Project description:Loss of nutrient supply elicits alterations of the SUMO proteome and sumoylation is crucial to various cellular processes including transcription. However, the physiological significance of sumoylation of transcriptional regulators is unclear. To begin clarifying this, we mapped the SUMO proteome under nitrogen-limiting conditions in Saccharomyces cerevisiae. Interestingly, several RNA polymerase III (RNAPIII) components are major SUMO targets under normal growth conditions, including Rpc53, Rpc82, and Ret1, and nutrient starvation results in rapid desumoylation of these proteins. These findings are supported by ChIP-seq experiments that show that SUMO is highly enriched at tDNA genes. Furthermore, RNA-seq experiments revealed that preventing sumoylation results in significantly decreased tRNA transcription. TORC1 inhibition resulted in the same effect, and our data indicate that the SUMO and TORC1 pathways are both required for robust tDNA expression. Importantly, tRNA transcription was strongly reduced in cells expressing a non-sumoylatable Rpc82-4KR mutant, which correlated with a misassembled RNAPIII transcriptional complex. Our data suggest that in addition to TORC1 activity, sumoylation of RNAPIII is key to reaching full translational capacity under optimal growth conditions.
Project description:We performed transcriptome (RNA-seq) analyses for Campylobacter jejuni 11168 wild-type (WT) and Cj1608 deletion mutant (ΔCj1608::aphA-3) under oxidative stress and optimal microaerobic growth conditions. The expression of 231 genes was affected by oxidative stress in stressed wild-type cells (WTS) compared to non-stressed cells (WT). A comparison of genes expressed in the ΔCj1608 and WT strains under optimal growth conditions revealed 380 differently expressed genes. Moreover, transcriptional changes and overall final protein levels correlated across multiple genes. The data were validated through RT-qPCR and phenotype experiments for selected processes.
Project description:We performed transcriptome (RNA-seq) analyses for Arcobacter butzleri RM4018 wild-type (WT) and Abu0127 deletion mutant (ΔAbu0127::aphA-3) under oxidative stress and optimal microaerobic growth conditions. The expression of 290 genes was affected by oxidative stress in stressed wild-type cells (WTS) compared to non-stressed cells (WT). A comparison of genes expressed in the ΔAbu0127 and WT strains under optimal growth conditions revealed 779 differently expressed genes. Moreover, transcriptional changes and overall final protein levels correlated across multiple genes. The data were validated through RT-qPCR and phenotype experiments for selected processes.
Project description:We performed transcriptome (RNA-seq) analyses for Helicobacter pylori N6 wild-type (WT) and HP1021 deletion mutant (ΔHP1021::aphA-3) under oxidative stress and optimal microaerobic growth conditions. The expression of 411 genes was affected by oxidative stress in stressed wild-type cells (WTS) compared to non-stressed cells (WT). Interestingly, ΔHP1021 did not respond to oxidative stress. A comparison of genes expressed in the ΔHP1021 and WT strains under optimal growth conditions revealed 191 differently expressed genes. Moreover, transcriptional changes and overall final protein levels correlated across multiple genes. The data were validated through RT-qPCR and phenotype experiments for selected processes.
Project description:Recently a dRNA-Seq study with Haloferax volcanii has been published that led to the discovery of nearly 2800 novel transcription start sites for non-coding RNAs. However, the dRNA-Seq results are confined to the 5'-end of transcripts and does not contain any length information. Therefore, a major aim of the present RNA-Seq study was the elucidation of the lengths of the novel non-coding RNAs. A second aim was to analyze the operon structure of protein-coding genes. The recent dRNA-Seq study was confined to cultures grown under optimal conditions. It was revealed that less than half of the protein-coding genes were expressed. Therefore, the present RNA-Seq study used cultures grown under four different conditions to identify further transcripts of protein-coding genes that are not needed under optimal conditions. RNA samples from the four conditions were mixed prior to the RNA-Seq analyses (mixed RNA-Seq). The results allowed to characterize the sum of transcriptomes of H. volcanii under four conditions. Northern blot analyses were used to characterize selected examples in detail. Many important results were obtained, including the length determination of all transcripts, a genome-wide operon analysis, verification of a high fraction of antisense RNAs, and the discovery that 30% of all protein-coding transcripts have overlapping 3'-UTRs.
Project description:RNA-seq of Helicobacter pylori N6 wild-type and HP1021 deletion mutant under microaerophilic and aerobic conditions (optimal growth and oxidative stress conditions, respectively)
Project description:We performed DNA-protein interaction (ChIP-seq) analyses for Helicobacter pylori N6 wild-type (WT) and HP1021 deletion mutant (ΔHP1021::aphA-3) under oxidative stress (21% O2) and optimal microaerobic growth (5% O2) conditions. We detected 100 binding sites of HP1021 on the H. pylori N6 chromosome, most of which are promoter-located, likely affecting gene transcription. 84 of 100 identified HP1021 binding sites were located near promoter regions. EMSA and ChIP-qPCR confirmed the binding of HP1021 to the promoter region of a few genes.