1
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D'Orso I. The HIV-1 Transcriptional Program: From Initiation to Elongation Control. J Mol Biol 2024:168690. [PMID: 38936695 DOI: 10.1016/j.jmb.2024.168690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 06/20/2024] [Accepted: 06/21/2024] [Indexed: 06/29/2024]
Abstract
A large body of work in the last four decades has revealed the key pillars of HIV-1 transcription control at the initiation and elongation steps. Here, I provide a recount of this collective knowledge starting with the genomic elements (DNA and nascent TAR RNA stem-loop) and transcription factors (cellular and the viral transactivator Tat), and later transitioning to the assembly and regulation of transcription initiation and elongation complexes, and the role of chromatin structure. Compelling evidence support a core HIV-1 transcriptional program regulated by the sequential and concerted action of cellular transcription factors and Tat to promote initiation and sustain elongation, highlighting the efficiency of a small virus to take over its host to produce the high levels of transcription required for viral replication. I summarize new advances including the use of CRISPR-Cas9, genetic tools for acute factor depletion, and imaging to study transcriptional dynamics, bursting and the progression through the multiple phases of the transcriptional cycle. Finally, I describe current challenges to future major advances and discuss areas that deserve more attention to both bolster our basic knowledge of the core HIV-1 transcriptional program and open up new therapeutic opportunities.
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Affiliation(s)
- Iván D'Orso
- Department of Microbiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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2
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Kowalski MH, Wessels HH, Linder J, Dalgarno C, Mascio I, Choudhary S, Hartman A, Hao Y, Kundaje A, Satija R. Multiplexed single-cell characterization of alternative polyadenylation regulators. Cell 2024:S0092-8674(24)00645-7. [PMID: 38925112 DOI: 10.1016/j.cell.2024.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/12/2024] [Accepted: 06/05/2024] [Indexed: 06/28/2024]
Abstract
Most mammalian genes have multiple polyA sites, representing a substantial source of transcript diversity regulated by the cleavage and polyadenylation (CPA) machinery. To better understand how these proteins govern polyA site choice, we introduce CPA-Perturb-seq, a multiplexed perturbation screen dataset of 42 CPA regulators with a 3' scRNA-seq readout that enables transcriptome-wide inference of polyA site usage. We develop a framework to detect perturbation-dependent changes in polyadenylation and characterize modules of co-regulated polyA sites. We find groups of intronic polyA sites regulated by distinct components of the nuclear RNA life cycle, including elongation, splicing, termination, and surveillance. We train and validate a deep neural network (APARENT-Perturb) for tandem polyA site usage, delineating a cis-regulatory code that predicts perturbation response and reveals interactions between regulatory complexes. Our work highlights the potential for multiplexed single-cell perturbation screens to further our understanding of post-transcriptional regulation.
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Affiliation(s)
- Madeline H Kowalski
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA; New York University Grossman School of Medicine, New York, NY, USA
| | - Hans-Hermann Wessels
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA.
| | - Johannes Linder
- Department of Genetics, Stanford University, Stanford, CA, USA; Department of Computer Science, Stanford University, Stanford, CA, USA
| | | | - Isabella Mascio
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | - Saket Choudhary
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | | | - Yuhan Hao
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA
| | - Anshul Kundaje
- Department of Genetics, Stanford University, Stanford, CA, USA; Department of Computer Science, Stanford University, Stanford, CA, USA
| | - Rahul Satija
- New York Genome Center, New York, NY, USA; Center for Genomics and Systems Biology, New York University, New York, NY, USA; New York University Grossman School of Medicine, New York, NY, USA.
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3
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Wang K, Zhang T, Li X, Zhang X, Li R, Pan B, Deng J. Identification of hub genes and potential therapeutic mechanisms related to HPV positive head and neck squamous carcinoma based on full transcriptomic detection and ceRNA network construction. Gene 2024; 910:148321. [PMID: 38428621 DOI: 10.1016/j.gene.2024.148321] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2023] [Revised: 02/21/2024] [Accepted: 02/26/2024] [Indexed: 03/03/2024]
Abstract
Infection with human papillomavirus (HPV) is a major risk factor for head and neck squamous cell carcinoma (HNSCC). The objective of this study is to investigate the gene expression profiles and signaling pathways that are specific to HPV-positive HNSCC (HPV+ HNSCC). Moreover, a competing endogenous RNA (ceRNA) network analysis was utilized to identify the core gene of HPV+ HNSCC and potential targeted therapeutic drugs. Transcriptome sequencing analysis identified 3,253 coding RNAs and 3,903 non-coding RNAs (ncRNAs) that exhibited preferentially expressed in HPV+ HNSCC. Four key signaling pathways were selected through pathway enrichment analysis. By combining ceRNA network and protein-protein interaction (PPI) network topology analysis, RNA Polymerase II Associated Protein 2 (RPAP2), which also exhibited high expression in HPV+ HNSCC based on the TCGA database, was identified as the hub gene. Gene set enrichment analysis (GSEA) results revealed RPAP2's involvement in various signaling pathways, encompassing basal transcription factors, ubiquitin-mediated proteolysis, adherens junction, other glycan degradation, ATP-binding cassette (ABC) transporters, and oglycan biosynthesis. Five potential small molecule targeted drugs (enzastaurin, brequinar, talinolol, phenylbutazone, and afuresertib) were identified using the cMAP database, with enzastaurin showing the highest affinity for RPAP2. Cellular functional experiments confirmed the inhibitory effect of enzastaurin on cell viability of HPV+ HNSCC and RPAP2 expression levels. Additionally, enzastaurin treatment suppressed the expression levels of the top-ranked long non-coding RNA (lncRNA), circular RNA (circRNA), and microRNA (miRNA) in the ceRNA network. This study based on the ceRNA network provides valuable insights into the molecular mechanisms and potential therapeutic strategies for HPV+ HNSCC, and provide theoretical basis for the exploration of HPV+ HNSCC biomarkers and the development of targeted drugs.
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Affiliation(s)
- Kunpeng Wang
- The School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, China
| | - Tingting Zhang
- The School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, China
| | - Xia Li
- The School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, China
| | - Xinran Zhang
- The School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, China
| | - Rui Li
- Department of Biochemistry and Molecular Biology, Key Laboratory of Breast Cancer Prevention and Therapy, Ministry of Education, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China.
| | - Boyu Pan
- Tianjin Medical University Cancer Institute & Hospital, National Clinical Research Center for Cancer, Key Laboratory of Cancer Prevention and Therapy, Tianjin's Clinical Research Center for Cancer, Tianjin 300060, China.
| | - Jiayin Deng
- The School and Hospital of Stomatology, Tianjin Medical University, Tianjin 300070, China.
