Project description:Polysome profiling experiments were carried out to identify the mRNAs that have altered the translation efficiency (counts in polysomal fraction/counts in monosomal fractions) in the presence of an oligonucleotide targeting a specific region of the ribosomal RNA, to study the implication of this region in the translation of specific mRNAs
Project description:We performed tRNAome sequencing to assess the tRNA changes of E.coli under oxidative stress. We found that the global translation inhibition is caused by global down-regulation of almost all tRNA species under oxidative stress. The translation elongation speed is resumed after the cells are fully adapted to the oxidative environment.
Project description:Gene expression is a dynamic process regulated on several layers starting with transcription, mRNA export, translation and finally, mRNA degradation. While subsequent layers heavily influence each other, it is not clear if the most extreme layers, chromatin architecture and mRNA decay are linked. Here, we show that changes in nascent transcription mediated by mutating H3K56 to alanine are buffered at a post-transcriptional level by the Pumilio protein Puf5, which stabilizes transcripts in a context-dependent manner. Depleting Puf5 in an H3K56A background leads to downregulation of its direct targets, largely consisting of ribosomal protein genes. This is followed by a decrease in translation efficiency and finally, cell cycle arrest. Importantly, we show that this phenomenon of post-transcriptional buffering is not only linked to H3K56A, but might be a more widespread phenomenon to ensure physiological mRNA levels and to maintain cellular homeostasis.
Project description:We used microarray to identify the global gene expression profile of recombinant E.coli culture expressing repeating unit of the C. difficile toxin A (rARU) C-terminal region. Controlled condition batch runs were performed with E.coli expressing rARU at both restricted and unrestricted DO conditions for collecting samples of log and late-log phases at unrestricted and restricted DO.
Project description:Gene expression regulation in eukaryotes is a multi-level process, including transcription, mRNA translation, and protein turnover. Many studies have reported the sophisticated transcriptional regulations during neural development, but the global translational dynamics is still ambiguous. Here, we differentiated human embryonic stem cells (ESCs) into neural progenitor cells (NPCs) with high efficiency and performed ribosome sequencing and RNA sequencing on both ESCs and NPCs. Data analysis revealed that translational controls engaged in many critical pathways and contributed significantly to neural fate determination regulation. Furthermore, we showed that the sequence characteristics in the untranslated region (UTR) might regulate translation efficiency. Specifically, genes with short 5UTR and intense Kozak sequence are associated with high translation efficiency in human ESCs, while genes with long 3'UTR are related to high translation efficiency in NPCs. In addition, we identified four biasedly-used codons (GAC, GAT, AGA, and AGG) and dozens of short open reading frames during neural progenitor differentiation. Thus, our study reveals the translational landscape during early human neural differentiation and provides insights into the regulation of cell fate determination at the translational level.
Project description:The Epstein-Barr virus (EBV) genome encodes several hundred transcripts. Using total RNA sequencing and ribosome profiling, we have characterized the transcriptional and translational scope of B cells infected with EBV. We could show that viral transcripts are translated at variable efficiency and that several viral genes show ribosome recruitment to the 5’ leader region of mRNAs. We used two different virus strains with differing in vitro characteristics to study EBV translation and could show that in cells infected with the weakly replicating EBV strain some lytic genes showed evidence of monosomal ribosome recruitment mainly in the 5’ leader region and on start codons in the absence of protein production. Finally, we could identify 25 novel upstream open reading frames that potentially regulate the translation efficiency of some viral genes.
Project description:Rcm1 methylates ribosomal RNA at C2278 and a knockout of this gene induces structural alterations of rRNA and decreased translational fidelity. To test the influence of rcm1 knockout on the specific translation of mRNAs, we analysed the mRNA recruitment pattern into polysomes versus total cellular mRNAs under different oxidative stress conditions by microarrays. In order to estimate the efficiency of translation of individual mRNAs, we calculated the translational efficiency (TE) as ratio between signal intensity in the polysome fraction (‘translatome’) versus signal intensity in the total yeast cell lysate (‘transcriptome’) for each probeset on the array. Genes with at least 2-fold up- or downregulation at p < 0.05 were defined to be significantly translationally up- or downregulated.
Project description:Comparison of translation efficiency in S. cerevisiae, S. paradoxus, and their F1 hybrid. SRA submission number SRP028552; BioProject number PRJNA213844; Ribosome profiling was used to compare mRNA abundance, ribosome occupancy, and translation efficiency in two yeast species and their F1 hybrid.