In cells that exhibit apical growth, mechanisms regulate cell polarity are crucial for determination of cellular shape and the adaptation growth to intrinsic extrinsic cues. Broadly conserved pathways control in eukaryotes, but less is known about polarly growing prokaryotes. An evolutionarily ancient form found filamentous bacteria Streptomyces , directed by a polarisome-like complex involving essential protein DivIVA. We report here this bacterial polarization machinery regulated...

Significance Here, we show that FilP, a bacterial cytoskeletal protein related to metazoan intermediate filament (IF) proteins, can self-assemble into regular network structure. This finding offers possible explanation for its previously characterized role in cellular rigidity and elasticity might offer insights the mechanical of human IFs. The assembly FilP cytoskeleton is coupled function polarisome, complex orchestrating polar growth characteristic Streptomyces . These results suggest...

Peptidoglycan (PG), the main component of bacterial cell wall, plays a fundamental role in maintaining shape, integrity, and resistance to osmotic pressure. Preliminary observations suggested that unlike typical bacteria, Francisella tularensis infrequently produces detectable PG while growing rich liquid media. However, increasing salt concentration induces production all bacteria. In this study, we confirmed extended these by incubating bacteria with fluorescent D-alanine (which integrates...

Francisella tularensis is a tier 1 select agent that causes the potentially fatal disease Tularemia. F. has been designated based on its potential for use as bioweapon. The CDC describes symptoms of Tularemia vary from skin ulcers to pneumonia, differ route infection. an airborne pathogen, however contact with contaminated water and arthropod bites also risk Relatively little known about cell division processes tularensis, however, genome contains homologs key wall (dcw) genes have...

Francisella tularensis is a gram-negative bacterium categorized as tier 1 select agent. Fatal disease can be caused by very low doses, leading to the potential of F. being used bioterror Understanding cell division in could yield important insights for development vaccine or antimicrobial treatments. how divides may also shed light on able enter Viable-but-not-Culturable (VBNC) state. This VBNC state contributing factor survival environment and during phagocytosis into host cells. Known...

The central player in bacterial cell division, FtsZ, is essential almost all organisms which it has been tested, with the most notable exception being Streptomyces. Streptomycetes differ from many bacteria growing tip and undergoing branching, similar to filamentous fungi. Here we show that limited damage, either mechanical or enzymatic, leads near complete destruction of mycelial microcolonies a Streptomyces venezuelae ftsZ mutant. This result consistent lack ftsZ-dependent cross-walls may...

Francisella tularensis is a gram-negative, intracellular pathogen which can cause serious, potentially fatal, illness in humans. Species of F. are found across the Northern Hemisphere and infect broad range host species, including Factors affecting persistence environment its epidemiology not well understood, however, ability to enter viable but non-culturable state (VBNC) may be important. A bacteria, many pathogens, have been observed VBNC response stressful environmental conditions, such...

The coiled-coil protein DivIVA is a determinant of apical growth and hyphal branching in Streptomyces coelicolor. We have investigated the properties this involvement different domains its essential function subcellular targeting. In S. coelicolor cell extracts, was present as large oligomeric complexes that were not strongly membrane associated. purified could self-assemble into extensive filaments vitro. Two conspicuous segments amino acid sequence streptomycete DivIVAs other homologs, an...

The sporulating, filamentous soil bacterium Streptomyces venezuelae ATCC 10712 differentiates under submerged and surface growth conditions. In order to lay a solid foundation for the study of development-associated division this organism, congenic set mutants was isolated, individually deleted gene encoding either cytoplasmic (i.e. ftsZ) or core inner membrane divIC, ftsL, ftsI, ftsQ, ftsW) component divisome. While ftsZ are completely blocked division, single in other divisome genes...

Francisella tularensis is an intracellular pathogen and the causative agent of tularemia. The F. type six secretion system (T6SS) required for a number host-pathogen interactions, including phagolysosomal escape invasion erythrocytes. One known effector T6SS, OpiA, has recently been shown to be phosphatidylinositol-3 kinase. To investigate role OpiA in erythrocyte invasion, we constructed opiA-null mutant live vaccine strain, LVS. was not invasion; however, deletion opiA affected growth LVS...

Abstract Members of the Actinobacteria, including mycobacteria and streptomycetes, exhibit a distinctive mode polar growth, with cell wall synthesis occurring in zones at poles directed by essential polarity determinant DivIVA. Streptomyces coelicolor modulates growth via Ser/Thr protein kinase AfsK, which phosphorylates Here, we show that phosphoprotein phosphatase SppA has strong effects on shape it reverses AfsK‐mediated phosphorylation affects hyphal branching rate tip extension. The...