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4
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Goldstein SI, Fan AC, Wang Z, Naineni SK, Lengqvist J, Chernobrovkin A, Garcia-Gutierrez SB, Cencic R, Patel K, Huang S, Brown LE, Emili A, Porco JA. Proteomic Discovery of RNA-Protein Molecular Clamps Using a Thermal Shift Assay with ATP and RNA (TSAR). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.19.590252. [PMID: 38659867 PMCID: PMC11042367 DOI: 10.1101/2024.04.19.590252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Uncompetitive inhibition is an effective strategy for suppressing dysregulated enzymes and their substrates, but discovery of suitable ligands depends on often-unavailable structural knowledge and serendipity. Hence, despite surging interest in mass spectrometry-based target identification, proteomic studies of substrate-dependent target engagement remain sparse. Herein, we describe the Thermal Shift Assay with ATP and RNA (TSAR) as a template for proteome-wide discovery of substrate-dependent ligand binding. Using proteomic thermal shift assays, we show that simple biochemical additives can facilitate detection of target engagement in native cell lysates. We apply our approach to rocaglates, a family of molecules that specifically clamp RNA to eukaryotic translation initiation factor 4A (eIF4A), DEAD-box helicase 3X (DDX3X), and potentially other members of the DEAD-box (DDX) family of RNA helicases. To identify unexpected interactions, we optimized a target class-specific thermal denaturation window and evaluated ATP analog and RNA probe dependencies for key rocaglate-DDX interactions. We report novel DDX targets of the rocaglate clamping spectrum, confirm that DDX3X is a common target of several widely studied analogs, and provide structural insights into divergent DDX3X affinities between synthetic rocaglates. We independently validate novel targets of high-profile rocaglates, including the clinical candidate Zotatifin (eFT226), using limited proteolysis-mass spectrometry and fluorescence polarization experiments. Taken together, our study provides a model for screening uncompetitive inhibitors using a systematic chemical-proteomics approach to uncover actionable DDX targets, clearing a path towards characterization of novel molecular clamps and associated RNA helicase targets.
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Affiliation(s)
- Stanley I. Goldstein
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
- Department of Pharmacology, Physiology, and Biophysics, Boston University, Boston, MA, USA
| | - Alice C. Fan
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Zihao Wang
- Department of Chemistry, Boston University, Boston, MA, USA
| | - Sai K. Naineni
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | | | | | | | - Regina Cencic
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Kesha Patel
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Sidong Huang
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | | | - Andrew Emili
- Knight Cancer Institute, Oregon Health and Science University, Portland, OR, USA
| | - John A. Porco
- BU Target Discovery Laboratory (BU-TDL), Boston University, Boston, MA, USA
- Department of Chemistry, Boston University, Boston, MA, USA
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5
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Frommelt F, Fossati A, Uliana F, Wendt F, Xue P, Heusel M, Wollscheid B, Aebersold R, Ciuffa R, Gstaiger M. DIP-MS: ultra-deep interaction proteomics for the deconvolution of protein complexes. Nat Methods 2024; 21:635-647. [PMID: 38532014 PMCID: PMC11009110 DOI: 10.1038/s41592-024-02211-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 02/14/2024] [Indexed: 03/28/2024]
Abstract
Most proteins are organized in macromolecular assemblies, which represent key functional units regulating and catalyzing most cellular processes. Affinity purification of the protein of interest combined with liquid chromatography coupled to tandem mass spectrometry (AP-MS) represents the method of choice to identify interacting proteins. The composition of complex isoforms concurrently present in the AP sample can, however, not be resolved from a single AP-MS experiment but requires computational inference from multiple time- and resource-intensive reciprocal AP-MS experiments. Here we introduce deep interactome profiling by mass spectrometry (DIP-MS), which combines AP with blue-native-PAGE separation, data-independent acquisition with mass spectrometry and deep-learning-based signal processing to resolve complex isoforms sharing the same bait protein in a single experiment. We applied DIP-MS to probe the organization of the human prefoldin family of complexes, resolving distinct prefoldin holo- and subcomplex variants, complex-complex interactions and complex isoforms with new subunits that were experimentally validated. Our results demonstrate that DIP-MS can reveal proteome modularity at unprecedented depth and resolution.
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Affiliation(s)
- Fabian Frommelt
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
| | - Andrea Fossati
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- Quantitative Biosciences Institute (QBI), University of California San Francisco, San Francisco, CA, USA
- Department of Cellular and Molecular Pharmacology, University of California San Francisco, San Francisco, CA, USA
- J. David Gladstone Institutes, San Francisco, CA, USA
| | - Federico Uliana
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- Department of Biology, Institute of Biochemistry, ETH Zurich, Zurich, Switzerland
| | - Fabian Wendt
- Department of Health Sciences and Technology (D-HEST), Institute of Translational Medicine (ITM), ETH Zurich, Zurich, Switzerland
| | - Peng Xue
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
- Guangzhou National Laboratory, Guang Zhou, China
| | - Moritz Heusel
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Bernd Wollscheid
- Department of Health Sciences and Technology (D-HEST), Institute of Translational Medicine (ITM), ETH Zurich, Zurich, Switzerland
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Rodolfo Ciuffa
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland
| | - Matthias Gstaiger
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, Zurich, Switzerland.
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6
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Palumbo RJ, Yang Y, Feigon J, Hanes SD. Catalytic activity of the Bin3/MePCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. Genetics 2024; 226:iyad203. [PMID: 37982586 PMCID: PMC10763541 DOI: 10.1093/genetics/iyad203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 10/27/2023] [Accepted: 11/13/2023] [Indexed: 11/21/2023] Open
Abstract
Methylphosphate Capping Enzyme (MePCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MePCE in vitro, little is known about its functions in vivo, or what roles-if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MePCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MePCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MePCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
| | - Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, CA 90095, USA
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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7
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Pinard M, Moursli A, Coulombe B. Drugs targeting the particle for arrangement of quaternary structure (PAQosome) and protein complex assembly. Expert Opin Drug Discov 2024; 19:57-71. [PMID: 37840283 DOI: 10.1080/17460441.2023.2267974] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Accepted: 10/04/2023] [Indexed: 10/17/2023]
Abstract
INTRODUCTION The PAQosome is a 12-subunit complex that acts as a co-factor of the molecular chaperones HSP90 and HSP70. This co-chaperone has been shown to participate in assembly and maturation of several protein complexes, including nuclear RNA polymerases, RNA processing factors, the ribosome, PIKKs, and others. Subunits of the PAQosome, adaptors, and clients have been reported to be involved in various diseases, making them interesting targets for drug discovery. AREA COVERED In this review, the authors cover the detailed mechanisms of PAQosome and chaperone function. Specifically, the authors summarize the status of the PAQosome and some related chaperones and co-chaperones as candidate targets for drug discovery. Indeed, a number of compounds are currently being tested for the development of treatments against diseases, such as cancers and neurodegenerative conditions. EXPERT OPINION Searching for new drugs targeting the PAQosome requires a better understanding of PAQosome subunit interactions and the discovery of new interaction partners. Thus, PAQosome subunit crystallization is an important experiment to initiate virtual screening against new target and the development of in silico tools such as AlphaFold-multimer could accelerate the search for new interaction partner and determine more rapidly the interaction pocket needed for virtual drug screening.
