Read by QxMD icon Read

Type III Secretion System

Jamie L Burgess, R Alan Burgess, Yalemi Morales, Jenna M Bouvang, Sean J Johnson, Nicholas E Dickenson
Like many Gram-negative pathogens, Shigella rely on a complex type three secretion system (T3SS) to inject effector proteins into host cells, take over host functions, and ultimately establish infection. Despite these critical roles, the energetics and regulatory mechanisms controlling the T3SS and pathogen virulence remain largely unclear. In this study, we present a series of high-resolution crystal structures of Spa47 and use the structures to model an activated Spa47 oligomer, finding that ATP hydrolysis may be supported by specific sidechain contributions from adjacent protomers within the complex...
October 21, 2016: Journal of Biological Chemistry
Yuying Sang, Yaru Wang, Hong Ni, Anne-Claire Cazalé, Yi-Min She, Nemo Peeters, Alberto P Macho
The subversion of plant cellular functions is essential for bacterial pathogens to proliferate in host plants and cause disease. Most bacterial plant pathogens employ a type-III secretion system to inject type-III effector (T3E) proteins inside plant cells, where they contribute to the pathogen-induced alteration of plant physiology. In this work, we found that the Ralstonia solanacearum T3E RipAY suppresses plant immune responses triggered by bacterial elicitors and by the phytohormone salicylic acid. Further biochemical analysis indicated that RipAY associates in planta with thioredoxins from Nicotiana benthamiana and Arabidopsis...
October 21, 2016: Molecular Plant Pathology
Melissa Agnello, Steven E Finkel, Annie Wong-Beringer
Fluoroquinolone (FQ) resistance is highly prevalent among clinical strains of Pseudomonas aeruginosa, limiting treatment options. We have reported previously that highly virulent strains containing the exoU gene of the type III secretion system are more likely to be FQ-resistant than strains containing the exoS gene, as well as more likely to acquire resistance-conferring mutations in gyrA/B and parC/E. We hypothesize that FQ-resistance imposes a lower fitness cost on exoU compared to exoS strains, thus allowing for better adaptation to the FQ-rich clinical environment...
2016: Frontiers in Microbiology
Dominic J Pollard, Joanna C Young, Valentina Covarelli, Silvia Herrera-León, Thomas R Connor, Maria Fookes, Danielle Walker, Aurora Echeita, Nicholas R Thomson, Cedric N Berger, Gad Frankel
Salmonella spp. utilize type III secretion systems (T3SS) to translocate effectors into the cytosol of mammalian host cells, subverting cell signaling and facilitating the onset of gastroenteritis. In this study we compared a draft genome assembly of S. enterica subsp. salamae strain 3588/07 (S. salamae) against the genomes of S. enterica subsp. enterica serovar Typhimurium strain LT2 and S. bongori strain 12419. S. salamae encode the Salmonella pathogenicity island (SPI)-1; SPI-2 and the locus of enterocyte effacement (LEE) T3SSs...
October 10, 2016: Infection and Immunity
Junlei Yin, Yun Chen, Xiaolei Xie, Jie Xia, Qiuchun Li, Shizhong Geng, Xinan Jiao
Salmonella pathogenicity island 2 (SPI2) can encode type III secretion system 2 (T3SS2) which plays an important role in systemic disease development through delivering different effector proteins into host cells. Here, the influence of Salmonella Pullorum pathogenicity island 2 on T3SS2 effetor gene expression was performed using qRT-PCR in chicken macrophage HD11 cells. Our results showed that all the detected genes (including pseudogenes sifB, sspH2 and steC) can express in HD11 cells of Salmonella Pullorum infection, deletion of SPI2 of Salmonella Pullorum did not significantly affect the expression of genes cigR, gtgA, slrP, sopD, sseK1, steB and steC, but had a significantly effect on the expression of genes pipB2, sifB, sopD2, sseJ, sseL, sspH2, steD, sifA, pipB and steA at different degrees...
October 13, 2016: Avian Pathology: Journal of the W.V.P.A
Tatyana Goldberg, Burkhard Rost, Yana Bromberg
Type III secretion system is a key bacterial symbiosis and pathogenicity mechanism responsible for a variety of infectious diseases, ranging from food-borne illnesses to the bubonic plague. In many Gram-negative bacteria, the type III secretion system transports effector proteins into host cells, converting resources to bacterial advantage. Here we introduce a computational method that identifies type III effectors by combining homology-based inference with de novo predictions, reaching up to 3-fold higher performance than existing tools...
October 7, 2016: Scientific Reports
Alexandra Vergnes, Julie P M Viala, Rabah Ouadah-Tsabet, Bérengère Pocachard, Laurent Loiseau, Stéphane Méresse, Frédéric Barras, Laurent Aussel
Iron-sulfur (Fe-S)-containing proteins contribute to various biological processes, including redox reactions or regulation of gene expression. Living organisms have evolved by developing distinct biosynthetic pathways to assemble these clusters, including ISC (Iron Sulfur Cluster) and SUF (Sulfur mobilization). Salmonella enterica serovar Typhimurium is an intracellular pathogen responsible for a wide range of infections, from gastroenteritis to severe systemic diseases. Salmonella possesses all known prokaryotic systems to assemble Fe-S clusters, including ISC and SUF...
