A dual-activity topoisomerase complex regulates mRNA translation and turnover
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ABSTRACT:
PROVIDER: PRJNA779461 | ENA |
REPOSITORIES: ENA
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Project description:Topoisomerase 3β (TOP3B) and TDRD3 form a dual-activity topoisomerase complex that interacts with FMRP and can change the topology of both DNA and RNA. Here, we investigated the post-transcriptional influence of TOP3B and associated proteins on mRNA translation and turnover. First, we discovered that in human HCT116 colon cancer cells, knock-out (KO) of TOP3B had similar effects on mRNA turnover and translation as did TDRD3-KO, while FMRP-KO resulted in rather distinct effects, indicating that TOP3B had stronger coordination with TDRD3 than FMRP in mRNA regulation. Second, we identified TOP3B-bound mRNAs in HCT116 cells; we found that while TOP3B did not directly influence the stability or translation of most TOP3B target mRNAs, it stabilized a subset of target mRNAs but had a more complex effect on translation--enhancing for some mRNAs whereas reducing for others. Interestingly, a point mutation that specifically disrupted TOP3B catalytic activity only partially recapitulated the effects of TOP3B-KO on mRNA stability and translation, suggesting that the impact of TOP3B on target mRNAs is only in part linked to its ability to change topology of mRNAs. Collectively, our data suggest that TOP3B-TDRD3 can regulate mRNA translation and turnover by mechanisms that are dependent and independent of topoisomerase activity.
2022-06-08 | GSE188574 | GEO
Project description:Topoisomerase 3β (TOP3B) and TDRD3 form a dual-activity topoisomerase complex that interacts with FMRP and can change the topology of both DNA and RNA. Here, we investigated the post-transcriptional influence of TOP3B and associated proteins on mRNA translation and turnover. First, we discovered that in human HCT116 colon cancer cells, knock-out (KO) of TOP3B had similar effects on mRNA turnover and translation as did TDRD3-KO, while FMRP-KO resulted in rather distinct effects, indicating that TOP3B had stronger coordination with TDRD3 than FMRP in mRNA regulation. Second, we identified TOP3B-bound mRNAs in HCT116 cells; we found that while TOP3B did not directly influence the stability or translation of most TOP3B target mRNAs, it stabilized a subset of target mRNAs but had a more complex effect on translation-enhancing for some mRNAs whereas reducing for others. Interestingly, a point mutation that specifically disrupted TOP3B catalytic activity only partially recapitulated the effects of TOP3B-KO on mRNA stability and translation, suggesting that the impact of TOP3B on target mRNAs is partly linked to its ability to change topology of mRNAs. Collectively, our data suggest that TOP3B-TDRD3 can regulate mRNA translation and turnover by mechanisms that are dependent and independent of topoisomerase activity.
| S-EPMC9262614 | biostudies-literature
Project description:Eukaryotic topoisomerase I and II relax DNA and are key components in the processes of DNA replication, transcription and genome stability. It is not clear, however, how their activity controls epigenetic states across an entire eukaryotic genome. Using the fission yeast model Schizosaccharomyces pombe, we investigate genome-wide how topoisomerases affect chromatin formation through nucleosome occupancy and regulate transcription. We show that topoisomerase activity is required for nucleosome turnover at promoter regions, affecting epigenetic gene regulatory states, and for effective termination of transcription.
2010-07-02 | E-MEXP-1850 | biostudies-arrayexpress
Project description:Topoisomerases are required to release topological stress generated by RNA polymerase II (RNAPII) during transcription. Here we show that in response to starvation, the complex of topoisomerase 3b (TOP3B) and TDRD3 can promote transcriptional activation or repression. Human HCT116 cells individually inactivated for TOP3B, TDRD3, or TOP3B topoisomerase activity, exhibit similarly disrupted transcription for both starvation-activated genes (SAGs) and starvation-repressed genes (SRGs). Responding to starvation, both TOP3B-TDRD3 and the elongating form of RNAPII exhibit concomitantly increased binding to TOP3B-dependent SAGs, at binding sites that overlap. Strikingly, TOP3B inactivation decreases the binding of elongating RNAPII to TOP3B-dependent SAGs while increased it to SRGs. Furthermore, TOP3B-ablated cells display reduced transcription of several autophagy-associated genes and autophagy per se. Our data suggest that TOP3B-TDRD3 can promote both transcriptional activation and repression by regulating RNAPII distribution. In addition, the findings that it can facilitate autophagy may account for the shortened lifespan of Top3b-KO mice.