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Affiliation(s)
- Maxime Pinard
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Asmae Moursli
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
| | - Benoit Coulombe
- Translational Proteomics Laboratory, Institut de Recherches Cliniques de Montréal, Montréal, Québec, Canada
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
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López-Perrote A, Serna M, Llorca O. Maturation and Assembly of mTOR Complexes by the HSP90-R2TP-TTT Chaperone System: Molecular Insights and Mechanisms. Subcell Biochem 2024; 104:459-483. [PMID: 38963496 DOI: 10.1007/978-3-031-58843-3_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
The mechanistic target of rapamycin (mTOR) is a master regulator of cell growth and metabolism, integrating environmental signals to regulate anabolic and catabolic processes, regulating lipid synthesis, growth factor-induced cell proliferation, cell survival, and migration. These activities are performed as part of two distinct complexes, mTORC1 and mTORC2, each with specific roles. mTORC1 and mTORC2 are elaborated dimeric structures formed by the interaction of mTOR with specific partners. mTOR functions only as part of these large complexes, but their assembly and activation require a dedicated and sophisticated chaperone system. mTOR folding and assembly are temporarily separated with the TELO2-TTI1-TTI2 (TTT) complex assisting the cotranslational folding of mTOR into a native conformation. Matured mTOR is then transferred to the R2TP complex for assembly of active mTORC1 and mTORC2 complexes. R2TP works in concert with the HSP90 chaperone to promote the incorporation of additional subunits to mTOR and dimerization. This review summarizes our current knowledge on how the HSP90-R2TP-TTT chaperone system facilitates the maturation and assembly of active mTORC1 and mTORC2 complexes, discussing interactions, structures, and mechanisms.
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Affiliation(s)
- Andrés López-Perrote
- Spanish National Cancer Research Centre (CNIO), Structural Biology Programme, Melchor Fernández Almagro 3, Madrid, Spain.
| | - Marina Serna
- Spanish National Cancer Research Centre (CNIO), Structural Biology Programme, Melchor Fernández Almagro 3, Madrid, Spain
| | - Oscar Llorca
- Spanish National Cancer Research Centre (CNIO), Structural Biology Programme, Melchor Fernández Almagro 3, Madrid, Spain.
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9
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Peng Q, Wang Y, Xiao Y, Chang H, Luo S, Wang D, Rong YS. Drosophila Amus and Bin3 methylases functionally replace mammalian MePCE for capping and the stabilization of U6 and 7SK snRNAs. SCIENCE ADVANCES 2023; 9:eadj9359. [PMID: 38100593 PMCID: PMC10848712 DOI: 10.1126/sciadv.adj9359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/25/2023] [Accepted: 11/15/2023] [Indexed: 12/17/2023]
Abstract
U6 and 7SK snRNAs have a 5' cap, believed to be essential for their stability and maintained by mammalian MePCE or Drosophila Bin3 enzymes. Although both proteins are required for 7SK stability, loss of neither destabilizes U6, casting doubts on the function of capping U6. Here, we show that the Drosophila Amus protein, homologous to both proteins, is essential for U6 but not 7SK stability. The loss of U6 is rescued by the expression of an Amus-MePCE hybrid protein harboring the methyltransferase domain from MePCE, highlighting the conserved function of the two proteins as the U6 capping enzyme. Our investigations in human cells establish a dependence of both U6 and 7SK stability on MePCE, resolving a long-standing uncertainty. While uncovering a division of labor of Bin3/MePCE/Amus proteins, we found a "Bin3-Box" domain present only in enzymes associated with 7SK regulation. Targeted mutagenesis confirms its importance for Bin3 function, revealing a possible conserved element in 7SK but not U6 biology.
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Affiliation(s)
- Qiu Peng
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
| | - Yiqing Wang
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
| | - Ying Xiao
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
| | - Hua Chang
- School of Life Sciences, Sun Yat-sen University, Guangzhou, China
| | - Shishi Luo
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
| | - Danling Wang
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
| | - Yikang S. Rong
- MOE Key Lab of Rare Pediatric Diseases, Hengyang College of Medicine, University of South China, Hengyang, China
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Wang Y, Traugot CM, Bubenik JL, Li T, Sheng P, Hiers NM, Fernandez P, Li L, Bian J, Swanson MS, Xie M. N 6-methyladenosine in 7SK small nuclear RNA underlies RNA polymerase II transcription regulation. Mol Cell 2023; 83:3818-3834.e7. [PMID: 37820733 PMCID: PMC10873123 DOI: 10.1016/j.molcel.2023.09.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 08/07/2023] [Accepted: 09/13/2023] [Indexed: 10/13/2023]
Abstract
N6-methyladenosine (m6A) modifications play crucial roles in RNA metabolism. How m6A regulates RNA polymerase II (RNA Pol II) transcription remains unclear. We find that 7SK small nuclear RNA (snRNA), a regulator of RNA Pol II promoter-proximal pausing, is highly m6A-modified in non-small cell lung cancer (NSCLC) cells. In A549 cells, we identified eight m6A sites on 7SK and discovered methyltransferase-like 3 (METTL3) and alkB homolog 5 (ALKBH5) as the responsible writer and eraser. When the m6A-7SK is specifically erased by a dCasRx-ALKBH5 fusion protein, A549 cell growth is attenuated due to reduction of RNA Pol II transcription. Mechanistically, removal of m6A leads to 7SK structural rearrangements that facilitate sequestration of the positive transcription elongation factor b (P-TEFb) complex, which results in reduction of serine 2 phosphorylation (Ser2P) in the RNA Pol II C-terminal domain and accumulation of RNA Pol II in the promoter-proximal region. Taken together, we uncover that m6A modifications of a non-coding RNA regulate RNA Pol II transcription and NSCLC tumorigenesis.
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Affiliation(s)
- Yuzhi Wang
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Conner M Traugot
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Jodi L Bubenik
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Tianqi Li
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Peike Sheng
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Nicholas M Hiers
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Paul Fernandez
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Lu Li
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA
| | - Jiang Bian
- UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA; Department of Health Outcomes & Biomedical Informatics, University of Florida, Gainesville, FL 32610, USA
| | - Maurice S Swanson
- Department of Molecular Genetics & Microbiology, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA
| | - Mingyi Xie
- Department of Biochemistry and Molecular Biology, University of Florida, Gainesville, FL 32610, USA; UF Health Cancer Center, University of Florida, Gainesville, FL 32610, USA; UF Genetics Institute, University of Florida, Gainesville, FL 32610, USA.
