Project description:Nonsense mediated mRNA decay (NMD) is a translation-dependent surveillance pathway that eliminates RNAs with short open reading frames (ORFs) and long 3' untranslated regions (UTRs). Upf1 is the key protein of this degradation pathway and we were interested to purify the associated RNAs. Moreover we have done purifications of two proteins from the general mRNA turnover in yeast : Pab1 and Lsm1 that both bind RNAs poly(A) tails. We have also done a purification with a protein from the small ribosomal subunit (40S) in order to have a look at the translated RNAs.
Project description:Encoded model contains complete kinetics of infection for coxsackievirus B3 (CVB3), a compact and fast-acting RNA virus. The model consists of separable, detailed modules describing viral binding-delivery, translation-replication, and encapsidation. Specific module activities are dampened by the type I interferon response to viral double-stranded RNAs (dsRNAs), which is itself disrupted by viral proteinases
Project description:Adenovirus is a common human pathogen that relies on host cell processes for transcription and processing of viral RNA and protein production. Although adenoviral promoters, splice junctions, and cleavage and polyadenylation sites have been characterized using low-throughput biochemical techniques or short read cDNA-based sequencing, these technologies do not fully capture the complexity of the adenoviral transcriptome. By combining Illumina short-read and nanopore long-read direct RNA sequencing approaches, we mapped transcription start sites and cleavage and polyadenylation sites across the adenovirus genome. In addition to confirming the known canonical viral early and late RNA cassettes, our analysis of splice junctions within long RNA reads revealed an additional 35 novel viral transcripts. These RNAs include fourteen new splice junctions which lead to expression of canonical open reading frames (ORF), six novel ORF-containing transcripts, and fifteen transcripts encoding for messages that potentially alter protein functions through truncations or fusion of canonical ORFs. In addition, we also detect RNAs that bypass canonical cleavage sites and generate potential chimeric proteins by linking separate gene transcription units. Of these, an evolutionary conserved protein was detected containing the N-terminus of E4orf6 fused to the downstream DBP/E2A ORF. Loss of this novel protein, E4orf6/DBP, was associated with aberrant viral replication center morphology and poor viral spread. Our work highlights how long-read sequencing technologies can reveal further complexity within viral transcriptomes.
Project description:This experiment was to have a look at the transcriptional profiles from subjects with and without asthma following viral challenge, using Polyinosinic:polycytidylic acid (Poly IC) which is a synthetic analog of double-stranded RNA (dsRNA), a molecular pattern associated with viral infection.
Project description:We sequenced Endogenous short RNAs in Mucor circinelloides fungus grown in standard liquid culture. Short RNAs were profiled in wild type, Dicer-like 1 mutant (dcl1-), Dicer-like 2 mutant (dcl2-) and double Dicer mutant (dcl1-/dcl2-) strains. We identified many loci that produced less short RNAs in the dcl2- strain suggesting that DCL2 is the major protein generating short RNAs in Mucor circinelloides.
Project description:The accurate determination of the risk of cancer recurrence is an important unmet need in the management of prostate cancer. Patients and physicians must weigh the benefits of currently available therapies against the potential morbidity of these treatments. Herein we describe the development of a gene expression-based continuous risk index and a validation of this test in an independent, blinded cohort of post-radical prostatectomy (RP) patients. A gene expression signature, prognostic for prostate-specific antigen (PSA) recurrence, was identified through a bioinformatic analysis of the expression of 1,536 genes in malignant prostate tissue from a training cohort of consecutive patients treated with RP. The assay was transferred to a real-time RT-PCR platform, and a continuous risk index model was constructed based on the expression of 32 genes. This 32-gene risk index model was validated in an independent, blinded cohort of 270 RP patients. In multivariate analyses, the risk index was prognostic for risk of PSA recurrence and had added value over standard prognostic markers such as Gleason score, pathologic tumor stage, surgical margin status, and presurgery PSA (hazard ratio, 4.05; 95% confidence interval, 1.50-10.94; P = 0.0057). Furthermore, RP patients could be stratified based on the risk of PSA recurrence and the development of metastatic disease. The 32-gene signature identified here is a robust prognostic marker for disease recurrence. This assay may aid in postoperative treatment selection and has the potential to impact decision making at the biopsy stage.
Project description:Recent evidence indicates that codon usage bias regulates gene expression. How viruses, such as the emerging mosquito-borne Chikungunya virus (CHIKV), express their genomes at high levels despite an enrichment in rare codons remains a puzzling question. Using ribosome footprinting, here we analysed translational changes that occur upon CHIKV infection at the ER and the cytosol. We show that CHIKV infection induces codon-specific reprogramming of the host translation machinery to favor the translation of viral RNA genomes over host mRNAs with an otherwise optimal codon usage. This reprogramming was mostly apparent at the ER, where CHIKV RNAs are efficiently translated. Mechanistically, it involves CHIKV-induced overexpression of KIAA1456, an enzyme that modifies the wobble U34 position in the anticodon of tRNAs, which we find is required for proper decoding of codons that are highly enriched in CHIKV RNAs. Our findings demonstrate an unprecedented interplay of viruses with the host tRNA epitranscriptome to adapt the host translation machinery to viral production.