Mariprofundus ferroooxydans PV-1 osmotic shock vs extraction with NaOH LC-MSMS
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ABSTRACT: Proteomic analysis was performed on protein extracts of M. ferrooxydans by following two methodologies: osmotic shock and alkalyne lysis (extraction with NaOH).
Project description:A proteomic analysis of a redox active membrane fraction (doublet at >200 kDa) of Mariprofundus ferrooxydans, a chemolithoautotrophic, neutrophilic, iron-oxidizing Zetaproteobacterium.
Project description:5' RNASeq of mRNA from Shewanella loihica PV-4 grown aerobically in Luria-Bertani broth (LB) and defined lactate minimal medium 5'-end mRNA profiles of mid-log phase bacterial cells growing in LB or lactate medium were generated by next-generation sequencing.
Project description:Pseudomonas syringae pv. tomato DC3000 (Pst) is a virulent pathogen, which causes disease on tomato and Arabidopsis. The type III secretion system (TTSS) plays a key role in pathogenesis by translocating virulence effectors from the bacteria into the plant host cell, while the phytotoxin coronatine (COR) contributes to virulence and disease symptom development. Recent studies suggest that both the TTSS and and COR are involved in the suppression of host basal defenses. However, little is known about the interplay between the host gene expression associated with basal defenses and the virulence activities of the TTSS and COR during infection. The global effects of the TTSS and COR on host gene expression associated with other host cellular processes during bacterial infection are also not well characterized. In this study, we used the Affymetrix full genome chip to determine the Arabidopsis transcriptome associated with basal defense to Pst DC3000 hrp mutants and the human pathogenic bacterium Escherichia coli O157:H7. We then used Pst DC3000 virulence mutants to characterize Arabidopsis transcriptional responses to the action of hrp-regulated virulence factors (e.g., TTSS and COR) during bacterial infection. Additionally, we used bacterial fliC mutants to assess the role of the PAMP flagellin in induction of basal defense-associated transcriptional responses. In total, our global gene expression analysis identified more than 5000 Arabidopsis genes that are reproducibly regulated more than 2-fold in three independent biological replicates of at least one type of comparison. Regulation of these genes provides a molecular signature for Arabidopsis basal defense to plant and human pathogenic bacteria, and illustrates both common and distinct global virulence effects of the TTSS, COR, and possibly other hrp-regulated virulence factors during Pst DC3000 infection. Experimenter name = William Underwood; Experimenter phone = 517-353-9182; Experimenter fax = 517-353-9168; Experimenter address = Michigan State University; Experimenter address = 222 Plant Biology Building; Experimenter address = 178 Wilson R.d. Experimenter address = East Lansing, MI; Experimenter zip/postal_code = 48824; Experimenter country = USA Experiment Overall Design: 40 samples were used in this experiment
Project description:A proteomic profile of the chemolithoautotrophic, neutrophilic, iron-oxidizing Mariprofundus ferrooxydans was obtained in duplicates and analyzed via LC-MS/MS. Additionally, a proteomic analysis of the membrane fraction is included.
Project description:Pseudomonas syringae pv. aptata is a member of the sugar beet pathobiome and the causative agent of leaf spot disease. Like many pathogenic bacteria, P. syringae relies on the secretion of toxins, which manipulate host-pathogen interactions, to establish and maintain an infection. This study analyzes the secretome of six pathogenic P. syringae pv. aptata strains with different defined virulence capacities in order to identify common and strain-specific features, and correlate the secretome with disease outcome. All strains show a high type III secretion system (T3SS) and type VI secretion system (T6SS) activity under apoplast-like conditions mimicking the infection. Surprisingly, we found that low pathogenic strains show a higher secretion of most T3SS substrates (19 of the 23 detected effectors and accessory harpin proteins), whereas a distinct subgroup of four effectors is exclusively secreted in medium and high pathogenic strains. Similarly, we detected two T6SS secretion patterns: while one set of proteins was highly secreted in all strains, another subset consisting of known T6SS substrates and previously uncharacterized proteins with a highly similar secretion pattern was exclusively secreted in medium and high virulence strains. Taken together, our data shows that P. syringae pathogenicity is correlated with the repertoire and fine-tuning of effector secretion and indicates distinct strategies for establishing virulence of P. syringae pv. aptata in plants.
