Similar Datasets
Project description:We analysed the effect of depriving the human cell of the catalytic activity of the nuclear 5’ to 3’ exoribonuclease XRN2. Catalytic amino acids in this protein had been defined previously, so it was possible to design a mutated catalytically inactive form of the protein (XRN2D233A-D235A) (PMID: 19194460). We created 293 Flp-In T-REx stable cell lines that induciby silence endogenous XRN2, and concomitantly express wild-type or inactive XRN2 in fusion with EGFP at the C-terminus. Thus, complementation of silencing of endogenous XRN2 with the expression of mutant version of the protein allows to directly link potential phenotypes with the lack of XRN2 enzymatic activity. To this end we isolated total RNA from tetracycline-treated cells, depleted it from rRNA and conducted strand-specific deep sequencing.
2018-04-17 | GSE99421 | GEO
Project description:The exonuclease torpedo Xrn2 loads onto nascent RNA 5’-PO4 ends and chases down pol II to promote termination downstream of polyA sites. We report that Xrn2 is recruited to pre-initiation complexes and “travels” to 3’ ends of genes. Mapping of 5’-PO4 ends in nascent RNA identified Xrn2 loading sites stabilized by an active site mutant, Xrn2(D235A). Xrn2 loading sites are ~2-20 bases downstream of where CPSF73 cleaves at polyA sites and histone 3’ ends. We propose that processing of all mRNA 3’ ends comprises cleavage and limited 5’-3’ trimming by CPSF73 followed by hand-off to Xrn2. A similar hand-off occurs at tRNA 3’ ends where co-transcriptional RNAseZ cleavage generates novel Xrn2 substrates. Exonuclease-dead Xrn2 increased transcription in 3’ flanking regions by inhibiting polyA site-dependent termination. Surprisingly, the mutant Xrn2 also rescued transcription in promoter-proximal regions to the same extent as in 3’ flanking regions. eNET-seq revealed Xrn2-mediated degradation of sense and anti-sense nascent RNA within a few bases of the TSS where 5’-PO4 ends may be generated by decapping or endonucleolytic cleavage. These results suggest that a major fraction of pol II complexes terminate prematurely close to the start site under normal conditions by an Xrn2-mediated torpedo mechanism.
2022-11-17 | GSE217033 | GEO
Project description:To identify changes in gene expression following EXOSC10 and XRN2 silencing, 3'-end RNA-sequencing was performed on RNA extracted from shEXOSC10 and shXRN2 cells.
2019-12-26 | GSE130865 | GEO
Project description:Transcription termination was analyzed by anti RNA pol II ChIP-seq in isogenic human HEK293 cell lines that inducibly express a-amanitin resistant mutants of the RNA polymerase II large subunit with slow and fast elongation rates and in lines that inducbily over-express WT or an active site mutant of the RNA exonuclease "torpedo" Xrn2. Transcription termination zones were mapped by anti-pol II ChIP-seq under conditions where transcription elongation rate was increased or decreased by point mutations in the large subunit of the enzyme. Termination was also assayed under conditions where Xrn2 exonuclease activity was inhibited by over-expression of an active site mutant (D235A).
2015-11-19 | E-GEOD-72800 | biostudies-arrayexpress
Project description:Termination is a ubiquitous phase in every transcription cycle but is incompletely understood and a subject of debate. We have used gene editing as a new approach to address its mechanism through engineered conditional depletion of the 5’-3’ exonuclease, Xrn2, or the polyadenylation signal (PAS) endonuclease, CPSF73. The ability to rapidly control Xrn2 reveals a clear and general role for it in co-transcriptional degradation of 3’ flanking region RNA and transcriptional termination. This defect is characterised genome-wide, at high resolution, using native elongating transcript sequencing (mNET-seq). An Xrn2 effect on termination requires prior RNA cleavage and we provide evidence for this by showing that catalytically inactive CPSF73 cannot restore termination to cells lacking functional CPSF73. Notably, Xrn2 plays no significant role in either Histone or snRNA gene termination even though both RNA classes undergo 3’ end cleavage. In sum, efficient termination on most protein-coding genes involves CPSF73 mediated RNA cleavage and co-transcriptional degradation of polymerase-associated RNA by Xrn2. However, as CPSF73 loss caused more extensive read-through transcription than Xrn2 elimination, it likely plays a more underpinning role in termination.
