Project description:Maturation of canonical microRNA (miRNA) is initiated by DROSHA that cleaves the primary transcript (pri-miRNA). Over 1,800 miRNA loci are annotated in humans, but it remains largely unknown if and at which sites the pri-miRNAs are cleaved by DROSHA. Here we performed in vitro processing on a full set of human pri-miRNAs (miRBase v21) followed by sequencing. This comprehensive profiling enabled us to classify miRNAs based on DROSHA-dependence and map their cleavage sites with respective processing efficiency measures. Only 758 pri-miRNAs are confidently processed by DROSHA, while the majority may be non-canonical or false entries. Analyses of the DROSHA-dependent pri-miRNAs show key cis-elements for processing. We observe widespread alternative processing as well as unproductive cleavage events such as “nick” or “inverse” processing. SRSF3 is a broad-acting auxiliary factor modulating alternative processing and suppressing unproductive processing. The profiling data and methods developed in this study will allow systematic analyses of miRNA regulation.
Project description:Maturation of canonical microRNA (miRNA) is initiated by DROSHA that cleaves the primary transcript (pri-miRNA). Over 1,800 miRNA loci are annotated in humans, but it remains largely unknown if and at which sites the pri-miRNAs are cleaved by DROSHA. Here we performed in vitro processing on a full set of human pri-miRNAs (miRBase v21) followed by sequencing. This comprehensive profiling enabled us to classify miRNAs based on DROSHA-dependence and map their cleavage sites with respective processing efficiency measures. Only 758 pri-miRNAs are confidently processed by DROSHA, while the majority may be non-canonical or false entries. Analyses of the DROSHA-dependent pri-miRNAs show key cis-elements for processing. We observe widespread alternative processing as well as unproductive cleavage events such as “nick” or “inverse” processing. SRSF3 is a broad-acting auxiliary factor modulating alternative processing and suppressing unproductive processing. The profiling data and methods developed in this study will allow systematic analyses of miRNA regulation.
Project description:Maturation of canonical microRNA (miRNA) is initiated by DROSHA that cleaves the primary transcript (pri-miRNA). Over 1,800 miRNA loci are annotated in humans, but it remains largely unknown if and at which sites the pri-miRNAs are cleaved by DROSHA. Here we performed in vitro processing on a full set of human pri-miRNAs (miRBase v21) followed by sequencing. This comprehensive profiling enabled us to classify miRNAs based on DROSHA-dependence and map their cleavage sites with respective processing efficiency measures. Only 758 pri-miRNAs are confidently processed by DROSHA, while the majority may be non-canonical or false entries. Analyses of the DROSHA-dependent pri-miRNAs show key cis-elements for processing. We observe widespread alternative processing as well as unproductive cleavage events such as “nick” or “inverse” processing. SRSF3 is a broad-acting auxiliary factor modulating alternative processing and suppressing unproductive processing. The profiling data and methods developed in this study will allow systematic analyses of miRNA regulation.
Project description:We used a modified PAS-Seq protocol to map sites of polyadenylation genome-wide in primary breast tissue. Here, we present a map of breast poly(A)-sites derived from six ER+ tumors, six ER- tumors, and adjacent normal tissue from each of the 12 tumor donors.