October 5, 2016: Cellular Microbiology
Farzaneh Moghadam, M B Couger, Breeanna Russ, Randi Ramsey, Radwa A Hanafy, Connie Budd, Donald P French, Wouter D Hoff, Noha Youssef
The genus Pantoea is a predominant member of host-associated microbiome. We here report on the genomic analysis of Pantoea eucrina strain Russ that was isolated from a trashcan at Oklahoma State University, Stillwater, OK. The draft genome of Pantoea eucrina strain Russ consists of 3,939,877 bp of DNA with 3704 protein-coding genes and 134 RNA genes. This is the first report of a genome sequence of a member of Pantoea eucrina. Genomic analysis revealed metabolic versatility with genes involved in the metabolism and transport of all amino acids as well as glucose, fructose, mannose, xylose, arabinose and galactose, suggesting the organism is a versatile heterotroph...
December 2016: Genomics Data
Fazal Wahab, Muhammad Shahab, Rüdiger Behr
A large body of data suggests that body weight influences puberty onset and adult reproduction. However, the underlying mechanism of how body weight influences puberty onset and fertility is not completely understood. The hypothalamic neuronal circuit regulating reproduction is restrained by inhibitory signals during childhood. At the time of puberty, these inhibitory signals are weakened and supplanted by stimulatory signals that, in turn, stimulate the release of gonadotropin-releasing hormone (GnRH) - a hypothalamic neuropeptide governing reproduction...
October 2016: Medical Hypotheses
Fumiaki Makino, Dakang Shen, Naoko Kajimura, Akihiro Kawamoto, Panayiota Pissaridou, Henry Oswin, Maria Pain, Isabel Murillo, Keiichi Namba, Ariel J Blocker
Type III secretion systems (T3SSs) are essential devices in the virulence of many Gram-negative bacterial pathogens. They mediate injection of protein effectors of virulence from bacteria into eukaryotic host cells to manipulate them during infection. T3SSs involved in virulence (vT3SSs) are evolutionarily related to bacterial flagellar protein export apparatuses (fT3SSs), which are essential for flagellar assembly and cell motility. The structure of the external and transmembrane parts of both fT3SS and vT3SS is increasingly well-defined...
September 30, 2016: Scientific Reports
Hao Tan, Lu Zhang, Qiang Zhao, Ronghao Chen, Chang Liu, Yuding Weng, Qianqian Peng, Fang Bai, Zhihui Cheng, Shouguang Jin, Weihui Wu, Yongxin Jin
DExD/H box RNA helicases play essential roles in various biological processes in prokaryotes and eukaryotes. By screening Pseudomonas aeruginosa strains with mutations in various DExD/H box helicase genes, we identified that deaD was required for bacterial cytotoxicity and virulence in a mouse acute pneumonia model. Compared to a wild-type strain and its complementation strain, the deaD mutant induced less production of proinflammatory cytokines, neutrophil infiltration and lung damage during infection. We further found that the RNA helicase activity of DeaD was required for the expression of type III secretion system (T3SS) genes...
October 2016: FEMS Microbiology Letters
Christopher D A Rodrigues, Xavier Henry, Emmanuelle Neumann, Vilius Kurauskas, Laure Bellard, Yann Fichou, Paul Schanda, Guy Schoehn, David Z Rudner, Cecile Morlot
During spore formation in Bacillus subtilis a transenvelope complex is assembled across the double membrane that separates the mother cell and forespore. This complex (called the "A-Q complex") is required to maintain forespore development and is composed of proteins with remote homology to components of type II, III, and IV secretion systems found in Gram-negative bacteria. Here, we show that one of these proteins, SpoIIIAG, which has remote homology to ring-forming proteins found in type III secretion systems, assembles into an oligomeric ring in the periplasmic-like space between the two membranes...
October 11, 2016: Proceedings of the National Academy of Sciences of the United States of America
Yvonne T Wu, Connie Tam, Lucia S Zhu, David J Evans, Suzanne M J Fleiszig
PURPOSE: The type III secretion system (T3SS) is a significant virulence determinant for Pseudomonas aeruginosa. Using a rodent model, we found that contact lens (CL)-related corneal infections were associated with lens surface biofilms. Here, we studied the impact of human tear fluid on CL-associated biofilm growth and T3SS expression. METHODS: P. aeruginosa biofilms were formed on contact lenses for up to 7 days with or without human tear fluid, then exposed to tear fluid for 5 or 24 h...
