Project description:Polyadenylation controls mRNA biogenesis, nuclear export, translation, and decay. These processes are interdependent and coordinately regulated by several poly(A)-binding proteins (PABPs). How PABPs are functionally regulated to control RNA fate is not fully understood. Here, we show that human PABPN1, the nuclear PABP, is phosphorylated by mitotic kinases at four specific sites during mitosis when nucleoplasm and cytoplasm mix. We employed long-read sequencing to detect altered activities of PABPN1 mutants on poly(A) tails lengths of individual mRNAs and TimeLapse-seq to monitor mRNA turnover rates. Phospho-inhibitory PABPN1 mutants lengthened poly(A) tails on both spliced and unspliced transcripts, increased mRNA half-lives and decreased synthesis, and blocked cell proliferation. Although phospho-mimetic PABPN1 mutants still bind RNA, poly(A) tails were shorter in vivo. Thus, PABPN1 phosphorylation reduces the polyadenylation activity of PABPN1 and increases mRNA instability. We conclude that PABPN1 regulation balances mRNA synthesis and decay during cell cycle to achieve transcriptome homeostasis.
Project description:Oxidative stress plays a pivotal role in age-related diseases, including oxidative aging, by promoting cellular damage and dysfunction.
Project description:The goal of this study is to get the profile of the OVA-treated MutuDC transcriptome. Based on the dada of transcriptome, we processed our sgRNA sequencing data of genome-wide CRISPR/Cas9 screening. Briefly, after we have obtained the enriched gene list from our sgRNA sequencing, we excluded the genes undetected in OVA-treated MutuDC transcriptome to further refine our screening gene list.
Project description:Deregulated gene expression is a hallmark of cancer, however most studies to date have analyzed short-read RNA-sequencing data with inherent limitations. Here, we combine PacBio long-read isoform sequencing (Iso-Seq) and Illumina paired-end short read RNA sequencing to comprehensively survey the transcriptome of gastric cancer (GC), a leading cause of global cancer mortality. We performed full-length transcriptome analysis across 10 GC cell lines covering four major GC molecular subtypes (chromosomal unstable, Epstein-Barr positive, genome stable and microsatellite unstable). We identify 60,239 non-redundant full-length transcripts, of which >66% are novel compared to current transcriptome databases. Novel isoforms are more likely to be cell-line and subtype specific, expressed at lower levels with larger number of exons, with longer isoform/coding sequence lengths. Most novel isoforms utilize an alternate first exon, and compared to other alternative splicing categories are expressed at higher levels and exhibit higher variability. Collectively, we observe alternate promoter usage in 25% of detected genes, with the majority (84.2%) of known/novel promoter pairs exhibiting potential changes in their coding sequences. Mapping these alternate promoters to TCGA GC samples, we identify several cancer-associated isoforms, including novel variants of oncogenes. Tumor-specific transcript isoforms tend to alter protein coding sequences to a larger extent than other isoforms. Analysis of outcome data suggests that novel isoforms may impart additional prognostic information. Our results provide a rich resource of full-length transcriptome data for deeper studies of GC and other gastrointestinal malignancies.
Project description:The breast cancer screening population was selected for small RNA sequencing of plasma exosomes, one of several types of extracellular vesicles. The analysis included 728 piRNAs, 2656 miRNAs, and 154 tsRNAs.