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11
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Porat J, Slat VA, Rader SD, Bayfield MA. The fission yeast methyl phosphate capping enzyme Bmc1 guides 2'-O-methylation of the U6 snRNA. Nucleic Acids Res 2023; 51:8805-8819. [PMID: 37403782 PMCID: PMC10484740 DOI: 10.1093/nar/gkad563] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2023] [Revised: 06/15/2023] [Accepted: 06/23/2023] [Indexed: 07/06/2023] Open
Abstract
Splicing requires the tight coordination of dynamic spliceosomal RNAs and proteins. U6 is the only spliceosomal RNA transcribed by RNA Polymerase III and undergoes an extensive maturation process. In humans and fission yeast, this includes addition of a 5' γ-monomethyl phosphate cap by members of the Bin3/MePCE family as well as snoRNA guided 2'-O-methylation. Previously, we have shown that the Bin3/MePCE homolog Bmc1 is recruited to the S. pombe telomerase holoenzyme by the LARP7 family protein Pof8, where it acts in a catalytic-independent manner to protect the telomerase RNA and facilitate holoenzyme assembly. Here, we show that Bmc1 and Pof8 are required for the formation of a distinct U6 snRNP that promotes 2'-O-methylation of U6, and identify a non-canonical snoRNA that guides this methylation. We also show that the 5' γ-monomethyl phosphate capping activity of Bmc1 is not required for its role in promoting snoRNA guided 2'-O-methylation, and that this role relies on different regions of Pof8 from those required for Pof8 function in telomerase. Our results are consistent with a novel role for Bmc1/MePCE family members in stimulating 2'-O-methylation and a more general role for Bmc1 and Pof8 in guiding noncoding RNP assembly beyond the telomerase RNP.
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Affiliation(s)
| | - Viktor A Slat
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
| | - Stephen D Rader
- Department of Biochemistry and Molecular Biology, University of British Columbia, Vancouver, Canada
- Department of Chemistry and Biochemistry, University of Northern British Columbia, Prince George, Canada
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12
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Zhou S, Van Bortle K. The Pol III transcriptome: Basic features, recurrent patterns, and emerging roles in cancer. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 14:e1782. [PMID: 36754845 PMCID: PMC10498592 DOI: 10.1002/wrna.1782] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Revised: 01/13/2023] [Accepted: 01/18/2023] [Indexed: 02/10/2023]
Abstract
The RNA polymerase III (Pol III) transcriptome is universally comprised of short, highly structured noncoding RNA (ncRNA). Through RNA-protein interactions, the Pol III transcriptome actuates functional activities ranging from nuclear gene regulation (7SK), splicing (U6, U6atac), and RNA maturation and stability (RMRP, RPPH1, Y RNA), to cytoplasmic protein targeting (7SL) and translation (tRNA, 5S rRNA). In higher eukaryotes, the Pol III transcriptome has expanded to include additional, recently evolved ncRNA species that effectively broaden the footprint of Pol III transcription to additional cellular activities. Newly evolved ncRNAs function as riboregulators of autophagy (vault), immune signaling cascades (nc886), and translation (Alu, BC200, snaR). Notably, upregulation of Pol III transcription is frequently observed in cancer, and multiple ncRNA species are linked to both cancer progression and poor survival outcomes among cancer patients. In this review, we outline the basic features and functions of the Pol III transcriptome, and the evidence for dysregulation and dysfunction for each ncRNA in cancer. When taken together, recurrent patterns emerge, ranging from shared functional motifs that include molecular scaffolding and protein sequestration, overlapping protein interactions, and immunostimulatory activities, to the biogenesis of analogous small RNA fragments and noncanonical miRNAs, augmenting the function of the Pol III transcriptome and further broadening its role in cancer. This article is categorized under: RNA in Disease and Development > RNA in Disease RNA Processing > Processing of Small RNAs RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications.
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Affiliation(s)
- Sihang Zhou
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
| | - Kevin Van Bortle
- Department of Cell and Developmental Biology, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
- Cancer Center at Illinois, University of Illinois Urbana-Champaign, Urbana, Illinois, USA
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13
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Palumbo RJ, Hanes SD. Catalytic activity of the Bin3/MEPCE methyltransferase domain is dispensable for 7SK snRNP function in Drosophila melanogaster. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.01.543302. [PMID: 37333392 PMCID: PMC10274667 DOI: 10.1101/2023.06.01.543302] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Methylphosphate Capping Enzyme (MEPCE) monomethylates the gamma phosphate at the 5' end of the 7SK noncoding RNA, a modification thought to protect 7SK from degradation. 7SK serves as a scaffold for assembly of a snRNP complex that inhibits transcription by sequestering the positive elongation factor P-TEFb. While much is known about the biochemical activity of MEPCE in vitro, little is known about its functions in vivo, or what roles- if any-there are for regions outside the conserved methyltransferase domain. Here, we investigated the role of Bin3, the Drosophila ortholog of MEPCE, and its conserved functional domains in Drosophila development. We found that bin3 mutant females had strongly reduced rates of egg-laying, which was rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 promotes fecundity by repressing P-TEFb. bin3 mutants also exhibited neuromuscular defects, analogous to a patient with MEPCE haploinsufficiency. These defects were also rescued by genetic reduction of P-TEFb activity, suggesting that Bin3 and MEPCE have conserved roles in promoting neuromuscular function by repressing P-TEFb. Unexpectedly, we found that a Bin3 catalytic mutant (Bin3Y795A) could still bind and stabilize 7SK and rescue all bin3 mutant phenotypes, indicating that Bin3 catalytic activity is dispensable for 7SK stability and snRNP function in vivo. Finally, we identified a metazoan-specific motif (MSM) outside of the methyltransferase domain and generated mutant flies lacking this motif (Bin3ΔMSM). Bin3ΔMSM mutant flies exhibited some-but not all-bin3 mutant phenotypes, suggesting that the MSM is required for a 7SK-independent, tissue-specific function of Bin3.
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Affiliation(s)
- Ryan J Palumbo
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
| | - Steven D Hanes
- Department of Biochemistry & Molecular Biology, SUNY Upstate Medical University 750 East Adams Street, 4283 Weiskotten Hall, Syracuse, New York, 13210
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14
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Camara MB, Sobeh AM, Eichhorn CD. Progress in 7SK ribonucleoprotein structural biology. Front Mol Biosci 2023; 10:1154622. [PMID: 37051324 PMCID: PMC10083321 DOI: 10.3389/fmolb.2023.1154622] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/16/2023] [Indexed: 03/29/2023] Open
Abstract
The 7SK ribonucleoprotein (RNP) is a dynamic and multifunctional regulator of RNA Polymerase II (RNAPII) transcription in metazoa. Comprised of the non-coding 7SK RNA, core proteins, and numerous accessory proteins, the most well-known 7SK RNP function is the sequestration and inactivation of the positive transcription elongation factor b (P-TEFb). More recently, 7SK RNP has been shown to regulate RNAPII transcription through P-TEFb-independent pathways. Due to its fundamental role in cellular function, dysregulation has been linked with human diseases including cancers, heart disease, developmental disorders, and viral infection. Significant advances in 7SK RNP structural biology have improved our understanding of 7SK RNP assembly and function. Here, we review progress in understanding the structural basis of 7SK RNA folding, biogenesis, and RNP assembly.
