Project description:RNAseq was performed in siJARID2 and control siRNA-treated human adipose tissue derived stem cells (hASC). The tretment of siRNA was performed by electroporation one day before induction of differentiation in vitro. The cells were lyzed and RNA was purified on day 6 (mid differentiation) and day 13 (full differentiation) from differentiation start.
Project description:Purpose: Identify genes regulated by ALOX15 in A549 cells that were treated with +/- IL4 and +/- ALOX15 siRNA by Next-gen sequencing
Project description:The therapeutic promise of protein-coding genetic medicines depends on accurate translation of designed nucleic acid sequences into functional proteins. Here we reveal that current design practices systematically deplete stop codons from alternative reading frames, creating an unrecognized risk of out-of-frame translation product accumulation. Using quantitative dual-fluorescence reporters, we demonstrate that out-of-frame product accumulation correlates with expression level and that stop codons serve as molecular checkpoints against aberrant translation. Genome-wide analysis shows that natural coding sequences maintain dense stop codon distributions in alternative frames—a safeguard strikingly absent from therapeutic constructs. Analysis of 120 therapeutic sequences, including FDA-approved COVID-19 mRNA vaccines, shows severe stop codon depletion: -1 frame products average 164 amino acids, six-fold longer than in natural human genes. This depletion arises because codon optimization algorithms exclude uridine from third codon positions, thereby preventing -1 frame stop codon formation. We establish stop codon-walking as a method for mapping out-of-frame translation hotspots and develop evolutionary-guided codon optimization that strategically restores stop codons through synonymous substitutions. Mass spectrometry confirms that stop codon restoration eliminates detectable out-of-frame products while preserving intended protein sequences. These findings expose a fundamental design oversight and establish principles for engineering translation fidelity into protein-coding genetic medicines.
Project description:Purpose: Identify genes regulated by ALOX15 in Normal human bronchial epithelial (NHBE) cells that were treated with +/- IL4 and +/- ALOX15 siRNA by Next-gen sequencing
Project description:UPF3A and UPF3B are paralogous genes in human cells that are involved in the nonsense-mediated decay (NMD) pathway. NMD is a cellular quality control mechanism that monitors mRNAs during translation. Aberrant translation due to features such as the presence of a premature stop codon downstream on an exon-exon junction activates NMD and leads to the degradation of the mRNA. To investigate the role of UPF3B and UPF3A in NMD, we have generated UPF3B knockout human Flp-In T-REx 293 cells using CRISPR-Cas9. We generated RNA-Sequencing data for wildtype and UPF3B KO cells with additional siRNA-mediated knockdown of Luciferase (Luc) as control or UPF3A.
Project description:In order to systematically assess the frequency and origin of stop codon recoding events, we designed a library of reporters. We introduced premature stop codons into mScarlet that enabled high-throughput quantification of protein synthesis termination errors in E. coli using fluorescent microscopy. We found that under stress conditions, stop codon recoding may occur with a rate as high as 80%, depending on the nucleotide context, suggesting that evolution frequently samples stop codon recoding events. The analysis of selected reporters by mass spectrometry and RNA-seq showed that not only translation but also transcription errors contribute to stop codon recoding. The RNA polymerase is more likely to misincorporate a nucleotide at premature stop codons. Proteome-wide detection of stop codon recoding by mass spectrometry revealed that temperature regulates the expression of cryptic sequences generated by stop codon recoding in E. coli. Overall, our findings suggest that the environment influences the accuracy of protein production which increases protein heterogeneity when the organisms need to adapt to new conditions.
Project description:A ELMSeq reporter cassette was created to monitor Dam levels by methylation, and introduced in the genome. The regions of 6 nt upstream and 6 nt downstream the stop codon were randomized to study their effect on gene expression. The ELMSeq reporter cassette was composed of: promoter - dam - random N6 - stop codon TAA - random N6 - spacer - 4xGATC. The amplicon was spanning the C-terminal region. The cassette was introduced in Mycoplasma pneumoniae.
Project description:UPF3A and UPF3B are paralogous genes in human cells that are involved in the nonsense-mediated decay (NMD) pathway. NMD is a cellular quality control mechanism that monitors mRNAs during translation. Aberrant translation due to features such as the presence of a premature stop codon downstream on an exon-exon junction activates NMD and leads to the degradation of the mRNA. To investigate the role of UPF3B and UPF3A in NMD, we have generated UPF3B knockout (KO) and UPF3A-UPF3B double KO (dKO) human Flp-In T-REx 293 cells using CRISPR-Cas9. We generated RNA-Sequencing data for wildtype, UPF3B KO and UPF3A-UPF3B dKO cells with additional siRNA-mediated knockdown of Luciferase (Luc) as control or UPF3B.
Project description:Stop codon recoding events give rise to longer proteins, which may alter the proteins function and thereby generate short-lasting phenotypic variability from a single gene.
In order to systematically assess the frequency and origin of recoding events, we designed a library of reporters. We introduced premature stop codons into mScarlet that enabled high-throughput quantification of protein synthesis termination errors in E.coli using fluorescent microscopy. We found that under stress conditions, stop codon recoding may occur as high as 80 percent of the time, depending on the genetic context, suggesting that evolution frequently samples stop codon recoding events. Targeted mass spectrometry and RNA-seq analyses showed that not only translational but also transcriptional errors contribute to stop codon recoding. The RNA polymerase is more likely to misincorporate a nucleotide at premature stop codons. Proteome-wide mass -spectrometry revealed that temperature regulates the expression of cryptic peptides generated by stop codon recoding in E.coli.
Overall, our findings suggest that the environment influences the accuracy of protein production which increases protein heterogeneity when the organisms need to adapt to new conditions.