Francisella tularensis is a gram negative, intracellular pathogen that the causative agent of potentially fatal disease, tularemia. During infection, F. engulfed by and replicates within host macrophages. Additionally, this bacterium has also been shown to invade human erythrocytes and, in both cases, Type Six Secretion System (T6SS) required for these host-pathogen interaction. One T6SS effector protein, PdpC, important macrophage playing role phagolysosomal escape replication. To determine...

Utilization of fluorescent proteins is widespread for the study microbial pathogenesis and host-pathogen interactions. Here, we discovered that linkage 36 N-terminal amino acids FTL_0580 (a hypothetical protein Francisella tularensis) to increases fluorescence emission bacteria express these recombinant fusions. This peptide will be referred as 580N. Western blotting revealed 580N Emerald Green Fluorescent Protein (EmGFP) in F. tularensis markedly improved detection this protein. We...

Abstract Bacteria that exhibit polar growth, i.e. build their peptidoglycan cell walls in restricted zones at poles, often show large morphological diversity and plasticity. However, mechanisms for regulation of shape wall assembly are poorly understood. The Gram-positive Streptomyces bacteria, like other Actinobacteria, depend on the essential coiled coil protein DivIVA establishment polarity direction growth. Streptomycetes grow as filamentous hyphae tip extension. New hyphal tips...

Insects are now well recognized as biologically relevant alternative hosts for dozens of mammalian pathogens and they routinely used in microbial pathogenesis studies. Unfortunately, these models have yet to be incorporated into the drug development pipeline. The purpose this work was begin evaluate utility orange spotted (Blaptica dubia) cockroaches early antibiotic characterization. To determine whether model could exhibit mortality when infected with bacteria that pathogenic humans, we...

Many species of bacteria, under conditions stress or nutrient limitation, enter a state dormancy referred to as viable but non-culturable (VBNC). VBNC bacteria persist in the environment, are difficult detect and identify by many standard laboratory methods can be altered their susceptibility antibiotics. Entry into is often accompanied morphological changes; however, mechanisms underlying this poorly understood. Francisella transitions rapidly spontaneously state, therefore has potential an...

With antibiotic resistance on the rise, it is important that scientific community continues to advance our understanding of antibiotics and grow medicinal arsenal treatments. The potential exists for many novel compounds be discovered from fungal extracts can save lives, following suit one earliest characterized antibiotics, penicillin. These fungal-derived used as new therapeutics treat infections have developed current antibiotics. A variety types fungi produce secondary metabolites are...

Francisella tularensis is a bacterium that induces the zoonotic disease tularemia. In course of infection, F. bacteria invade erythrocytes, phenomenon heightens colonization ticks after blood meal. To better understand mechanism erythrocyte invasion, we hypothesized transcription bacterial genes significant in invasion would be upregulated upon exposure to these host cells. An RNA-seq unveiled 7% augment when presence. Of these, pinpointed putative transcriptional regulator, FTL_1199. The...

CARLY CUNNINGHAM, STUART CANTLAY, AND JOSEPH HORZEMPA, Department of Natural Sciences and Mathematics, West Liberty University, Liberty, WV USA. The ability VBNC F. tularensis to replicate within THP-1 cells. Francisella tularensis, a gram-negative coccobacillus is the causative agent tularemia, potentially fatal zoonotic disease. Under laboratory conditions, enters viable but non-culturable (VBNC) state. state dormancy bacteria enter during stressful conditions can have implications for...

Francisella tularensis is a gram-negative, intracellular pathogen capable of causing infection at low dose <10 CFU. For this reason, bacterium has been classified as Category A Bioterrorism Agent by the Center for Disease Control (CDC). Fluorescence microscopy valuable tool that investigators can utilize to study many interactions between F. and its host cells. However, in our hands, only weakly fluorescent when expressing certain proteins such emGFP BFP using previously described...

Francisella tularensis, the causative agent of tularemia, is a highly infectious gram-negative bacterium capable replicating within macrophages, leukocytes, dendritic cells and epithelial cells. In addition, F. tularensis also invades erythrocytes. FtsZ, homologue eukaryotic tubulin, an essential cell division protein in almost all bacteria. Polymerization FtsZ into contractile ring critical first step acts recruiting wall synthesis machinery to nascent septum. We have generated recombinant...

Francisella tularensis is a gram-negative, intracellular pathogen capable of establishing lethal infection at dose <10 CFU. Fluorescence microscopy vital tool used to study F. host-pathogen interactions. However, only weakly fluorescent when expressing proteins such as emGFP and BFP using previously described molecular tools. In contrast, our laboratory robust expression tdTomato while under the control glucose-repressible promoter (FGRp; plasmid construct pTC3D). bacteria were unable...