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Affiliation(s)
- Momodou B. Camara
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Amr M. Sobeh
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
| | - Catherine D. Eichhorn
- Department of Chemistry, University of Nebraska, Lincoln, NE, United States
- Nebraska Center for Integrated Biomolecular Communication, Lincoln, NE, United States
- *Correspondence: Catherine D. Eichhorn,
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15
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Kamal AHM, Chakrabarty JK, Chowdhury SM. Lipopolysaccharide and statin-mediated immune-responsive protein networks revealed in macrophages through affinity purification spacer-arm controlled cross-linking (AP-SPACC) proteomics. Mol Omics 2023; 19:48-59. [PMID: 36377691 DOI: 10.1039/d2mo00224h] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Toll-like receptor 4 (TLR4), a pattern recognition receptor, is activated by lipopolysaccharides (LPS) and induces the MyD88 pathway, which subsequently produces pro-inflammatory cytokines through activation of transcriptional nuclear factor (NF)-κB. Statins have been widely prescribed to reduce cholesterol synthesis for patients with cardiovascular disease. Statins may have pleiotropic effects, which include anti- and pro-inflammatory effects on cells. The molecular mechanism of the sequential influence of LPS and statin on the innate immune system remains unknown. We employed affinity purification-spacer-arm controlled cross-linking (AP-SPACC) MS-based proteomics analysis to identify the LPS- and statin-LPS-responsive proteins and their networks. LPS-stimulated RAW 264.7 macrophage cells singly and combined with the drug statin used in this study. Two chemical cross-linkers with different spacer chain lengths were utilized to stabilize the weak and transient interactors. Proteomic analysis identified 1631 differentially expressed proteins. We identified 151 immune-response proteins through functional enrichment analysis and visualized their interaction networks. Selected candidate protein-coding genes were validated, specifically squamous cell carcinoma antigens recognized by T cells 3, sphingosine-1-phosphate lyase 1, Ras-related protein Rab-35, and tumor protein D52 protein-coding genes through transcript-level expression analysis. The expressions of those genes were significantly increased upon statin treatment and decreased in LPS-stimulated macrophage cells. Therefore, we presumed that the expression changes of genes occurred due to immune response during activation of inflammation. These results highlight the immune-responsive proteins network, providing a new platform for novel investigations and discovering future therapeutic targets for inflammatory diseases.
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Affiliation(s)
- Abu Hena Mostafa Kamal
- Department of Chemistry and Biochemistry, University of Texas at Arlington, TX, 76019, USA. .,Advanced Technology Cores, Dan L Duncan Comprehensive Cancer Center, Metabolomics Core, Baylor College of Medicine, Houston, TX, 77030, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Jayanta K Chakrabarty
- Department of Chemistry and Biochemistry, University of Texas at Arlington, TX, 76019, USA. .,Quantitative Proteomics and Metabolomics Center, Columbia University, New York, NY, 10027, USA
| | - Saiful M Chowdhury
- Department of Chemistry and Biochemistry, University of Texas at Arlington, TX, 76019, USA.
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16
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Klimešová K, Petržílková H, Bařinka C, Staněk D. SART3 associates with a post-splicing complex. J Cell Sci 2023; 136:jcs260380. [PMID: 36620952 DOI: 10.1242/jcs.260380] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 12/10/2022] [Indexed: 01/10/2023] Open
Abstract
SART3 is a multifunctional protein that acts in several steps of gene expression, including assembly and recycling of the spliceosomal U4/U6 small nuclear ribonucleoprotein particle (snRNP). In this work, we provide evidence that SART3 associates via its N-terminal HAT domain with the 12S U2 snRNP. Further analysis showed that SART3 associates with the post-splicing complex containing U2 and U5 snRNP components. In addition, we observed an interaction between SART3 and the RNA helicase DHX15, which disassembles post-splicing complexes. Based on our data, we propose a model that SART3 associates via its N-terminal HAT domain with the post-splicing complex, where it interacts with U6 snRNA to protect it and to initiate U6 snRNA recycling before a next round of splicing.
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MESH Headings
- RNA Splicing/genetics
- Spliceosomes/genetics
- Spliceosomes/metabolism
- RNA, Small Nuclear/genetics
- RNA, Small Nuclear/metabolism
- Ribonucleoprotein, U4-U6 Small Nuclear/genetics
- Ribonucleoprotein, U4-U6 Small Nuclear/metabolism
- Ribonucleoprotein, U5 Small Nuclear/genetics
- Ribonucleoprotein, U5 Small Nuclear/metabolism
- Ribonucleoprotein, U2 Small Nuclear/genetics
- Ribonucleoprotein, U2 Small Nuclear/metabolism
- Ribonucleoproteins, Small Nuclear/genetics
- Ribonucleoproteins, Small Nuclear/metabolism
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Affiliation(s)
- Klára Klimešová
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Hana Petržílková
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
| | - Cyril Bařinka
- Laboratory of Structural Biology, Institute of Biotechnology, Czech Academy of Sciences, 252 50 Prague, Czech Republic
| | - David Staněk
- Department of RNA Biology, Institute of Molecular Genetics, Czech Academy of Sciences, 142 20 Prague, Czech Republic
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17
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The Role of Hsp90-R2TP in Macromolecular Complex Assembly and Stabilization. Biomolecules 2022; 12:biom12081045. [PMID: 36008939 PMCID: PMC9406135 DOI: 10.3390/biom12081045] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 07/19/2022] [Accepted: 07/25/2022] [Indexed: 01/27/2023] Open
Abstract
Hsp90 is a ubiquitous molecular chaperone involved in many cell signaling pathways, and its interactions with specific chaperones and cochaperones determines which client proteins to fold. Hsp90 has been shown to be involved in the promotion and maintenance of proper protein complex assembly either alone or in association with other chaperones such as the R2TP chaperone complex. Hsp90-R2TP acts through several mechanisms, such as by controlling the transcription of protein complex subunits, stabilizing protein subcomplexes before their incorporation into the entire complex, and by recruiting adaptors that facilitate complex assembly. Despite its many roles in protein complex assembly, detailed mechanisms of how Hsp90-R2TP assembles protein complexes have yet to be determined, with most findings restricted to proteomic analyses and in vitro interactions. This review will discuss our current understanding of the function of Hsp90-R2TP in the assembly, stabilization, and activity of the following seven classes of protein complexes: L7Ae snoRNPs, spliceosome snRNPs, RNA polymerases, PIKKs, MRN, TSC, and axonemal dynein arms.
