Browse
Submit Data
Databases
API
Help

Dataset Information

0 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Human telomerase RNA processing and quality control

ABSTRACT: Primary telomerase RNA transcripts are processed into shorter mature forms that assemble into a complex with the catalytic subunit and provide the template for telomerase activity. In diverse fungi telomerase RNA 3’ end processing involves a single cleavage reaction by the spliceosome akin to the first step of splicing. Longer forms of human telomerase RNA (hTR) have been reported, but how the mature form of precisely 451 nucleotides is generated is still unknown. We now show that the splicing inhibitor isoginkgetin causes accumulation of long hTR transcripts, but find no evidence for a direct role for splicing in hTR processing. Instead, isoginkgetin mimics the effects of inhibiting the RNA exosome. Depletion of exosome components and accessory factors reveals functions for the cap binding complex (CBC) and the nuclear exosome targeting (NEXT) complex in hTR turnover. Whereas longer transcripts are predominantly degraded, shorter precursor RNAs are oligo-adenylated by TRF4-2 and either processed by poly (A) specific ribonuclease (PARN) or degraded by the exosome. Our results reveal that hTR biogenesis involves a kinetic competition between RNA processing and quality control pathways and suggest new treatment options for dyskeratosis congenita caused by mutations in RNA processing factors.

ORGANISM(S): Homo sapiens

PROVIDER: GSE73776 | GEO | 2015/11/25

SECONDARY ACCESSION(S): PRJNA297872

REPOSITORIES: GEO

ACCESS DATA

Json Xml

Dataset's files

Source:

			Action	DRS
		Other

Items per page:

1 - 1 of 1

Similar Datasets

Human telomerase RNA processing and quality control

Project description:Primary telomerase RNA transcripts are processed into shorter mature forms that assemble into a complex with the catalytic subunit and provide the template for telomerase activity. In diverse fungi telomerase RNA 3â end processing involves a single cleavage reaction by the spliceosome akin to the first step of splicing. Longer forms of human telomerase RNA (hTR) have been reported, but how the mature form of precisely 451 nucleotides is generated is still unknown. We now show that the splicing inhibitor isoginkgetin causes accumulation of long hTR transcripts, but find no evidence for a direct role for splicing in hTR processing. Instead, isoginkgetin mimics the effects of inhibiting the RNA exosome. Depletion of exosome components and accessory factors reveals functions for the cap binding complex (CBC) and the nuclear exosome targeting (NEXT) complex in hTR turnover. Whereas longer transcripts are predominantly degraded, shorter precursor RNAs are oligo-adenylated by TRF4-2 and either processed by poly (A) specific ribonuclease (PARN) or degraded by the exosome. Our results reveal that hTR biogenesis involves a kinetic competition between RNA processing and quality control pathways and suggest new treatment options for dyskeratosis congenita caused by mutations in RNA processing factors. We cloned and sequenced 3â ends by RLM-RACE coupled with high-throughput sequencing to gain further insights into hTR processing.

2015-11-25 | E-GEOD-73776 | biostudies-arrayexpress

The H/ACA complex disrupts triplex in hTR precursor to permit processing by RRP6 and PARN

Project description:Human telomerase RNA (hTR) is transcribed as a precursor that is then posttranscriptionally modified and processed. A fraction of the transcripts is oligoadenylated by TRAMP and either processed into the mature hTR or degraded by the exosome. Here, we characterize the processing of 3’ extended forms of varying length by PARN and RRP6. We show that tertiary RNA interactions unique to the longer precursor forms favor RNA degradation, whereas H/ACA RNP assembly stimulates productive processing. Interestingly, the H/ACA complex actively promotes processing in addition to protecting the mature 3’ end. Processing occurs in two steps with longer forms being trimmed by RRP6 and shorter forms being preferentially processed by PARN. These results reveal how RNA structure and RNP assembly affect the kinetics of processing and degradation and ultimately determine the amount of functional telomerase produced in cells.

2018-12-26 | GSE111081 | GEO

Human telomerase RNA processing and quality control

Project description:RNA sequencing of HeLa cells treated with siRNA against the RNA exosome components hRRP40, hRRP6, hDIS3, and hRRP6/hDIS3 or the splicing inhibitors Isoginkgetin and spliceostatin A, respectively. Stranded, ribo-depleted RNA seq profiles of HeLa cells treated with exosome targeting siRNAs or splicing inhibitors using Illumina HiSeq. All experiments were carried out in triplicate starting with independent cell cultures

2015-11-25 | E-GEOD-72055 | biostudies-arrayexpress

Maturation of human telomerase RNA component from an extended precursor

Project description:Here, we develop nascent RNAend-Seq, in which we isolate nascent RNA and sequence the 3' ends of RNA precursors. Using a pulse-chase experimental design, we follow extended precursors of the telomerase RNA component (hTR) and show that the mature telomerase RNA derives from these species with slow kinetics compared to other small non-coding RNAs. The human disease causing gene PARN further delays maturation of the hTR precursor in PARN- mutant cancer cell lines. Disruption of the poly(A)polymerase PAPD5 in PARN-mutant cells restores normal processing kinetics and levels of mature hTR. Unexpectedly, neither PARN nor PAPD5 is required for hTR processing. Instead, PAPD5 and PARN set the hTR maturation rate by controlling precursor adenylation.

