Project description:Unlike the characterised histone proteins of a number of methanogenic and themophilic archaea, previous research indicated that HpyA, the sole histone encoded in the model halophile Halobacterium salinarum, is not involved in DNA packaging. Instead, it was found to have widespread but subtle effects on gene expression, and affect cell morphology. Here we report that HpyA is important for growth in reduced salinity and regulates gene expression of ion uptake and nucleotide metabolism pathways in a salt-dependent manner. Analysis of the genome-wide binding pattern of HpyA reveals that its binding is dependent on external salt concentration as well as growth phase. Combining the transcriptomic and ChIP-Seq data suggests a role for HpyA as a regulator of the expression of ion uptake genes as well as a co-regulator of other genes of diverse functions in a salt-dependent manner. In this GEO series , we use ChIP-Seq to study the genome-wide binding of HpyA-HA in optimal (4.2M NaCl) and reduced (3.4M) in exponential and stationary phase, using HA-tag-allone strains as a control
Project description:We set out to determine a) if histone in Halobacterium salinarum regulates transcription and b) whether the magnitude and extent of these changes matches those observed in organisms which use histone protein as their primary DNA packaging agent. To this end, gene expression data for a histone knock-out (Δura3ΔhpyA) strain versus parent (Δura3) were collected.
Project description:Unlike the characterised histone proteins of a number of methanogenic and themophilic archaea, previous research indicated that HpyA, the sole histone encoded in the model halophile Halobacterium salinarum, is not involved in DNA packaging. Instead, it was found to have widespread but subtle effects on gene expression, and affect cell morphology. Here we report that HpyA is important for growth in reduced salinity and regulates gene expression of ion uptake and nucleotide metabolism pathways in a salt-dependent manner. Analysis of the genome-wide binding pattern of HpyA reveals that its binding is dependent on external salt concentration as well as growth phase. Combining the transcriptomic and ChIP-Seq data suggests a role for HpyA as a regulator of the expression of ion uptake genes as well as a co-regulator of other genes of diverse functions in a salt-dependent manner. In this GEO series , we use RNA-Seq to study the transcriptonal effect of HpyA in optimal (4.2M NaCl) and reduced (3.4M) during exponential growth phase.
Project description:We set out to determine a) if histone in Halobacterium salinarum regulates transcription and b) whether the magnitude and extent of these changes matches those observed in organisms which use histone protein as their primary DNA packaging agent. To this end, gene expression data for a histone knock-out (?ura3?hpyA) strain versus parent (?ura3) were collected. The histone deletion mutant and parent strain, at log and stationary phase, were compared to the common reference strain NRC-1 (log). There are three biological replicates each, plus dye-flips, for a total of 24 arrays
Project description:Halobacterium salinarum NRC-1 was grown in CM media, at 37oC in a waterbath with agitation of 125 rpm under constant light. Analysis of transcriptional changes during growth, in addition to mapping of transcriptome structure under the same conditions, provided interesting insights about regulatory logic within prokaryotic coding regions.