Project description:In response to osmolarity, Salmonella enterica serotype Typhi (S. Typhi) regulates genes required for Vi capsular antigen expression oppositely to those required for motility and invasion. Previous studies suggest that osmoregulation of motility, invasion and capsule expression is mediated through the RcsC/RcsD/RcsB phosphorelay system. Here we performed gene expression profiling and functional studies to determine the role of TviA, an auxiliary protein of the RcsB response regulator, in controlling virulence gene expression in S. Typhi. TviA repressed expression of genes encoding flagella and the invasion associated type III secretion system (T3SS-1) through repression of the flagellar regulators flhDC and fliZ, resulting in reduced invasion and reduced expression of FliC. Both RcsB and TviA reduced expression of flhDC, but only TviA altered flhDC expression in response to osmolarity. These data suggest that the auxiliary TviA protein integrates a new regulatory input into the RcsB regulon of S. Typhi, thereby altering expression of genes encoding flagella, the Vi antigen and T3SS-1 in response to osmolarity. Gene expression profiles of the S. Typhi wild-type strain, a rcsB mutant, a (delta)tviB-vexE (tviBCDEvexABCDE) mutant, and a (delta)viaB (tviABCDEvexABCDE) mutant (lacking tviA expression) was compared. Strains were cultured in SOB broth (low salt), a condition known to induce expression of TviA and the RcsCB system. Total RNA was extracted from two independent cultures (biological replicates) of each strain. cDNA was differentially labeled with Alexa Fluor 555 and 648, respectively and competitively hybridized on S.Typhimurium arrays (PFGRC, version 4). The submitted samples are biological replicates of a competitive hybridization of cDNA from the wild-type strain (Ty2) and the rcsB mutant (SW237) (GSM395580, GSM395581) or the viaB mutant (STY2) and the tviB-vexE mutant (SW74) (GSM395582, GSM395583), respectively.
Project description:The protozoan Giardia lamblia is a unique biological model to investigate minimal cellular mechanisms because it is an early‐diverged eukaryote that has undergone reductive evolution and has minimized or lost organelles such as mitochondria, peroxisomes, the endo-lysosomal system and a Golgi apparatus. Giardia trophozoites reside in the host intestines where they largely depend on scavenging metabolites from the surrounding through endocytosis and/or pinocytosis. A canonical endo‐lysosomal system however is inexistent, but small peripheral vesicles (PVs) have been described which have partial endocytic characteristics but lack endocytic hallmarks: (i) unlike the dynamic multivesicular endo-lysosomal system in mammalian cells, PVs have a fixed location at the cell periphery and show no lateral cargo exchange; (ii) PVs lack maturation-specific markers. For transmission to a new host, motile trophozoites differentiate to cysts and thus secrete a protective cyst wall (CW). Giardia however has no Golgi or to organize regulated secretion of CW material. Instead, differentiating cells generate specialized organelles termed encystation‐specific vesicles (ESVs), being stage-regulated Golgi relic organelles dedicated to post‐translational maturation of the CW material. Basic sorting processes in maturing ESVs have been identified recently, but underlying mechanisms remain unknown. To define the first proteome of ESVs and PVs, we used a new strategy combining flow cytometry-based organelle sorting with in silico filtration of mass spectrometry data.
Project description:The transcriptomic modulations leading to defense response in rice one hour after inoculation by Xanthomonas oryzae pv oryzae. Xoo and mock inoculated plant of cultivars IET8585 (bacterial leaf blight resistant) and IR-24 (bacterial leaf blight susceptible) were compared.
Project description:This experiment analyses the expression data of the wild type P. syringae pv. tomato DC3000 grown in the absence and in the presence of phloretin and naringenin.