Project description:To generate a bona fide model to study post-stress baterial programmed cell death (PCD), we used a temperature-sensitive E. coli mutant (dnaB-Ts) since temperature stress can be rapidly reversed while other stress, such as antibotic treatment, is difficult to be rapidly and completely stopped and removed for post-stress PCD analysis. When cells were shifted from permissive (30 °C) to non-permissive temperature (42 °C), the dnaB-Ts ΔahpC double mutant maintained full surival while survival of the dnaB-Ts single mutant dropped 3 orders of magnitude; similarly, the double mutant showed much higher survival during treatments with quinolones and β-lactams at permissive temperature. The purpose of the RNA-seq analyses is to uncover molecular mechanisms underlying the increased survival of the dnaB-Ts ΔahpC double mutant by comparing its transcriptional profiles with that of the dnaB-Ts single mutant at both permissive and non-permissive temperature. The results showed that multiple antioxidative systems and stress response pathways were highly upregulated due to a deficiency of ahpC when combined with a dnaB-Ts mutation. The high expression of these genes are consistent with the lower levels of toxic reactive oxygen species (ROS) in the dnaB-Ts ΔahpC mutant than in the dnaB-Ts single mutant. Thus, the RNA-seq data supported that ROS are an important lethal factor in bacterial suicide pathways when bacterial cells are exposed to harsh stress.
Project description:Expression analysis of Saccharomyces cerevisiae TAF5 and taf5 temperature conditional mutants grown at permissive and non-permissive temperature. Investigation of whole genome gene expression level changes in Saccharomyces cerevisae taf5-17, taf5-45, taf5-408 and taf5-10.4 mutants, compared to the wild-type strain. The mutations engineered into the strains confer temperature conditional growth. The mutants analyzed in this study are further described in Layer et. al., 2010. Direct Transactivator-Transcription Factor IID (TFIID) Contacts Drive Yeast Ribosomal Protein Gene Transcription. Journal of Biological Chemistry.
Project description:The ts-p53 E285K protein is a rare p53 mutant with temperature-sensitive (ts) loss of function characteristics. In cancer cells, which express ts-p53 E285K intriniscally, endogenous wild type p53 activity is reconstituted by appropriate cultivation temperature (permissive condition). At non-appropriate cultivation temperature (restrictive condition) this p53 mutant is inactive. The present study took advantage of this mechanism and employed IPH-926 lobular breast cancer cells and BT-474 ductal breast cancer cells, which both harbor endogenous ts-p53 E285K, for the transcriptional profiling of p53-responsive genes. This new approach eliminated the need for genetic modification or cytotoxic stimulation to achive a p53 response in the cells being investigated .
Project description:The ts-p53 E285K protein is a rare p53 mutant with temperature-sensitive (ts) loss of function characteristics. In cancer cells, which express ts-p53 E285K intrinsically, endogenous wild type p53 activity is reconstituted by appropriate cultivation temperature (permissive condition). At non-appropriate cultivation temperature (restrictive condition) this p53 mutant is inactive. The present study took advantage of this mechanism and employed IPH-926 lobular breast cancer cells and BT-474 ductal breast cancer cells, which both harbor endogenous ts-p53 E285K, for the transcriptional profiling of p53-responsive genes. This new approach eliminated the need for genetic modification or cytotoxic stimulation to achive a p53 response in the cells being investigated . Three subseqent passages of IPH-926 lobular breast cancer cells (harboring ts-p53 E285K) were seeded into two parallel culture dishes each and were allowed to adopt to restrictive and permissive condition for 24 h before analysis on Affymetrix U133 Plus 2.0 microarrays. Subsequently, this experiment was repeated with BT-474 ductal breast cancer cells (also harboring ts-p53 E285K). To gate out non-specific temperature effects, the same experiment was also performed with MCF-7 breast cancer cells (harboring wt p53). Probe sets differentially expressed at restrictive versus permissive condition in MCF-7 were considered as non-specifically regulated. These probe sets were excluded from the final statistical analysis of IPH-926 and BT-474 expression data. response to restored p53 activity
Project description:Expression analysis of Saccharomyces cerevisiae TAF5 and taf5 temperature conditional mutants grown at permissive and non-permissive temperature. Investigation of whole genome gene expression level changes in Saccharomyces cerevisae taf5-17, taf5-45, taf5-408 and taf5-10.4 mutants, compared to the wild-type strain. The mutations engineered into the strains confer temperature conditional growth. The mutants analyzed in this study are further described in Layer et. al., 2010. Direct Transactivator-Transcription Factor IID (TFIID) Contacts Drive Yeast Ribosomal Protein Gene Transcription. Journal of Biological Chemistry. A twenty chip study using total RNA recovered from four separate wild-type cultures of Saccharomyces cerevisiae and four separate cultures for each of four taf5 temperature conditional mutants (16 mutant cultures). Each chip measures the expression level of 5,777 genes from Saccharomyces S288C with eight 60-mer probe pairs (PM/MM) per gene, with three-fold technical redundancy.
Project description:Transcriptome analyses of thermosensitive exosome mutants from permissive temperature to various time exposure to restrictive temperature.
Project description:In order to assess a set of gene regulations to get the acquired thermotolerance in a comprehensive scale, we conducted a transcriptome analysis. Chinese cabbage microarray (A-MEXP-115)was used to examine the gene expression of 7-day old seedlings exposed at permissive high temperature over the time course (0, 0.25, 1, 3 and 12 hr).
Project description:The cell line PrE2.8 was cultured at a permissive growth temperature of 33oC and then half transferred to a non-permissive temperature of 39.5oC for 4days. The two sets of cells were harvested and co-hybridised to identify genes with altered expression resulting from unduced differentiation. Keywords: Induction of cellular differentiation
Project description:The gene expression profiles of a temperature-sensitive strain, ts-8, was compared agains its wild type counterpart, NC-1. Keywords: mutant comparision, two class unpaired design