Project description:Time course experiment to analyze transcriptional changes to the E. coli transcriptome due to overexpressing the heterologous sigma70 factor (RpoD) of Lactobacillus plantarum. A plasmid control strain (pControl) and the sigma70 overexpression strain (pLPLσ) were cultivated in parallel and after induction of RpoD expression samples for transcriptional profiling were taken in exponential, transition and stationary phase.
Project description:Housekeeping sigma factors in the Sigma70 family, as components of the RNA polymerase holoenzyme, are responsible for regulating transcription of genes related to vegetative growth. While these factors are well understood in model organisms such as Escherchia coli and Bacillus subtilis, little experimental work has focused on the sigma factors in members of the Lactobacillus genus such as Lactobacillus brevis and Lactobacillus plantarum. This study evaluates the ability of putative Sigma70 proteins from L. brevis (Sigma70-Lb) and L. plantarum (Sigma70-Lp) to complement a temperature sensitive mutation in E. coli 285c Sigma70. After finding that the heterologous sigma factors were capable of restoring the viability of E. coli 285c at 42 C through growth kinetics studies, the transcriptional responses of 285c to an extended heat shock in the presence of Sigma70-Lb and Sigma70-Lp were found to be similar to previous studies. These results indicate the Sigma70-Lb and Sigma70-Lp are capable of initiating transcription in a complex with the E. coli 285c RNA polymerase to a sufficient degree to restore viability at elevated temperatures without triggering unusual modifications to the native transcriptional program. These heterologous sigma factors may therefore be useful to improve biochemical knowledge of the sigma factor family or for use in transcriptional engineering.
Project description:Housekeeping sigma factors in the Sigma70 family, as components of the RNA polymerase holoenzyme, are responsible for regulating transcription of genes related to vegetative growth. While these factors are well understood in model organisms such as Escherchia coli and Bacillus subtilis, little experimental work has focused on the sigma factors in members of the Lactobacillus genus such as Lactobacillus brevis and Lactobacillus plantarum. This study evaluates the ability of putative Sigma70 proteins from L. brevis (Sigma70-Lb) and L. plantarum (Sigma70-Lp) to complement a temperature sensitive mutation in E. coli 285c Sigma70. After finding that the heterologous sigma factors were capable of restoring the viability of E. coli 285c at 42 C through growth kinetics studies, the transcriptional responses of 285c to an extended heat shock in the presence of Sigma70-Lb and Sigma70-Lp were found to be similar to previous studies. These results indicate the Sigma70-Lb and Sigma70-Lp are capable of initiating transcription in a complex with the E. coli 285c RNA polymerase to a sufficient degree to restore viability at elevated temperatures without triggering unusual modifications to the native transcriptional program. These heterologous sigma factors may therefore be useful to improve biochemical knowledge of the sigma factor family or for use in transcriptional engineering. 3 biological replicates per sigma factor
Project description:In this study, we examined Caco-2 cell gene expression after infection with E. coli (Ec), Lactobacillus plantarum (Lp) and the combination of the two (mix) Keywords: Lactobacillus plantarum and E. coli influences on Caco2 cells gene expression
Project description:In this study, we examined Caco-2 cell gene expression after infection with E. coli (Ec), Lactobacillus plantarum (Lp) and the combination of the two (mix) Cells were washed in PBS and re-fed with experimental DMEM without serum or antibiotics before the experiments. Caco-2 cells were infected with E. coli (10 9 CFU/ml at 1:10 multiplicity ratio), and/or L. plantarum (1010 CFU/ml, 1:100 multiplicity ratio), and incubated for 2 hr
Project description:We successfully isolated an E. coli strain harboring rpoD mutant B8 with 2% (v/v) butanol tolerance using global transcriptional machinery engineering approach. DNA microarrays were employed to assess the transcriptome profile of n-butanol tolerance strain B8 and control strain E. coli JM109. The goal of this study is therefore to identify E. coli genes that are involved in n-butanol tolerance.
Project description:Comparison of Escherichia coli proteomics of different DNA sequence binding proteins and identification of heterologous expressed protein
Project description:LF82, an adherent invasive Escherichia coli (AIEC) pathobiont, is associated with Crohn’s disease, an inflammatory bowel disease of unknown etiology. No genetic features have been identified that distinguish AIEC strains, such as LF82, from “commensal” or pathogenic E. coli. We investigated an extremely rare single nucleotide polymorphism (SNP) within the highly conserved rpoD gene, encoding sigma70 [primary sigma factor, RNA polymerase (RNAP)]. We demonstrate that sigma70 D445V results in transcriptome and phenotypic changes consistent with LF82 phenotypes, including increased biofilm formation and antibiotic resistance. The position of D445V within RNAP is predicted to affect spacer interaction; in vitro transcriptions reveal that the variant increases transcription from several promoters with a 16 bp spacer and a -14G:C. Our work demonstrates that a single SNP within the bacterial primary sigma can lead to myriad gene expression changes/ new phenotypes and suggests an underrecognized mechanism by which pathobionts and other strain variants can emerge.
Project description:Heterologous gene expression to expand the native genetic capability of E. coli is the backbone of protein expression and metabolic engineering. The goal of this study was to determine how the identity of the heterologous gene expressed affected the host cell transcriptome. We generated a library of E. coli expressing 46 heterologous genes through an identical rhamnose inducible expression system and perform high throughput ribosome profiling.