2018-02-13 | GSE109003 | GEO
Project description:XRN2 is a conserved 5â??-->3â?? exoribonuclease that complexes with XTB-domain containing proteins. Thus, in Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3'(2'),5'-bisphosphate nucleotidase 1 (BPNT1) through its hydrolysis of 3â??-phosphoadenosine-5'-bisphosphate (PAP), an endogenous XRN inhibitor. Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. Autoregulation appears to be triggered at different thresholds of XRN2 inactivation, such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but similar mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons. Wild-type C. elegans worms were subjected to mock or xrn-2 RNAi from L1 to L4 stage at 20°C. Total RNA was extracted from the worms, and polyadenylated RNA was analyzed.
2016-08-25 | E-GEOD-79994 | biostudies-arrayexpress
Project description:glioblastoma multiforme genomic profiling by single nucleotide polymorphism microarray<br><br>Human GBM (glioblastoma multiforme)cell lines (U87, U118, U138, U343, U373, T98G) were maintained in Dulbecco's modified Eagle's medium with 10 % fetal calf serum, 10 U/ml penicillin-G, and 10 mg/ml streptomycin. All cells were incubated at 37 oC in 5% CO2.<br><br>Four primary GBM explants were established from patients with glioblastoma multiforme undergoing surgery as following described: Tumor specimens were immediately transported to the laboratory, finely minced to single cell suspension and cultured in complete medium [Ham's F-12/DME High Glucose medium containing 10% fetal calf serum, 10 U/ml penicillin-G, and 10 mg/ml streptomycin and 2 mM glutamax-1 into 100 cm2 tissue culture plastic dishes the second passage. All cells were incubated at 37 oC in 5% CO2.<br><br>GBM (glioblastoma multiforme) tissue samples were quick frozen. <br><br>Standard proteinase K-phenol-chloroform extraction method was used to extract DNA from GBM samples, cell lines and explants.<br><br>The matched peripheral blood data can be used as normalized data for their matched tumor tissue data. <br><br>The cell lines samples and two explants without normalized data, but they can be normalized by one of the peripheral blood DNA data.
2009-01-13 | E-MEXP-1330 | biostudies-arrayexpress
Project description:XRN2 is a conserved 5’-->3’ exoribonuclease that complexes with XTB-domain containing proteins. Thus, in Caenorhabditis elegans (C. elegans), the XTBD-protein PAXT-1 stabilizes XRN2 to retain its activity. XRN2 activity is also promoted by 3'(2'),5'-bisphosphate nucleotidase 1 (BPNT1) through its hydrolysis of 3’-phosphoadenosine-5'-bisphosphate (PAP), an endogenous XRN inhibitor. Here, we find through unbiased screening that loss of bpnt-1 function suppresses lethality caused by paxt-1 deletion. This unexpected finding is explained by XRN2 autoregulation, which occurs through repression of a cryptic promoter activity and destabilization of the xrn-2 transcript. Autoregulation appears to be triggered at different thresholds of XRN2 inactivation, such that more robust XRN2 perturbation, by elimination of both PAXT-1 and BPNT1, is less detrimental to worm viability than absence of PAXT-1 alone. Like more than 15% of C. elegans genes, xrn-2 occurs in an operon, and we identify additional operons under its control, consistent with a broader function of XRN2 in polycistronic gene regulation. Regulation occurs through intercistronic regions that link genes in an operon, but similar mechanisms may allow XRN2 to operate on monocistronic genes in organisms lacking operons.
2016-08-25 | GSE79994 | GEO
Project description:We applied the tiling arrays to study the Arabidopsis whole-genome transcriptome in Arabidopsis fry1-6, xrn2-4, xrn3-3 and xrn4-6 mutants.
2012-05-03 | GSE32977 | GEO