Project description:Ribosome profiling was used to investigate how Schizosaccharomcyes pombe cells modulate gene expression in response to cadmium exposure
Project description:Inducible MYCN-knockdown, followed by RNA-seq analysis in the MYCN-amplified neuroblastoma cell line IMR5-75, reveals profound time-dependent transcriptome changes. For modulation of MYCN levels, stable neuroblastoma cell models were used where MYCN can be downregulated via vector-based hairpin RNA induction upon addition of 1µg/ml tetracycline (IMR5-75-shMYCN. From cells treated either with tetracycline or solvent (ethanol), RNA was isolated at time points 6 hours, 12 hours and 24 hours. Experiments were done in duplicates. RNA was sequenced.
Project description:Poly(A) tails are critical for mRNA stability and translation. However, recent studies have challenged this view, showing that poly(A) tail length and translation efficiency are decoupled in non-embryonic cells. Using TAIL-seq and ribosome profiling, we investigate poly(A) tail dynamics and translational control in the somatic cell cycle. We find dramatic changes in poly(A) tail lengths of cell cycle regulatory genes like CDK1, TOP2A, and FBXO5, explaining their translational repression in M phase. We also find that poly(A) tail length is coupled to translation when the poly(A) tail is <20 nucleotides. However, as most genes have >20 nucleotide poly(A) tails, their translation is regulated mainly via poly(A) tail length-independent mechanisms during the cell cycle. Specifically, we find that terminal oligopyrimidine (TOP) tract-containing transcripts escape global translational suppression in M phase and are actively translated. Our quantitative and comprehensive data provide a revised view of translational control in the somatic cell cycle. HeLa cells were synchronized at S or M phase, and subject to RNA-seq, ribosome profiling and TAIL-seq analysis.
Project description:Ribosome profiling was used to investigate how Schizosaccharomcyes pombe cells modulate gene expression in response to osmotic shock
Project description:Ribosome profiling was used to investigate how Schizosaccharomcyes pombe cells modulate gene expression in response to hydrogen peroxide
Project description:Ribosome profiling was used to investigate how Schizosaccharomcyes pombe cells modulate gene expression in response to methyl methanesulfonate (MMS)
Project description:Transcriptional memory is critical for the faster reactivation of necessary genes upon environmental changes and requires that the genes were previously in an active state. However, whether transcriptional repression also displays “memory” of the prior transcriptionally inactive state remains unknown. In this study, we show that transcriptional repression of approximately 540 genes in yeast occurs much more rapidly if the genes have been previously repressed during carbon source shifts. This novel transcriptional response has been termed transcriptional repression memory(TREM). Interestingly, Rpd3L histone deacetylase (HDAC), targeted to active promoters induces TREM. Mutants for Rpd3L exhibit increased acetylation at active promoters and delay TREM and RNA PolII dissociation significantly. Surprisingly, the interaction between H3K4me3 and Rpd3L via the Pho23 PHD finger is sufficient to induce histone deacetylation and TREM by Rpd3L. Therefore, we propose that an active mark, H3K4me3 enriched at promoters, instructs Rpd3L HDAC to induce histone deacetylation and TREM.