September 23, 2016: Ocular Surface
Cecilia M Duarte, Laura A Basile, Andrés Zalguizuri, Viviana C Lepek
Mesorhizobium loti MAFF303099 has a functional Type III secretion system (T3SS) that is involved in the determination of competitiveness for legume nodulation. Here we demonstrate that the transcriptional factor TtsI, which positively regulates T3SS genes expression, is involved in a negative regulation of M. loti swimming motility in soft-agar. Conditions that induce T3SS expression affect flagella production. The same conditions also affect promoter activity of M. loti visN gene, a homolog to the positive regulator of flagellar genes that has been described in other rhizobia...
September 22, 2016: FEMS Microbiology Letters
Christopher A Lopez, Brittany M Miller, Fabian Rivera-Chávez, Eric M Velazquez, Mariana X Byndloss, Alfredo Chávez-Arroyo, Kristen L Lokken, Renée M Tsolis, Sebastian E Winter, Andreas J Bäumler
Citrobacter rodentium uses a type III secretion system (T3SS) to induce colonic crypt hyperplasia in mice, thereby gaining an edge during its competition with the gut microbiota through an unknown mechanism. Here, we show that by triggering colonic crypt hyperplasia, the C. rodentium T3SS induced an excessive expansion of undifferentiated Ki67-positive epithelial cells, which increased oxygenation of the mucosal surface and drove an aerobic C. rodentium expansion in the colon. Treatment of mice with the γ-secretase inhibitor dibenzazepine to diminish Notch-driven colonic crypt hyperplasia curtailed the fitness advantage conferred by aerobic respiration during C...
September 16, 2016: Science
Wen-Tyng Kang, Kumutha Malar Vellasamy, Jamuna Vadivelu
Burkholderia pseudomallei, the etiological agent for melioidosis, is known to secrete a type III secretion system (TTSS) protein into the host's internal milieu. One of the TTSS effector protein, BipC, has been shown to play an important role in the B. pseudomallei pathogenesis. To identify the host response profile that was directly or indirectly regulated by this protein, genome-wide transcriptome approach was used to examine the gene expression profiles of infected mice. The transcriptome analysis of the liver and spleen revealed that a total of approximately 1,000 genes were transcriptionally affected by BipC...
2016: Scientific Reports
Michael Eschbaumer, Carolina Stenfeldt, Steven I Rekant, Juan M Pacheco, Ethan J Hartwig, George R Smoliga, Mary A Kenney, William T Golde, Luis L Rodriguez, Jonathan Arzt
BACKGROUND: In order to investigate host factors associated with the establishment of persistent foot-and-mouth disease virus (FMDV) infection, the systemic response to vaccination and challenge was studied in 47 steers. Eighteen steers that had received a recombinant FMDV A vaccine 2 weeks earlier and 29 non-vaccinated steers were challenged by intra-nasopharyngeal deposition of FMDV A24. For up to 35 days after challenge, host factors including complete blood counts with T lymphocyte subsets, type I/III interferon (IFN) activity, neutralizing and total FMDV-specific antibody titers in serum, as well as antibody-secreting cells (in 6 non-vaccinated animals) were characterized in the context of viral infection dynamics...
2016: BMC Veterinary Research
Victoria Auerbuch
Inflammasome-associated innate immune receptors sense host-cell targeting by the type III secretion system (T3SS) of pathogenic Yersinia. In this issue of Cell Host & Microbe, Chung et al. (2016) show that the Yersinia T3SS effector protein YopM counteracts this recognition pathway by restricting the pyrin inflammasome, thus increasing bacterial fitness.
September 14, 2016: Cell Host & Microbe
Shaohui Wang, Xin Liu, Xuan Xu, Denghui Yang, Dong Wang, Xiangan Han, Yonghong Shi, Mingxing Tian, Chan Ding, Daxin Peng, Shengqing Yu
Type III secretion systems (T3SSs) are crucial for bacterial infections because they deliver effector proteins into host cells. The Escherichia coli type III secretion system 2 (ETT2) is present in the majority of E. coli strains, and although it is degenerate, ETT2 regulates bacterial virulence. An ATPase is essential for T3SS secretion, but the function of the ETT2 ATPase has not been demonstrated. Here, we show that EivC is homologous to the β subunit of F0F1 ATPases and it possesses ATPase activity. To investigate the effects of ETT2 ATPase EivC on the phenotype and virulence of avian pathogenic Escherichia coli (APEC), eivC mutant and complemented strains were constructed and characterized...
2016: Frontiers in Microbiology
M A Pallett, V F Crepin, N Serafini, M Habibzay, O Kotik, J Sanchez-Garrido, J P Di Santo, A R Shenoy, C N Berger, G Frankel
The human pathogen enteropathogenic Escherichia coli (EPEC), as well as the mouse pathogen Citrobacter rodentium, colonize the gut mucosa via attaching and effacing lesion formation and cause diarrheal diseases. EPEC and C. rodentium type III secretion system (T3SS) effectors repress innate immune responses and infiltration of immune cells. Inflammatory caspases such as caspase-1 and caspase-4/11 are crucial mediators of host defense and inflammation in the gut via their ability to process cytokines such as interleukin (IL)-1β and IL-18...
September 14, 2016: Mucosal Immunology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"