629 research outputs found
Lessons from the functional characterization of lncRNAs: introduction to mammalian genome special issue.
Identification of antisense long noncoding RNAs that function as SINEUPs in human cells
Mammalian genomes encode numerous natural antisense long noncoding RNAs (lncRNAs) that regulate gene expression. Recently, an antisense lncRNA to mouse Ubiquitin carboxyl-terminal hydrolase L1 (Uchl1) was reported to increase UCHL1 protein synthesis, representing a new functional class of lncRNAs, designated as SINEUPs, for SINE element-containing translation UP-regulators. Here, we show that an antisense lncRNA to the human protein phosphatase 1 regulatory subunit 12A (PPP1R12A), named as R12A-AS1, which overlaps with the 5' UTR and first coding exon of the PPP1R12A mRNA, functions as a SINEUP, increasing PPP1R12A protein translation in human cells. The SINEUP activity depends on the aforementioned sense-antisense interaction and a free right Alu monomer repeat element at the 3' end of R12A-AS1. In addition, we identify another human antisense lncRNA with SINEUP activity. Our results demonstrate for the first time that human natural antisense lncRNAs can up-regulate protein translation, suggesting that endogenous SINEUPs may be widespread and present in many mammalian species
Simplified ontologies allowing comparison of developmental mammalian gene expression
The Developmental eVOC ontologies presented are simplified orthogonal ontologies describing the temporal and spatial distribution of developmental human and mouse anatomy
A code for transcription initiation in mammalian genomes
Genome-wide detection of transcription start sites (TSSs) has revealed that RNA Polymerase II transcription initiates at millions of positions in mammalian genomes. Most core promoters do not have a single TSS, but an array of closely located TSSs with different rates of initiation. As a rule, genes have more than one such core promoter; however, defining the boundaries between core promoters is not trivial. These discoveries prompt a re-evaluation of our models for transcription initiation. We describe a new framework for understanding the organization of transcription initiation. We show that initiation events are clustered on the chromosomes at multiple scales-clusters within clusters-indicating multiple regulatory processes. Within the smallest of such clusters, which can be interpreted as core promoters, the local DNA sequence predicts the relative transcription start usage of each nucleotide with a remarkable 91% accuracy, implying the existence of a DNA code that determines TSS selection. Conversely, the total expression strength of such clusters is only partially determined by the local DNA sequence. Thus, the overall control of transcription can be understood as a combination of large- and small-scale effects; the selection of transcription start sites is largely governed by the local DNA sequence, whereas the transcriptional activity of a locus is regulated at a different level; it is affected by distal features or events such as enhancers and chromatin remodeling
CAGE-TSSchip: promoter-based expression profiling using the 5'-leading label of capped transcripts
A novel approach that combines CAGE expression analysis with oligonucleotide array technology allows for the accurate and sensitive detection of promoter-based transcriptional activity
piRNAs Warrant Investigation in Rett Syndrome: An Omics Perspective
Mutations in the MECP2 gene are found in a large proportion of girls with Rett Syndrome. Despite extensive research, the principal role of MeCP2 protein remains elusive. Is MeCP2 a regulator of genes, acting in concert with co-activators and co-repressors, predominantly as an activator of target genes or is it a methyl CpG binding protein acting globally to change the chromatin state and to supress transcription from repeat elements? If MeCP2 has no specific targets in the genome, what causes the differential expression of specific genes in the Mecp2 knockout mouse brain? We discuss the discrepancies in current data and propose a hypothesis to reconcile some differences in the two viewpoints. Since transcripts from repeat elements contribute to piRNA biogenesis, we propose that piRNA levels may be higher in the absence of MeCP2 and that increased piRNA levels may contribute to the mis-regulation of some genes seen in the Mecp2 knockout mouse brain. We provide preliminary data showing an increase in piRNAs in the Mecp2 knockout mouse cerebellum. Our investigation suggests that global piRNA levels may be elevated in the Mecp2 knockout mouse cerebellum and strongly supports further investigation of piRNAs in Rett syndrome.</jats:p
Synthetic in vitro transcribed lncRNAs (SINEUPs) with chemical modifications enhance target mRNA translation.
Chemically modified mRNAs are extensively studied with a view toward their clinical application. In particular, long noncoding RNAs (lncRNAs) containing SINE elements, which enhance the translation of their target mRNAs (i.e., SINEUPs), have potential as RNA therapies for various diseases, such as haploinsufficiencies. To establish a SINEUPâbased system for efficient protein expression, we directly transfected chemically modified in vitro transcribed (mIVT) SINEUP RNAs to examine their effects on target mRNA translation. mIVT SINEUP RNAs enhanced translation of EGFP mRNA and endogenous target Sox9 mRNA in both cultured cells and a cellâfree translation system. Our findings reveal the functional role of RNA modifications in SINEUPs and suggest several broad clinical applications of such an RNA regulatory system
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