Project description:Nitric oxide being a versatile molecule inside biological systems, from being both a cell signaling molecule to a potent stress agent, has significant effect in the transcriptional response in fission yeast. We have used fission yeast microarrays to identify cellular targets of Nitric Oxide (NO) and to further understand the cellular mechanism of NO action. We report the change in the global gene expression profile response to NO in S. pombe cells
Project description:Nitric oxide being a versatile molecule inside biological systems, from being both a cell signaling molecule to a potent stress agent, has significant effect in the transcriptional response in fission yeast. We have used fission yeast microarrays to identify cellular targets of Nitric Oxide (NO) and to further understand the cellular mechanism of NO action. We report the change in the global gene expression profile response to NO in S. pombe cells S. pombe cells were treated with pure NO donor compond detaNONOate for 15 minutes at 30 degrees celcius for both the wild type and pap1 deleted strain, the cells were processed through RNA extraction and hybridization on Affymetrix microarrays. We included pap1 deleted strain of S. pombe alongside wild type strain as we earlier reported that pap1 is important to combat nitrosative stress, so pap1 might control the expression of several genes under nitrosative stress. Wild type control and treated samples as well as Mutant control and treated sets are included in 2 biological replicates for each.
Project description:In examining NO signaling in the fission yeast Schizosaccharomyces pombe, we found that the putative NO dioxygenase SPAC869.02c (named Yhb1) and the S-nitrosoglutathione reductase Fmd2 cooperatively reduced intracellular NO levels as NO-detoxification enzymes. Although both protein levels were increased with exogenous NO, their expression patterns were different during growth phases. While expression of Yhb1 in the log phase was abrogated by treatment with an NO synthase inhibitor, induction of Fmd2 in the stationary phase was correlated with elevated mitochondrial respiratory chain (MRC) activity and reactive oxygen species (ROS) generation. Moreover, NO was localized in the mitochondria specifically in the stationary phase, suggesting that there are at least two distinctive types of NO signaling in S. pombe cells. For mitochondrial NO signaling, pretreatment with an NO donor effectively rescued the cell viability by repressing generation of ROS under oxidative stress. DNA microarray analysis revealed that exogenous NO contributes to tolerance to hydrogen peroxide (H2O2) stress by (i) inhibition of Fe3+ to Fe2+conversion, (ii) upregulation of the H2O2-detoxifying enzymes, and (iii) downregulation of the MRC genes. Therefore, NO is suggested to play a pivotal role in the negative feedback system to regulate ROS levels under oxidative stress in S. pombe cells.
Project description:Expression profiles of polg mutant cells reveal that many genes encoding proteins involved in cell wall biogenesis and stress response are induced, suggesting that polg mutant cells attempt to maintain growth potential and undergo extensive oxidative metabolism. Conversely, many genes encoding proteins involved in ribosome biogenesis and respiration are repressed, indicating that cells depleted of mtDNA are adapted to grow slowly in absence of mitochondrial function. Keywords: Schizosaccharomyces pombe ployg mutant cells vs wild type cells.