Project description:Several genome-wide transcriptome analyses that focused on p53-induced cellular responses in many cellular contexts have continued to expand the already vast p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses we performed translatome analysis by polysomal profiling on MCF7 cells treated with Doxorubicin and Nutlin-3a. A comparison between the transcriptome and the translatome revealed a large number of uncoupled genes, whose transcription changes did not correlate with translation changes. Overall, we establish p53 as a master regulator of translational control and identify many p53 target genes affecting translation that can contribute to p53-dependent cellular responses. Keywords: p53, transcriptome, translatome, polysomal RNA, subpolysomal RNA, uncoupling, Doxorubicin, Nutlin-3a Total RNA (tot) was extracted from MCF7 vector cells after 16h of treatment with Doxorubicin (1.5uM) and Nutlin-3a (10uM) or DMSO (solvent, as control treatment). Polysomal profiling was performed after the same conditions. We collected all subpolysomal mRNA fractions (sub) and the polysomal ones (pol) after sucrose gradient fractionation of cytoplasmic lysates to analyze separately mRNAs that are not actively translated from those that are considered in active translation, respectively. Experiments were performed in three biological replicates.
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor. The comparison between transcriptional and polysomal profiling was used for the discovery of general and mRNA-specific changes in the translation state of the serum starved MCF7 cells transcriptome in response to E2 stimulus. To identify translationally regulated mRNA molecules, gene expression signals derived from the polysomal populations were compared by microarrays analysis to those obtained from unfractionated total RNAs. Polysomal RNA and total RNA were isolated from MCF7 cells serum starved and treated with E2. Cells lysates were collected before (t = 0 min) and after (t = 60 min) E2 treatment. All experiments were run in quadruplicates.
Project description:We subjected MCF7 cells to starvation with 0.5% charcoal treated serum for 48h and then we added 17-beta estradiol (E2) at final concentration of 10 nM, profiling before and after 60 minutes of treatment the transcriptome and the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation. Comparison of translatome profile changes with corresponding transcriptome profile changes represents a way of studying translational control networks and the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. It is well known that E2 is a strong transcriptional regulator, while its translational control activity is less characterized. To provide a direct experimental evaluation of E2 induced translational regulation, we compared translatome and transcriptome profiles of E2 treated cells. Keywords: polysomal profiling, translatome profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, estradiol stimulation, estrogen receptor.
Project description:Several genome-wide transcriptome analyses that focused on p53-induced cellular responses in many cellular contexts have continued to expand the already vast p53-regulated transcriptional networks. To investigate post-transcriptional controls as an additional dimension of p53-directed gene expression responses we performed translatome analysis by polysomal profiling on MCF7 cells treated with Doxorubicin and Nutlin-3a. A comparison between the transcriptome and the translatome revealed a large number of uncoupled genes, whose transcription changes did not correlate with translation changes. Overall, we establish p53 as a master regulator of translational control and identify many p53 target genes affecting translation that can contribute to p53-dependent cellular responses. Keywords: p53, transcriptome, translatome, polysomal RNA, subpolysomal RNA, uncoupling, Doxorubicin, Nutlin-3a
Project description:We developed RiboLace, a novel method based on a new puromycin-containing molecule, for the isolation of active ribosomes and associate RNAs by means of an antibody-free and tag-free pull-down approach. RiboLace is fast, it works with very low input material and can be easily and rapidly used to obtain a transcriptome-wide snapshot of active translation from eukaryotic in vitro and in vivo systems. Keywords: translation, RiboLace, polysome profiling, RNA-seq, POL-seq, active translation
Project description:To identify which genes were regulated by mRNA helicase activity, the effect of eIF4A1 knockdown on the MCF7 cell transcriptome and translatome was determined. eIF4A1-dependent mRNAs were highly enriched for several classes of genes with oncogenic potential, which leads to a model whereby dysregulation of mRNA unwinding contribues to the malignant phenotype in breast cancer cells via preferential translation of a subset of genes.
Project description:To identify which genes were regulated by mRNA helicase activity, the effect of eIF4A1 knockdown on the MCF7 cell transcriptome and translatome was determined. eIF4A1-dependent mRNAs were highly enriched for several classes of genes with oncogenic potential, which leads to a model whereby dysregulation of mRNA unwinding contribues to the malignant phenotype in breast cancer cells via preferential translation of a subset of genes.
Project description:This experiment performed RNA-seq of transcriptome and translatome (translating mRNA) of Caco-2 cells We extracted transcriptome and translatome from Caco-2 cells and deep sequenced them
Project description:We examined the possible effects of hypertonic stress on Arabidopsis translatome using polysome profiling. We found that the translatome is partly and rapidly reprogrammed in response to hypertonic stress, and such translatome reprogramming is DCP5-dependent.
Project description:Translatome analysis by sucrose gradient centrifugation of cell lysates followed by microarray profiling of the polysomal and subpolysomal RNA fractions represents a way of both studying translational control networks and better approximating the proteomic representation of cells. It is an established notion that translational control takes place essentially at the translation initiation level, therefore the variation in abundance of a given mRNA species on polysomes can be directly related to the variation in abundance of the corresponding protein. Comparison of translatome profile changes with corresponding transcriptome profile changes can provide a measure of the degree of concordance between cellular controls affecting mRNA abundance and cellular controls affecting mRNA availability to translation. To provide a direct experimental evaluation of the phenomenon, we decided to study a classical example of transcriptional reprogramming of gene expression: Epidermal Growth Factor (EGF) treatment. This stimulus triggers a well known chain of intracellular transduction events, ultimately resulting in a multifaceted phenotypic spectrum of changes with prevalent induction of cell growth and proliferation. We subjected HeLa cells to serum starvation for 12h and then we added EGF at final concentration of 1 μg/ml, profiling before and after 40 minutes of treatment the transcriptome, the translatome, coming from the polysomal pool of mRNAs after sucrose gradient separation, and also the mRNA content of the subpolysomal pool, expected not to be actively translated. Keywords: translatome profiling, polysomal profiling, polysomal RNA, translational control, translational profiling, polysome profiling, post-transcriptional regulation, EGF starvation release.