scholarly journals Strain-specific impact of PsaR of Streptococcus pneumoniae on global gene expression and virulence

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1569-1579 ◽  
Author(s):  
Wouter T. Hendriksen ◽  
Hester J. Bootsma ◽  
Angela van Diepen ◽  
Silvia Estevão ◽  
Oscar P. Kuipers ◽  
...  
Keyword(s):  
Gene Expression ◽  
Streptococcus Pneumoniae ◽  
Microarray Analysis ◽  
Proteome Analysis ◽  
Global Gene Expression ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Infection Models ◽  
Shared Gene ◽  
Specific Impact

Previous studies have indicated that PsaR of Streptococcus pneumoniae is a manganese-dependent regulator, negatively affecting the expression of at least seven genes. Here, we extended these observations by transcriptome and proteome analysis of psaR mutants in strains D39 and TIGR4. The microarray analysis identified three shared PsaR targets: the psa operon, pcpA and prtA. In addition, we found 31 genes to be regulated by PsaR in D39 only, most strikingly a cellobiose-specific phosphotransferase system (PTS) and a putative bacteriocin operon (sp0142–sp0146). In TIGR4, 14 PsaR gene targets were detected, with the rlrA pathogenicity islet being the most pronounced. Proteomics confirmed most of the shared gene targets. To examine the contribution of PsaR to pneumococcal virulence, we compared D39 and TIGR4 wild-type (wt) and psaR mutants in three murine infection models. During colonization, no clear effect was observed of the psaR mutation in either D39 or TIGR4. In the pneumonia model, small but significant differences were observed in the lungs of mice infected with either D39wt or ΔpsaR: D39ΔpsaR had an initial advantage in survival in the lungs. Conversely, TIGR4ΔpsaR-infected mice had significantly lower bacterial loads at 24 h only. Finally, during experimental bacteraemia, D39ΔpsaR-infected mice had significantly lower bacterial loads in the bloodstream than wt-infected mice for the first 24 h of infection. TIGR4ΔpsaR showed attenuation at 36 h only. In conclusion, our results show that PsaR of D39 and TIGR4 has a strain-specific role in global gene expression and in the development of bacteraemia in mice.

Global analysis of gene expression in an rpoN mutant of Listeria monocytogenes

Microbiology ◽  
2004 ◽  
Vol 150 (5) ◽  
pp. 1581-1590 ◽  
Author(s):  
Safia Arous ◽  
Carmen Buchrieser ◽  
Patrice Folio ◽  
Philippe Glaser ◽  
Abdelkader Namane ◽  
...  
Keyword(s):  
Gene Expression ◽  
Listeria Monocytogenes ◽  
Carbohydrate Metabolism ◽  
Global Analysis ◽  
Global Gene Expression ◽  
Mutant Gene ◽  
Wild Type ◽  
Phosphotransferase System ◽  
Two Dimensional Gel Electrophoresis ◽  
Catabolite Regulation

The role of the alternative σ 54 factor, encoded by the rpoN gene, was investigated in Listeria monocytogenes by comparing the global gene expression of the wild-type EGDe strain and an rpoN mutant. Gene expression, using whole-genome macroarrays, and protein content, using two-dimensional gel electrophoresis, were analysed. Seventy-seven genes and nine proteins, whose expression was modulated in the rpoN mutant as compared to the wild-type strain, were identified. Most of the modifications were related to carbohydrate metabolism and in particular to pyruvate metabolism. However, under the conditions studied, only the mptACD operon was shown to be directly controlled by σ 54. Therefore, the remaining modifications seem to be due to indirect effects. In parallel, an in silico analysis suggests that σ 54 may directly control the expression of four different phosphotransferase system (PTS) operons, including mptACD. PTS activity is known to have a direct effect on the pyruvate pool and on catabolite regulation. These results suggest that σ 54 is mainly involved in the control of carbohydrate metabolism in L. monocytogenes via direct regulation of PTS activity, alteration of the pyruvate pool and modulation of carbon catabolite regulation.

scholarly journals Role of Sigma Factors in Controlling Global Gene Expression in Light/Dark Transitions in the Cyanobacterium Synechocystis sp. Strain PCC 6803

2007 ◽  
Vol 189 (21) ◽  
pp. 7829-7840 ◽  
Author(s):  
Tina C. Summerfield ◽  
Louis A. Sherman
Keyword(s):  
Gene Expression ◽  
Global Gene Expression ◽  
Growth Conditions ◽  
Day Length ◽  
Regulation Of Transcription ◽  
Wild Type ◽  
Protein Levels ◽  
In The Wild ◽  
Altered Gene ◽  
Pcc 6803