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18
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Yang Y, Liu S, Egloff S, Eichhorn CD, Hadjian T, Zhen J, Kiss T, Zhou ZH, Feigon J. Structural basis of RNA conformational switching in the transcriptional regulator 7SK RNP. Mol Cell 2022; 82:1724-1736.e7. [PMID: 35320752 PMCID: PMC9081187 DOI: 10.1016/j.molcel.2022.03.001] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Revised: 12/27/2021] [Accepted: 02/28/2022] [Indexed: 01/05/2023]
Abstract
7SK non-coding RNA (7SK) negatively regulates RNA polymerase II (RNA Pol II) elongation by inhibiting positive transcription elongation factor b (P-TEFb), and its ribonucleoprotein complex (RNP) is hijacked by HIV-1 for viral transcription and replication. Methylphosphate capping enzyme (MePCE) and La-related protein 7 (Larp7) constitutively associate with 7SK to form a core RNP, while P-TEFb and other proteins dynamically assemble to form different complexes. Here, we present the cryo-EM structures of 7SK core RNP formed with two 7SK conformations, circular and linear, and uncover a common RNA-dependent MePCE-Larp7 complex. Together with NMR, biochemical, and cellular data, these structures reveal the mechanism of MePCE catalytic inactivation in the core RNP, unexpected interactions between Larp7 and RNA that facilitate a role as an RNP chaperone, and that MePCE-7SK-Larp7 core RNP serves as a scaffold for switching between different 7SK conformations essential for RNP assembly and regulation of P-TEFb sequestration and release.
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Affiliation(s)
- Yuan Yang
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Shiheng Liu
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Sylvain Egloff
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France
| | - Catherine D Eichhorn
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tanya Hadjian
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - James Zhen
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA
| | - Tamás Kiss
- Molecular, Cellular, and Developmental Biology Department (MCD), Centre de Biologie Intégrative (CBI), University of Toulouse, CNRS, UPS, 31062 Toulouse, France; Biological Research Centre, Szeged, Temesvári krt. 62, 6726, Hungary
| | - Z Hong Zhou
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, Los Angeles, CA 90095, USA; California NanoSystems Institute, University of California, Los Angeles, Los Angeles, CA 90095, USA.
| | - Juli Feigon
- Department of Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA 90095, USA.
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19
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Ling X, Wu W, Aljahdali IAM, Liao J, Santha S, Fountzilas C, Boland PM, Li F. FL118, acting as a 'molecular glue degrader', binds to dephosphorylates and degrades the oncoprotein DDX5 (p68) to control c-Myc, survivin and mutant Kras against colorectal and pancreatic cancer with high efficacy. Clin Transl Med 2022; 12:e881. [PMID: 35604033 PMCID: PMC9126027 DOI: 10.1002/ctm2.881] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 04/26/2022] [Accepted: 05/03/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Pancreatic ductal adenocarcinoma (PDAC), a difficult-to-treat cancer, is expected to become the second-largest cause of cancer-related deaths by 2030, while colorectal cancer (CRC) is the third most common cancer and the third leading cause of cancer deaths. Currently, there is no effective treatment for PDAC patients. The development of novel agents to effectively treat these cancers remains an unmet clinical need. FL118, a novel anticancer small molecule, exhibits high efficacy against cancers; however, the direct biochemical target of FL118 is unknown. METHODS FL118 affinity purification, mass spectrometry, Nanosep centrifugal device and isothermal titration calorimetry were used for identifying and confirming FL118 binding to DDX5/p68 and its binding affinity. Immunoprecipitation (IP), western blots, real-time reverse transcription PCR, gene silencing, overexpression (OE) and knockout (KO) were used for analysing gene/protein function and expression. Chromatin IP was used for analysing protein-DNA interactions. The 3-[4,5-dimethylthiazol-2-yl]-2,5-diphenyltetrazolium bromid assay and human PDAC/CRC cell/tumour models were used for determining PDAC/CRC cell/tumour in vitro and in vivo growth. RESULTS We discovered that FL118 strongly binds to dephosphorylates and degrades the DDX5 oncoprotein via the proteasome degradation pathway without decreasing DDX5 mRNA. Silencing and OE of DDX5 indicated that DDX5 is a master regulator for controlling the expression of multiple oncogenic proteins, including survivin, Mcl-1, XIAP, cIAP2, c-Myc and mutant Kras. Genetic manipulation of DDX5 in PDAC cells affects tumour growth. PDAC cells with DDX5 KO are resistant to FL118 treatment. Our human tumour animal model studies further indicated that FL118 exhibits high efficacy to eliminate human PDAC and CRC tumours that have a high expression of DDX5, while FL118 exhibits less effectiveness in PDAC and CRC tumours with low DDX5 expression. CONCLUSION DDX5 is a bona fide FL118 direct target and can act as a biomarker for predicting PDAC and CRC tumour sensitivity to FL118. This would greatly impact FL118 precision medicine for patients with advanced PDAC or advanced CRC in the clinic. FL118 may act as a 'molecular glue degrader' to directly glue DDX5 and ubiquitination regulators together to degrade DDX5.
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Affiliation(s)
- Xiang Ling
- Department of Pharmacology & TherapeuticsRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Canget BioTekpharma LLCBuffaloNew YorkUSA
| | - Wenjie Wu
- Department of Pharmacology & TherapeuticsRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Canget BioTekpharma LLCBuffaloNew YorkUSA
| | - Ieman A. M. Aljahdali
- Department of Pharmacology & TherapeuticsRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Department of Cellular & Molecular BiologyRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
| | | | | | - Christos Fountzilas
- Department of MedicineRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Developmental Therapeutics (DT) ProgramRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
| | - Patrick M. Boland
- Department of MedicineRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Present address:
Development of Medical Oncology, Rutgers Cancer Institute of New Jersey, The State University of New Jersey, New Brunswick, NJ 08903, USA
| | - Fengzhi Li
- Department of Pharmacology & TherapeuticsRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
- Developmental Therapeutics (DT) ProgramRoswell Park Comprehensive Cancer CenterBuffaloNew YorkUSA
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20
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Olson SW, Turner AMW, Arney JW, Saleem I, Weidmann CA, Margolis DM, Weeks KM, Mustoe AM. Discovery of a large-scale, cell-state-responsive allosteric switch in the 7SK RNA using DANCE-MaP. Mol Cell 2022; 82:1708-1723.e10. [PMID: 35320755 PMCID: PMC9081252 DOI: 10.1016/j.molcel.2022.02.009] [Citation(s) in RCA: 27] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 11/29/2021] [Accepted: 02/02/2022] [Indexed: 12/17/2022]
Abstract
7SK is a conserved noncoding RNA that regulates transcription by sequestering the transcription factor P-TEFb. 7SK function entails complex changes in RNA structure, but characterizing RNA dynamics in cells remains an unsolved challenge. We developed a single-molecule chemical probing strategy, DANCE-MaP (deconvolution and annotation of ribonucleic conformational ensembles), that defines per-nucleotide reactivity, direct base pairing interactions, tertiary interactions, and thermodynamic populations for each state in RNA structural ensembles from a single experiment. DANCE-MaP reveals that 7SK RNA encodes a large-scale structural switch that couples dissolution of the P-TEFb binding site to structural remodeling at distal release factor binding sites. The 7SK structural equilibrium shifts in response to cell growth and stress and can be targeted to modulate expression of P-TEFbresponsive genes. Our study reveals that RNA structural dynamics underlie 7SK function as an integrator of diverse cellular signals to control transcription and establishes the power of DANCE-MaP to define RNA dynamics in cells.
