Denaturing purifications demonstrate that PRC2 and other widely-reported chromatin proteins do not appear to bind directly to RNA in vivo
Ontology highlight
ABSTRACT:
ORGANISM(S): Mus musculus Mus Homo sapiens
PROVIDER: GSE253477 | GEO | 2024/02/20
REPOSITORIES: GEO
Similar Datasets
Project description:The Polycomb Repressive Complex 2 (PRC2) has been reported to bind to many RNAs and has become a central player in reports describing the mechanisms of how long non-coding RNAs (lncRNAs) regulate gene expression. Based largely on these observations of PRC2, many additional chromatin proteins have similarly been reported to bind RNA to enact their functions. Yet, there is a growing discrepancy between the biochemical evidence supporting specific lncRNA-PRC2 interactions and functional evidence demonstrating that PRC2 is often dispensable for lncRNA function. Here we revisit the evidence supporting broad RNA binding by PRC2 and other chromatin proteins and show that many previously reported RNA-protein interactions do not represent in vivo interactions. We find that denaturing purification of in vivo crosslinked RNA-protein complexes leads to loss of detectable PRC2-RNA interactions. Similarly, we fail to detect in vivo RNA binding of other chromatin-associated proteins previously reported to bind RNA (CTCF, YY1, WDR5, and others), despite accurately mapping bona fide RNA-protein binding sites across a range of proteins including several specific chromatin-associated proteins (SPEN, CHTOP, TET2, and others). Taken together, these results argue for a critical re-evaluation of the broad role of RNA binding to orchestrate various chromatin regulatory mechanisms.
2024-02-20 | GSE253475 | GEO
Project description:The Polycomb Repressive Complex 2 (PRC2) has been reported to bind to many RNAs and has become a central player in reports describing the mechanisms of how long non-coding RNAs (lncRNAs) regulate gene expression. Based largely on these observations of PRC2, many additional chromatin proteins have similarly been reported to bind RNA to enact their functions. Yet, there is a growing discrepancy between the biochemical evidence supporting specific lncRNA-PRC2 interactions and functional evidence demonstrating that PRC2 is often dispensable for lncRNA function. Here we revisit the evidence supporting broad RNA binding by PRC2 and other chromatin proteins and show that many previously reported RNA-protein interactions do not represent in vivo interactions. We find that denaturing purification of in vivo crosslinked RNA-protein complexes leads to loss of detectable PRC2-RNA interactions. Similarly, we fail to detect in vivo RNA binding of other chromatin-associated proteins previously reported to bind RNA (CTCF, YY1, WDR5, and others), despite accurately mapping bona fide RNA-protein binding sites across a range of proteins including several specific chromatin-associated proteins (SPEN, CHTOP, TET2, and others). Taken together, these results argue for a critical re-evaluation of the broad role of RNA binding to orchestrate various chromatin regulatory mechanisms.
2024-02-20 | GSE253466 | GEO
Project description:Denaturing purifications demonstrate that PRC2 and other widely-reported chromatin proteins do not appear to bind directly to RNA in vivo
| PRJNA1065860 | ENA
Project description:Denaturing purifications demonstrate that PRC2 and other widely-reported chromatin proteins do not appear to bind directly to RNA in vivo [ChIP-seq]
| PRJNA1065869 | ENA
Project description:Denaturing purifications demonstrate that PRC2 and other widely-reported chromatin proteins do not appear to bind directly to RNA in vivo [CLIP and CLAP]
| PRJNA1065851 | ENA
Project description:Cryptococcosis is an infectious disease of global significance for which new therapies are needed. Repurposing previously developed drugs for new indications can expedite the translation of new therapies from bench to beside. Here, we characterized the anti-cryptococcal activity and antifungal mechanism of estrogen receptor antagonists related to the breast cancer drugs tamoxifen and toremifene. Tamoxifen and toremifene are fungicidal and synergize with fluconazole and amphotericin B in vitro. In a mouse model of disseminated cryptococcosis, tamoxifen at concentrations achievable in humans combines with fluconazole to decrease brain burden by ~1 log10. In addition, these drugs inhibit the growth of Cryptococcus neoformans within macrophages, a niche not accessible by current antifungal drugs. Toremifene and tamoxifen directly bind to the essential EF hand protein calmodulin, as determined by thermal shift assays with purified C. neoformans calmodulin (Cam1), prevent Cam1 from binding to its well-characterized substrate calcineurin (Cna1), and block Cna1 activation. In whole cells, toremifene and tamoxifen block the calcineurin-dependent nuclear localization of the transcription factor Crz1. A large-scale chemical genetic screen with a library of C. neoformans deletion mutants identified a second EF hand-containing protein, which we have named calmodulin-like protein 1 (CNAG_05655), as a potential target, and further analysis showed that toremifene directly binds Cml1 and modulates its ability to bind and activate Cna1. Importantly, tamoxifen analogs (idoxifene and methylene-idoxifene) with increased calmodulin antagonism display improved anti-cryptococcal activity, indicating that calmodulin inhibition can be used to guide a systematic optimization of the anti-cryptococcal activity of the triphenylethylene scaffold.Worldwide, cryptococcosis affects approximately 1 million people annually and kills more HIV/AIDS patients per year than tuberculosis. The gold standard therapy for cryptococcosis is amphotericin B plus 5-flucytosine, but this regimen is not readily available in regions where resources are limited and where the burden of disease is highest. Herein, we show that molecules related to the breast cancer drug tamoxifen are fungicidal for Cryptococcus and display a number of pharmacological properties desirable for an anti-cryptococcal drug, including synergistic fungicidal activity with fluconazole in vitro and in vivo, oral bioavailability, and activity within macrophages. We have also demonstrated that this class of molecules targets calmodulin as part of their mechanism of action and that tamoxifen analogs with increased calmodulin antagonism have improved anti-cryptococcal activity. Taken together, these results indicate that tamoxifen is a pharmacologically attractive scaffold for the development of new anti-cryptococcal drugs and provide a mechanistic basis for its further optimization.