ABSTRACT We report on differential gene expression in the cyanobacterium Synechocystis sp. strain PCC 6803 after light-dark transitions in wild-type, ΔsigB, and ΔsigD strains. We also studied the effect of day length in the presence of glucose on a ΔsigB ΔsigE mutant. Our results indicated that the absence of SigB or SigD predominately altered gene expression in the dark or in the light, respectively. In the light, approximately 350 genes displayed transcript levels in the ΔsigD strain that were different from those of the wild type, with over 200 of these up-regulated in the mutant. In the dark, removal of SigB altered more than 150 genes, and the levels of 136 of these were increased in the mutant compared to those in the wild type. The removal of both SigB and SigE had a major impact on gene expression under mixotrophic growth conditions and resulted in the inability of cells to grow in the presence of glucose with 8-h light and 16-h dark cycles. Our results indicated the importance of group II σ factors in the global regulation of transcription in this organism and are best explained by using the σ cycle paradigm with the stochastic release model described previously (R. A. Mooney, S. A. Darst, and R. Landick, Mol. Cell 20:335-345, 2005). We combined our results with the total protein levels of the σ factors in the light and dark as calculated previously (S. Imamura, S. Yoshihara, S. Nakano, N. Shiozaki, A. Yamada, K. Tanaka, H. Takahashi, M. Asayama, and M. Shirai, J. Mol. Biol. 325:857-872, 2003; S. Imamura, M. Asayama, H. Takahashi, K. Tanaka, H. Takahashi, and M. Shirai, FEBS Lett. 554:357-362, 2003). Thus, we concluded that the control of global transcription is based on the amount of the various σ factors present and able to bind RNA polymerase.

scholarly journals Comparison of the Hepatic Effects of Phenobarbital in Chimeric Mice Containing Either Rat or Human Hepatocytes With Humanized Constitutive Androstane Receptor and Pregnane X Receptor Mice

2020 ◽  
Vol 177 (2) ◽  
pp. 362-376
Author(s):  
Tomoya Yamada ◽  
Ayako Ohara ◽  
Naoya Ozawa ◽  
Keiko Maeda ◽  
Miwa Kondo ◽  
...  
Keyword(s):  
Gene Expression ◽  
Liver Tumor ◽  
Constitutive Androstane Receptor ◽  
Pregnane X Receptor ◽  
Rat Hepatocytes ◽  
Global Gene Expression ◽  
Human Hepatocytes ◽  
Chimeric Mouse ◽  
Chimeric Mice ◽  
Wild Type

Abstract Using a chimeric mouse humanized liver model, we provided evidence that human hepatocytes are refractory to the mitogenic effects of rodent constitutive androstane receptor (CAR) activators. To evaluate the functional reliability of this model, the present study examined mitogenic responses to phenobarbital (PB) in chimeric mice transplanted with rat hepatocytes, because rats are responsive to CAR activators. Treatment with 1000 ppm PB for 7 days significantly increased replicative DNA synthesis (RDS) in rat hepatocytes of the chimeric mice, demonstrating that the transplanted hepatocyte model is functionally reliable for cell proliferation analysis. Treatment of humanized CAR and pregnane X receptor (PXR) mice (hCAR/hPXR mice) with 1000 ppm PB for 7 days significantly increased hepatocyte RDS together with increases in several mitogenic genes. Global gene expression analysis was performed with liver samples from this and from previous studies focusing on PB-induced Wnt/β-catenin signaling and showed that altered genes in hCAR/hPXR mice clustered most closely with liver tumor samples from a diethylnitrosamine/PB initiation/promotion study than with wild-type mice. However, different gene clusters were observed for chimeric mice with human hepatocytes for Wnt/β-catenin signaling when compared with those of hCAR/hPXR mice, wild-type mice, and liver tumor samples. The results of this study demonstrate clear differences in the effects of PB on hepatocyte RDS and global gene expression between human hepatocytes of chimeric mice and hCAR/hPXR mice, suggesting that the chimeric mouse model is relevant to humans for studies on the hepatic effects of rodent CAR activators whereas the hCAR/hPXR mouse is not.

The role of the Shigella flexneri yihE gene in LPS synthesis and virulence

Microbiology ◽  
2004 ◽  
Vol 150 (4) ◽  
pp. 1079-1084 ◽  
Author(s):  
Bryn Edwards-Jones ◽  
Paul R. Langford ◽  
J. Simon Kroll ◽  
Jun Yu
Keyword(s):  
Gene Expression ◽  
Global Change ◽  
Unknown Function ◽  
Guinea Pigs ◽  
Antimicrobial Agents ◽  
Shigella Flexneri ◽  
Global Gene Expression ◽  
Wild Type ◽  
In Trans

Previously, the authors have shown that inactivation of Shigella flexneri yihE, a gene of unknown function upstream of dsbA, which encodes a periplasmic disulphide catalyst, results in a global change of gene expression. Among the severely down-regulated genes are galETKM, suggesting that the yihE mutant, Sh54, may inefficiently produce the UDP-glucose and UDP-galactose required for LPS synthesis. This paper demonstrates that LPS synthesis in Sh54 is impaired. As a result, Sh54 is unable to polymerize host cell actin, due to aberrant localization of IcsA, or to cause keratoconjunctivitis in guinea pigs. Furthermore, Sh54 is more sensitive to some antimicrobial agents, and exhibits epithelial cytotoxicity characteristic of neither wild-type nor dsbA mutants. Supplying galETK in trans restores LPS synthesis and corrects all the defects. Hence, it is clear that the Shigella yihE gene is important not only in regulating global gene expression, as shown previously, but also in virulence through LPS synthesis via regulating the expression of the galETK operon.

