translational repression mechanisms, and unconventional autophagy processes. Components such as KIN, PI3K, eIF2α kinases, eIF4E‐interacting protein DOZI, and Maf1 collectively preserve many hallmark outputs of mTOR signaling, including metabolic adaptation, stress tolerance, developmental plasticity, and reversible quiescence. In addition, malaria parasites interact with host mTOR pathways during infection, potentially exploiting host‐derived anabolic signaling environments to support intracellular development. These findings suggest that <jats:italic>Plasmodium</jats:italic> exemplifies an extreme case of signaling plasticity in eukaryotic evolution, demonstrating how essential mTOR‐associated functions can be maintained despite the apparent loss of the pathway itself.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"10 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149151806","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}
Ankita Bhattacharyya,Raymond Yau,Thomas M. Bartlett,Nicholas J. Mantis
{"title":"Rapid Motility Arrest of the Lyme Disease Spirochete,\u0000 Borrelia burgdorferi\u0000 , by Vaccine‐Induced\u0000 OspA\u0000 Antibodies","authors":"Ankita Bhattacharyya,Raymond Yau,Thomas M. Bartlett,Nicholas J. Mantis","doi":"10.1111/mmi.70122","DOIUrl":"https://doi.org/10.1111/mmi.70122","url":null,"abstract":"ABSTRACT Outer surface protein A (OspA)‐based Lyme disease vaccines elicit antibodies that inhibit transmission of infectious Borrelia burgdorferi spirochetes from ticks to humans, although the mechanism by which this occurs is unclear. Here we demonstrate using high‐resolution, single‐cell fluorescence video microscopy that B. burgdorferi motility is arrested within minutes by human OspA‐specific monoclonal antibodies and polyclonal OspA antisera from mice immunized with a candidate OspA mRNA lipid nanoparticle vaccine.","PeriodicalId":19006,"journal":{"name":"Molecular Microbiology","volume":"8 1","pages":""},"PeriodicalIF":3.6,"publicationDate":"2026-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"149090165","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}