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Affiliation(s)
- Samuel W Olson
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Anne-Marie W Turner
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; UNC HIV Cure Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - J Winston Arney
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - Irfana Saleem
- Verna and Marrs McClean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center (THINC), Baylor College of Medicine, Houston, TX 77030, USA
| | - Chase A Weidmann
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA
| | - David M Margolis
- Department of Medicine, University of North Carolina, Chapel Hill, NC 27599, USA; UNC HIV Cure Center, University of North Carolina, Chapel Hill, NC 27599, USA
| | - Kevin M Weeks
- Department of Chemistry, University of North Carolina, Chapel Hill, NC 27599-3290, USA.
| | - Anthony M Mustoe
- Verna and Marrs McClean Department of Biochemistry and Molecular Biology, Therapeutic Innovation Center (THINC), Baylor College of Medicine, Houston, TX 77030, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX 77030, USA.
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21
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The methyl phosphate capping enzyme Bmc1/Bin3 is a stable component of the fission yeast telomerase holoenzyme. Nat Commun 2022; 13:1277. [PMID: 35277511 PMCID: PMC8917221 DOI: 10.1038/s41467-022-28985-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 02/11/2022] [Indexed: 12/13/2022] Open
Abstract
The telomerase holoenzyme is critical for maintaining eukaryotic genome integrity. In addition to a reverse transcriptase and an RNA template, telomerase contains additional proteins that protect the telomerase RNA and promote holoenzyme assembly. Here we report that the methyl phosphate capping enzyme (MePCE) Bmc1/Bin3 is a stable component of the S. pombe telomerase holoenzyme. Bmc1 associates with the telomerase holoenzyme and U6 snRNA through an interaction with the recently described LARP7 family member Pof8, and we demonstrate that these two factors are evolutionarily linked in fungi. Our data suggest that the association of Bmc1 with telomerase is independent of its methyltransferase activity, but rather that Bmc1 functions in telomerase holoenzyme assembly by promoting TER1 accumulation and Pof8 recruitment to TER1. Taken together, this work yields new insight into the composition, assembly, and regulation of the telomerase holoenzyme in fission yeast as well as the breadth of its evolutionary conservation.
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22
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A putative cap binding protein and the methyl phosphate capping enzyme Bin3/MePCE function in telomerase biogenesis. Nat Commun 2022; 13:1067. [PMID: 35217638 PMCID: PMC8881624 DOI: 10.1038/s41467-022-28545-9] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 01/13/2022] [Indexed: 01/29/2023] Open
Abstract
Telomerase reverse transcriptase (TERT) and the noncoding telomerase RNA (TR) subunit constitute the core of telomerase. Additional subunits are required for ribonucleoprotein complex assembly and in some cases remain stably associated with the active holoenzyme. Pof8, a member of the LARP7 protein family is such a constitutive component of telomerase in fission yeast. Using affinity purification of Pof8, we have identified two previously uncharacterized proteins that form a complex with Pof8 and participate in telomerase biogenesis. Both proteins participate in ribonucleoprotein complex assembly and are required for wildtype telomerase activity and telomere length maintenance. One factor we named Thc1 (Telomerase Holoenzyme Component 1) shares structural similarity with the nuclear cap binding complex and the poly-adenosine ribonuclease (PARN), the other is the ortholog of the methyl phosphate capping enzyme (Bin3/MePCE) in metazoans and was named Bmc1 (Bin3/MePCE 1) to reflect its evolutionary roots. Thc1 and Bmc1 function together with Pof8 in recognizing correctly folded telomerase RNA and promoting the recruitment of the Lsm2-8 complex and the catalytic subunit to assemble functional telomerase. Most eukaryotes maintain telomeres using a specialized reverse transcriptase. Here the authors report that Thc1 (Telomerase Holoenzyme Component 1) and Bmc1 (Bin3/MePCE 1) form a complex with Pof8, a constitutive member of telomerase in fission yeast.
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23
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The Novel Protease Activities of JMJD5–JMJD6–JMJD7 and Arginine Methylation Activities of Arginine Methyltransferases Are Likely Coupled. Biomolecules 2022; 12:biom12030347. [PMID: 35327545 PMCID: PMC8945206 DOI: 10.3390/biom12030347] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 02/03/2022] [Accepted: 02/18/2022] [Indexed: 12/23/2022] Open
Abstract
The surreptitious discoveries of the protease activities on arginine-methylated targets of a subfamily of Jumonji domain-containing family including JMJD5, JMJD6, and JMJD7 pose several questions regarding their authenticity, function, purpose, and relations with others. At the same time, despite several decades of efforts and massive accumulating data regarding the roles of the arginine methyltransferase family (PRMTs), the exact function of this protein family still remains a mystery, though it seems to play critical roles in transcription regulation, including activation and inactivation of a large group of genes, as well as other biological activities. In this review, we aim to elucidate that the function of JMJD5/6/7 and PRMTs are likely coupled. Besides roles in the regulation of the biogenesis of membrane-less organelles in cells, they are major players in regulating stimulating transcription factors to control the activities of RNA Polymerase II in higher eukaryotes, especially in the animal kingdom. Furthermore, we propose that arginine methylation by PRMTs could be a ubiquitous action marked for destruction after missions by a subfamily of the Jumonji protein family.