2023-02-01 | GSE214322 | GEO
Project description:A dual-activity topoisomerase complex promotes both transcriptional activation and repression in response to starvation
| PRJNA884750 | ENA
Project description:Topoisomerase 3b (Top3b) is the only dual-activity topoisomerase in animals that can change topology for both DNA and RNA, and facilitate transcription on DNA and translation on mRNAs. Top3b mutation has been linked to schizophrenia, autism, epilepsy, and cognitive impairment. However, whether and how Top3b mutations are causal to these disorders remain unclear. Here we show that Top3b knockout mice exhibit behavioral phenotypes related to psychiatric disorders and cognitive impairment, including increased anxiety and fear, abnormal social interactions, impaired context discrimination, and defective spatial learning and memory. In addition, these mice display deficits in adult hippocampal neurogenesis and synaptic plasticity. Notably, the brains of the mutant mice exhibit impaired global neuronal activity-dependent transcription in response to fear conditioning stress, and the affected genes include many that are critical for neuronal functions and mental health. Our data suggest that Top3b is essential for normal brain function in multiple domains, and defective neuronal activity-dependent transcription may be a mechanism by which Top3b deletion causes cognitive impairment and psychiatric disorders.
2020-05-22 | GSE145730 | GEO
Project description:In response to foreign and endogenous double-stranded RNA (dsRNA), protein kinase R (PKR) and ribonuclease L (RNase L) reprogram translation in mammalian cells. PKR inhibits translation initiation through eIF2 phosphorylation, which triggers stress granule (SG) formation and promotes translation of stress responsive mRNAs. The mechanisms of RNase L-driven translation repression, its contribution to SG assembly, and its regulation of dsRNA stress-induced mRNAs are unknown. We demonstrate that RNase L drives translational shut-off in response to dsRNA by promoting widespread turnover of mRNAs. This alters stress granule assembly and reprograms translation by only allowing for the translation of mRNAs resistant to RNase L degradation, including numerous antiviral mRNAs such as IFN- . Individual cells differentially activate dsRNA responses revealing variation that can affect cellular outcomes. This identifies bulk mRNA degradation and the resistance of antiviral mRNAs as the mechanism by which RNaseL reprograms translation in response to dsRNA.
2019-07-10 | GSE124144 | GEO
Project description:Bacterial Stress Bodies – Ancestral Condensates Regulating RNA Turnover and Protein Translation
| PRJNA1007683 | ENA
Project description:The cancer target enyzme topoisomerase 1 transiently cleaves one strand of chromosomal DNA to relax accumulated strain that can prevent transcription, replication or chromatin assembly. The topoisomerase 1 poison camptothecin and its synthetic analogs are widely used chemotherapeutics that act by trapping the enzyme on DNA in a ‘covalent complex’, resulting in persistent DNA damage and cell death. The prevailing model, interfacial inhibition, contends that the covalent complex is trapped by drug binding alone. In contrast, here we show that camptothecins produce extensive oxidative stress and that topoisomerase 1 is reactive with electrophilic second messengers of oxidative damage. We show that blocking oxidative stress in cells inhibits covalent complex formation by camptothecin, while electrophiles such as 4-hydroxynonenal are able to induce covalent complex formation in cells on their own. Towards mechanism of action, we show that 4-hydroxynonenal electrophilically modifies a cysteine within the DNA-binding active site of human topoisomerase 1. Taken together, our results suggest a mechanism in which oxidative stress mediates the effects of many topoisomerase 1 poisons, and suggest that this critical DNA-regulating enzyme may have a dual role as a sensor of cellular redox stress, linking oxidative stress to DNA damage response in cancer cells.
2021-03-24 | PXD018549 | Pride
Project description:Rnase L reprograms translation by widespread mRNA turnover escaped by antiviral mRNAs
| PRJNA510831 | ENA