Project description:All classes of RNA undergo processing. The two largest RNA processing complexes are those involved in rRNA biogenesis and mRNA splicing. Because of their complexity and essential roles, it has been difficult to dissect the functional interactions within these machines as well as to identify possible cross-talk with other steps in gene expression. Here we report the results of a high-density, quantitative genetic interaction map comprising 107,155 individual interactions involving 552 mutants, 166 of which are hypomorphic alleles of essential genes (This data is available at The Krogan Lab Interactome Database). Our data allow unique insights into the functional organization of the RNA processing machines. For example, we identify unexpected connections involving a component of the 19S proteasome, Sem1/Dss1. We show that Sem1 has genetic, physical and functional interactions with the mRNA export complex, Thp1-Sac3; it also interacts physically with a putative component of the COP9 signalosome, Csn12. We show using splicing-specific microarrays that Csn12 has an unanticipated role in mRNA splicing. Finally, we demonstrate the utility of this dataset in determining functions for uncharacterized ORFs. We show that deletion of the uncharacterized YNR004W causes a very similar splicing defect to that caused by deletion of TGS1, the enzyme that trimethylates the caps of snRNAs and snoRNAs. Keywords: E-MAP, RNA Processing, splicing, splicing-specific microarray, CSN12, COP9 signalosome
Project description:All classes of RNA undergo processing. The two largest RNA processing complexes are those involved in rRNA biogenesis and mRNA splicing. Because of their complexity and essential roles, it has been difficult to dissect the functional interactions within these machines as well as to identify possible cross-talk with other steps in gene expression. Here we report the results of a high-density, quantitative genetic interaction map comprising 107,155 individual interactions involving 552 mutants, 166 of which are hypomorphic alleles of essential genes (This data is available at The Krogan Lab Interactome Database). Our data allow unique insights into the functional organization of the RNA processing machines. For example, we identify unexpected connections involving a component of the 19S proteasome, Sem1/Dss1. We show that Sem1 has genetic, physical and functional interactions with the mRNA export complex, Thp1-Sac3; it also interacts physically with a putative component of the COP9 signalosome, Csn12. We show using splicing-specific microarrays that Csn12 has an unanticipated role in mRNA splicing. Finally, we demonstrate the utility of this dataset in determining functions for uncharacterized ORFs. We show that deletion of the uncharacterized YNR004W causes a very similar splicing defect to that caused by deletion of TGS1, the enzyme that trimethylates the caps of snRNAs and snoRNAs. Keywords: E-MAP, RNA Processing, splicing, splicing-specific microarray, CSN12, COP9 signalosome Splicing-specific microarrays were used to assay the changes to splicing caused by deletion of several non-essential genes which had no previously characterized role in mRNA splicing but were suggested to be involved in this process by high-throughput genetic and/or protein-protein interaction data in Saccharomyces cerevisiae. The data includes samples collected from some mutants in log phase growth at 30 degrees C and from some mutants shifted to 16 degrees C, all competitively hybridized against wild type samples collected under the same conditions. .
Project description:Most eukaryotic mRNAs are enzymatically processed before they are translated, but less is known about mRNA processing in prokaryotes. While bacterial rRNAs and tRNAs are known to be highly processed, only a handful of bacterial mRNAs have been shown to be processed by ribonucleases, typically altering transcript stability. We hypothesized that mRNA processing might be more widespread in prokaryotes and constitute a previously underappreciated layer of post-transcriptional regulation. We therefore adapted RNA-seq methodologies to map transcript 5’ ends across the Mycobacterium tuberculosis transcriptome, distinguishing between transcriptional start sites (TSSs) and RNA processing sites. We report for the first time genome-wide mRNA endonucleolytic cleavage patterns in a prokaryote, and find that mRNA processing is widespread in M. tuberculosis. This has physiologic consequences, as mRNA cleavage plays a regulatory function in the ESX-1 locus by producing a transcript fragment encoding the secreted proteins EsxB and EsxA that is significantly more stable than the parent transcript, leading to greater steady-state transcript abundance. At least 20 other loci display similar patterns of processing-associated differences in transcript levels in M. tuberculosis. Mycobacteria therefore use mRNA processing to effect differential abundance of sub-sections of polycistronic transcripts, which may provide additional layers of regulation. Moreover, our results demonstrate that stable, processed mRNAs are a ubiquitous feature in this prokaryotic transcriptome, suggesting that mRNA processing may represent a major post-transcriptional regulatory mechanism. RNA from two biological replicate cultures was analyzed by RNA-seq for expression analysis and 5'-end-mapping for identification of transcriptional start sites and RNA processing sites. An additional set of three biological replicate cultures were analyzed by RNA-seq for expression analysis using a different library construction method.