Project description:The hst3hst4 strain (FY background) has the HST3 and HST4 genes, encoding putative NAD-dependent deacetylases that regulate histone 3 K56 acetylation, deleted. Expression profiling using Affymetrix microarrays was used to assess the change in the gene expression in this strain in comparison to wild-type under normal growth conditions.
Project description:Cells respond to environmental signals by alteration of gene expression through action of transcription factors. A JmjC-domain-containing protein Rph1 belongs to the C2H2 zinc finger protein family and functions to repress transcription of PHR1 via histone demethylation. However, additional targets of Rph1 remain largely unknown. Here, we investigate the regulatory network of Rph1 by microarray analyses. More than 75% of Rph1-regulated genes showed increased expression in rph1M-NM-^T, suggesting Rph1 serves as a transcriptional repressor under physiological conditions. The binding motif of Rph1 resembling the STress Response Element (STRE) was over-represented in the promoters of Rph1-repressed genes. In addition, significant proportions of Rph1-regulated genes responded to DNA damage and environmental stress, implying a repressive role of Rph1 in the cross-protection of stress responses. We used expression microarray to identify Rph1-regulated genes and established Rph1 functioned as a transcriptional repressor to link DNA damage signaling and general stress response. We compared gene expression in wild-type and rph1-deleted strains cultured in rich medium (YPD) during exponential growth. 3 biological samples were analyzed.
Project description:Investigation of whole genome gene expression changes at short (2 hours) and extended (24 hours) timepoints in wild-type Saccharomyces cerevisiae treated with 50 μM menadione during exponential growth compared to an rph1Δ strain Transient treatment with 50 μM menadione elevates mitochondrial ROS and extends chronological lifespan in yeast. Deletion of RPH1, a H3K36me3 histone demethylase, block chronological lifespan extension. This study aimed to identify Rph1p-dependent gene expression changes induced by menadione treatment that may support chronological lifespan extension. Reference: Bonawitz, N.D., Chatenay-Lapointe, M., Wearn, C.M., and Shadel, G.S. (2008). Expression of the rDNA-encoded mitochondrial protein Tar1p is stringently controlled and responds differentially to mitochondrial respiratory demand and dysfunction. Curr Genet 54, 83-94.