| S-EPMC3950514 | biostudies-other
Project description:Polycomb repressive complex 2 (PRC2) is a key epigenetic multiprotein complex involved in the regulation of gene expression in metazoans. PRC2 is formed by a tetrameric core that endows the complex with histone methyltransferase activity, allowing it to mono-, di- and tri-methylate histone H3 on lysine 27 (H3K27me1/2/3); H3K27me3 is a hallmark of facultative heterochromatin. The core complex of PRC2 is bound by several associated factors that are responsible for modulating its targeting specificity and enzymatic activity. Depletion and/or mutation of the subunits of this complex can result in severe developmental defects, or even lethality. Furthermore, mutations of these proteins in somatic cells can be drivers of tumorigenesis, by altering the transcriptional regulation of key tumour suppressors or oncogenes. In this review, we present the latest results from structural studies that have characterised PRC2 composition and function. We compare this information with data and literature for both gain-of function and loss-of-function missense mutations in cancers to provide an overview of the impact of these mutations on PRC2 activity.
| S-EPMC7000746 | biostudies-literature
Project description:Pumilio paralogs, PUM1 and PUM2, are sequence-specific RNA-binding proteins that are essential for vertebrate development and neurological functions. PUM1&2 negatively regulate gene expression by accelerating degradation of specific mRNAs. Here, we determined the repression mechanism and impact of human PUM1&2 on the transcriptome. We identified subunits of the CCR4-NOT (CNOT) deadenylase complex required for stable interaction with PUM1&2 and to elicit CNOT-dependent repression. Isoform-level RNA sequencing revealed broad coregulation of target mRNAs through the PUM-CNOT repression mechanism. Functional dissection of the domains of PUM1&2 identified a conserved amino-terminal region that confers the predominant repressive activity via direct interaction with CNOT. In addition, we show that the mRNA decapping enzyme, DCP2, has an important role in repression by PUM1&2 amino-terminal regions. Our results support a molecular model of repression by human PUM1&2 via direct recruitment of CNOT deadenylation machinery in a decapping-dependent mRNA decay pathway.
| S-EPMC7962487 | biostudies-literature
Project description:Specialized adult somatic cells, such as cardiomyocytes (CMs), are highly differentiated with poor renewal capacity, an integral reason underlying organ failure in disease and aging. Among the least renewable cells in the human body, CMs renew approximately 1% annually. Consistent with poor CM turnover, heart failure is the leading cause of death. Here, we show that an active version of the Hippo pathway effector YAP, termed YAP5SA, partially reprograms adult mouse CMs to a more fetal and proliferative state. One week after induction, 19% of CMs that enter S-phase do so twice, CM number increases by 40%, and YAP5SA lineage CMs couple to pre-existing CMs. Genomic studies showed that YAP5SA increases chromatin accessibility and expression of fetal genes, partially reprogramming long-lived somatic cells in vivo to a primitive, fetal-like, and proliferative state.
| S-EPMC6435425 | biostudies-literature
Project description:Pumilio paralogs, PUM1 and PUM2, are sequence-specific RNA-binding proteins that are essential for vertebrate development and neurological functions. PUM1&2 function to negatively regulate gene expression by accelerating degradation of specific mRNAs. Here, we determined the repression mechanism and impact of human PUM1&2 on the transcriptome. We identified subunits of the CCR4-NOT (CNOT) deadenylase complex required for stable interaction with PUM1&2 and to elicit CNOT-dependent repression. Isoform-level RNA sequencing revealed broad co-regulation of target mRNAs through the PUM-CNOT repression mechanism. Functional dissection of the domains of PUM1&2 identified a conserved N-terminal region that confers the predominant repressive activity via direct interaction with CNOT. In addition, we show that the DCP2 mRNA decapping enzyme has an important role in repression by PUM1&2 N-terminal regions. Our results support a molecular model of repression by human PUM1&2 via direct recruitment of CNOT deadenylation machinery in a decapping-dependent pathway.
2021-09-09 | GSE159510 | GEO