2019-03-28 | GSE117054 | GEO

Dissecting telomerase RNA structural heterogeneity in living human cells with DMS-MaPseq

Project description:Telomerase is a specialized reverse transcriptase that uses an intrinsic RNA subunit as the template for telomeric DNA synthesis. Biogenesis of human telomerase requires its RNA subunit (hTR) to fold into a multi-domain architecture that includes the template-containing pseudoknot (t/PK) and the three-way junction (CR4/5). These two hTR domains bind the telomerase reverse transcriptase (hTERT) protein and are thus essential for telomerase catalytic activity. Here, we probe the structure of hTR in living cells using dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) and ensemble deconvolution analysis. Unexpectedly, approximately 15% of the steady state population of hTR has a CR4/5 conformation lacking features required for hTERT binding. Mutagenesis demonstrates that stabilization of the alternative CR4/5 conformation is detrimental to telomerase assembly and activity. We propose that this misfolded portion of the cellular hTR pool is either slowly refolded or degraded. Thus, kinetic traps for RNA folding that have been so well-studied in vitro may also present barriers for assembly of ribonucleoprotein complexes in vivo.

2023-10-20 | GSE245536 | GEO

Human telomerase RNA processing and quality control

2015-11-25 | GSE72055 | GEO

LARP3, LARP7, and MePCE are Involved in the Early Stage of Human Telomerase RNA Biogenesis

Project description:Human telomerase assembly is a highly dynamic process. Using biochemical approaches, we found that LARP3 and LARP7/MePCE are involved in the early stage and that their binding to hTR is destabilized when the mature hTR is produced. LARP3 plays a negative role in preventing the processing of the 3′-extended long (exL) form and binding of LARP7 and MePCE. Interestingly, the tertiary structure of the exL form prevents LARP3 binding and facilitates hTR biogenesis. Supporting this process, LARP3 at low levels promotes hTR maturation, increases telomerase activity, and elongates telomeres. LARP7 and MePCE knockdown inhibits the conversion of the 3′-extended short (exS) form into mature hTR and the cytoplasmic accumulation of hTR, resulting in telomere shortening. Our data suggest that LARP3 and LARP7/MePCE mediate the processing of hTR precursors and thus control the production of functional telomerase.

2024-07-25 | GSE262590 | GEO

Next generation sequencing identifies polyadenylated species of hTR

Project description:The paired-end next-generation sequencing of all hTR versions of less than 200 nucleotides in length was used to analyze the 3’ end distribution of hTR associated to Flag-tagged versions of PABPN1, hTERT and Dyskerin. In total, we obtained 2,716,342, 3,152,013, and 3,077,395 hTR-specific reads for the PABPN1, hTERT, and Dyskerin purifications, respectively. We found that the majority of polyadenylated telomerase RNA recovered in the PABPN1, hTERT, and Dyskerin purifications had poly(A) tails starting immediately after the annotated hTR 3’ end. However, a greater proportion of poly(A) tails were found on genome-encoded 3’-extentions in the PABPN1-bound fraction compared to the population of hTR that was copurified with hTERT and DKC1: 15.5% for PABPN1, 6.9% for hTERT, and 6.5% for Dyskerin. Notably, the population of polyadenylated telomerase RNA recovered with PABPN1 was significantly different in terms of poly(A) tail length compared to polyadenylated hTR retrieved in the hTERT- and Dyskerin-bound fractions (P-value=5.551e-16, Kolmogorov-Smirnov test), showing a tendency toward longer poly(A) tails in the PABPN1-bound fraction. The enrichment of telomerase RNA with long poly(A) tails in the PABPN1-bound fraction is consistent with a role of PABPN1 in a maturation pathway that depends on hTR 3’ end polyadenylation. Moreover, our results indicate that a fraction of hTERT and Dyskerin are associated with polyadenylated versions of hTR.

2015-10-21 | GSE74186 | GEO

DGCR8 acts as a novel adaptor for the exosome complex to degrade double-stranded structured RNAs

Project description:The Microprocessor complex (DGCR8/Drosha) is required for microRNA (miRNA) biogenesis but also binds and regulates the stability of several types of cellular RNAs. Of particular interest, DGCR8 controls the stability of mature small nucleolar RNA (snoRNA) transcripts independently of Drosha, suggesting the existence of alternative DGCR8 complex/es with other nucleases to process a variety of cellular RNAs. Here, we found that DGCR8 co-purifies with subunits of the nuclear exosome, preferentially associating with its hRRP6-containing nucleolar form. Importantly, we demonstrate that DGCR8 is essential for the recruitment of the exosome to snoRNAs and to human telomerase RNA. In addition, we show that the DGCR8/exosome complex controls the stability of the human telomerase RNA component (hTR/TERC). Altogether, these data suggests that DGCR8 acts as a novel adaptor to recruit the exosome complex to structured RNAs and induce their degradation.

2015-12-10 | GSE73376 | GEO

DGCR8 acts as a novel adaptor for the exosome complex to degrade double-stranded structured RNAs

2015-12-10 | E-GEOD-73376 | biostudies-arrayexpress