The Interaction of MOZ-TIF2 with Histone Chaperon Proteins CAF-1A and Asf1b Alters MOZ Regulated Gene Expression.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 2208-2208
Author(s):  
Hong Yin ◽  
Jonathan Glass ◽  
Kerry L. Blanchard
Keyword(s):  
Gene Expression ◽  
Gene Expression Profile ◽  
Expression Profile ◽  
Global Gene Expression ◽  
Chromatin Assembly ◽  
Wild Type ◽  
Terminal Portion ◽  
Hek 293 ◽  
Assembly Factors ◽  
Regulated Gene Expression

Abstract We have identified a MOZ-TIF2 (MT2) fusion gene containing the N-terminal portion of MOZ and the C-terminal portion of TIF2 from a patient with acute leukemia with a chromosome 8 translocation. We report here that MOZ portion of MOZ-TIF2 associates with chromatin assembly factors, CAF1 (chromatin assembly factor 1) and ASF1 (anti-silencing factor 1) in mammalian cells. Both proteins not only bring histones to newly synthesized DNA to create chromatin structure in the replication of chromosomes and DNA damage-repair processes but also contribute to regulation of global gene expression. Using the MOZ portion of MT2 as the bait in the yeast two hybrid system, we found that the MOZ portion interacted with CAF1A and Asf1b. The interactions were further verified with GST-pull down experiments. Interestingly, co-immunoprecipitation with whole cell extracts from HEK 293 cells transiently transfected with GFP fusions of MOZ, MT2, and TIF2 showed that only MOZ strongly co-precipitated with CAF1A while MT2 only weakly co-precipitated. In contrast to CAF1A, MT2 showed a 3-fold stronger binding to Asf1b than wild type MOZ in pull-down experiments using S-tagged Asf1b and EGFP-fusions of MOZ, MT2, and TIF2. Further analysis of the domains within the MOZ portion of MT2 responsible for the interaction of CAF1A and Asf1b with MT2 indicated that the binding of CAF1A predominately depended on the PHD domain of MOZ and amino acids176–327 of CAF1A. The MYST domain of MOZ was responsible for the binding of the MOZ portion of MT2 to Asf1b. To further verify the differential binding of MOZ and MT2 to CAF1A and Asf1b, we observed the co-localization of transiently expressed EGFP-MOZ and EGFP-MT2 with DsRed-CAF1A in HEK 293 and Hela cells. In the merged images the MOZ co-localization with CAF-1A was stronger than the colocalization of MT2 with CAF1A and MT2 colocalization with Asf1b was stronger than MOZ colocalization with Asf1b. The co-localization of MOZ and MT2 with CAF1A with Asf1b was seen both in interphase and metaphase of the cell cycle. During the interphase, the co-localizations appeared with chromatin DNA and during metaphase the co-localizations were separated from chromatin DNA. The later phenomenon was further demonstrated with G2/M phase reagent, nocodozole. These results suggest a differential function of MT2 interacting with two chromatin assembly factors compared to wild-type MOZ. In view of the regulation of global gene expression by CAF1A and Asf1b, we examined the gene expression profile in U937 cells stably expressing MT2. Compared to the expression profile of control cells stably transfected with pcDNA3 vector alone, MT2 caused a > 5-fold change in expression 181 genes (104 genes increasing and 77 genes decreasing expression) (p = 0.05). While overexpression of wild type MOZ also altered gene expression (>5-fold increase in 479 genes and >5-fold decrease in 118 genes) a differential gene expression signature was seen between MOZ and MT2. MT2 altered expression of 57% of the 597 MOZ regulated genes. Included in the genes that were either up or down-regulated by MT2 were genes involved in multiple cell functions such as signal transduction, cell response to stimulus, and development. These results suggest that MT2 fusion may interfere with the function of wild type MOZ in global gene expression during the development of myeloid cells by differential interaction with chromatin chaperon proteins and the altered global gene expression profile could contribute to leukemogenesis.

scholarly journals Transcriptome Sequencing Data of Bacillus anthracis Vollum ΔhtrA and Its Parental Strain, Isolated under Oxidative Stress

2020 ◽  
Vol 9 (35) ◽  
Author(s):  
Theodor Chitlaru ◽  
Inbar Cohen-Gihon ◽  
Ofir Israeli ◽  
Uri Elia ◽  
Galia Zaide ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Bacillus Anthracis ◽  
Transcriptome Sequencing ◽  
Global Gene Expression ◽  
Data Sets ◽  
Transcriptome Data ◽  
Wild Type ◽  
Sequencing Data ◽  
Content Type

ABSTRACT The high-temperature requirement chaperone/protease (HtrA) is involved in the stress response of the anthrax-causing pathogen Bacillus anthracis. Resilience to oxidative stress is essential for the manifestation of B. anthracis pathogenicity. Here, we announce transcriptome data sets detailing global gene expression in B. anthracis wild-type and htrA-disrupted strains following H2O2-induced oxidative stress.

Sign in / Sign up

Export Citation Format

Share Document