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Garrido-Godino AI, Cuevas-Bermúdez A, Gutiérrez-Santiago F, Mota-Trujillo MDC, Navarro F. The Association of Rpb4 with RNA Polymerase II Depends on CTD Ser5P Phosphatase Rtr1 and Influences mRNA Decay in Saccharomyces cerevisiae. Int J Mol Sci 2022; 23:ijms23042002. [PMID: 35216121 PMCID: PMC8875030 DOI: 10.3390/ijms23042002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Revised: 02/03/2022] [Accepted: 02/07/2022] [Indexed: 02/04/2023] Open
Abstract
Rtr1 is an RNA polymerase II (RNA pol II) CTD-phosphatase that influences gene expression during the transition from transcription initiation to elongation and during transcription termination. Rtr1 interacts with the RNA pol II and this interaction depends on the phosphorylation state of the CTD of Rpb1, which may influence dissociation of the heterodimer Rpb4/7 during transcription. In addition, Rtr1 was proposed as an RNA pol II import factor in RNA pol II biogenesis and participates in mRNA decay by autoregulating the turnover of its own mRNA. Our work shows that Rtr1 acts in RNA pol II assembly by mediating the Rpb4/7 association with the rest of the enzyme. RTR1 deletion alters RNA pol II assembly and increases the amount of RNA pol II associated with the chromatin that lacks Rpb4, decreasing Rpb4-mRNA imprinting and, consequently, increasing mRNA stability. Thus, Rtr1 interplays RNA pol II biogenesis and mRNA decay regulation. Our data also indicate that Rtr1 mediates mRNA decay regulation more broadly than previously proposed by cooperating with Rpb4. Interestingly, our data include new layers in the mechanisms of gene regulation and in the crosstalk between mRNA synthesis and decay by demonstrating how the association of Rpb4/7 to the RNA pol II influences mRNA decay.
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Affiliation(s)
- Ana I. Garrido-Godino
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Abel Cuevas-Bermúdez
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Francisco Gutiérrez-Santiago
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Maria del Carmen Mota-Trujillo
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
| | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain; (A.I.G.-G.); (A.C.-B.); (F.G.-S.); (M.d.C.M.-T.)
- Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Paraje de las Lagunillas, s/n, E-23071 Jaén, Spain
- Correspondence: ; Tel.: +34-953-212-771; Fax: +34-953-211-875
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Liu Y, Li L, Timani K, White C, He JJ. Tip110 Expression Facilitates the Release of HEXIM1 and pTEFb from the 7SK Ribonucleoprotein Complex Involving Regulation of the Intracellular Redox Level. Aging Dis 2021; 12:2113-2124. [PMID: 34881089 PMCID: PMC8612609 DOI: 10.14336/ad.2021.0528] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Accepted: 05/28/2021] [Indexed: 11/18/2022] Open
Abstract
HIV-1 Tat-interacting protein of 110 kDa (Tip110; p110nrb/SART3) has been identified to be important for HIV gene transcription and several host gene expression. In this study, we showed that Tip110 was present in the 7SK snRNP through direct binding to MEPCE, a component of the 7SK snRNP complex. In addition, we found a positive association between Tip110 expression, change of HEXIM1 from dimer/oligomer to monomer, and release of HEXIM1 and P-TEFb from the 7SK snRNP complex. A similar association was also noted specifically in nuclear matrix as well as in chromatin where the free HEXIM1 and 7SK snRNP-bound HEXIM1 are located. Moreover, we demonstrated that Tip110 expression was linked to the glutathione metabolic pathway and the intracellular redox level, which in turn regulated HEXIM1 dimerization/oligomerization. Lastly, we performed the FRET microscopic analysis and confirmed the direct relationship between Tip110 expression and HEXIM1 dimerization/oligomerization in vivo. Taken together, these results identified a new mechanism governing HEXIM1 dimerization/oligomerization and the release of HEXIM1 and P-TEFb from the 7SK snRNP complex. These results also yield new insights to the roles of Tip110 in HIV gene transcription and replication.
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Affiliation(s)
- Ying Liu
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Lu Li
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Khalid Timani
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
| | - Carl White
- 2Center for Cancer Cell Biology, Immunology and Infection, and.,3Department of Physiology and Biophysics, Rosalind Franklin University of Medicine and Science Chicago Medical School, 3333 Green Bay Road, North Chicago, IL 60064, USA
| | - Johnny J He
- 1Department of Microbiology and Immunology.,2Center for Cancer Cell Biology, Immunology and Infection, and
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Xu X, Mann M, Qiao D, Li Y, Zhou J, Brasier AR. Bromodomain Containing Protein 4 (BRD4) Regulates Expression of its Interacting Coactivators in the Innate Response to Respiratory Syncytial Virus. Front Mol Biosci 2021; 8:728661. [PMID: 34765643 PMCID: PMC8577543 DOI: 10.3389/fmolb.2021.728661] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Accepted: 09/24/2021] [Indexed: 12/12/2022] Open
Abstract
Bromodomain-containing protein 4 plays a central role in coordinating the complex epigenetic component of the innate immune response. Previous studies implicated BRD4 as a component of a chromatin-modifying complex that is dynamically recruited to a network of protective cytokines by binding activated transcription factors, polymerases, and histones to trigger their rapid expression via transcriptional elongation. Our previous study extended our understanding of the airway epithelial BRD4 interactome by identifying over 100 functionally important coactivators and transcription factors, whose association is induced by respiratory syncytial virus (RSV) infection. RSV is an etiological agent of recurrent respiratory tract infections associated with exacerbations of chronic obstructive pulmonary disease. Using a highly selective small-molecule BRD4 inhibitor (ZL0454) developed by us, we extend these findings to identify the gene regulatory network dependent on BRD4 bromodomain (BD) interactions. Human small airway epithelial cells were infected in the absence or presence of ZL0454, and gene expression profiling was performed. A highly reproducible dataset was obtained which indicated that BRD4 mediates both activation and repression of RSV-inducible gene regulatory networks controlling cytokine expression, interferon (IFN) production, and extracellular matrix remodeling. Index genes of functionally significant clusters were validated independently. We discover that BRD4 regulates the expression of its own gene during the innate immune response. Interestingly, BRD4 activates the expression of NFκB/RelA, a coactivator that binds to BRD4 in a BD-dependent manner. We extend this finding to show that BRD4 also regulates other components of its functional interactome, including the Mediator (Med) coactivator complex and the SWI/SNF-related, matrix-associated, actin-dependent regulator of chromatin (SMARC) subunits. To provide further insight into mechanisms for BRD4 in RSV expression, we mapped 7,845 RSV-inducible Tn5 transposase peaks onto the BRD4-dependent gene bodies. These were located in promoters and introns of cytostructural and extracellular matrix (ECM) formation genes. These data indicate that BRD4 mediates the dynamic response of airway epithelial cells to RNA infection by modulating the expression of its coactivators, controlling the expression of host defense mechanisms and remodeling genes through changes in promoter accessibility.
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Affiliation(s)
- Xiaofang Xu
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Morgan Mann
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Dianhua Qiao
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States
| | - Yi Li
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Jia Zhou
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX, United States
| | - Allan R Brasier
- Department of Medicine, University of Wisconsin-Madison School of Medicine and Public Health (SMPH), Madison, WI, United States.,Institute for Clinical and Translational Research (ICTR), University of Wisconsin-Madison, Madison, WI, United States
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Covelo-Molares H, Obrdlik A, Poštulková I, Dohnálková M, Gregorová P, Ganji R, Potěšil D, Gawriyski L, Varjosalo M, Vaňáčová Š. The comprehensive interactomes of human adenosine RNA methyltransferases and demethylases reveal distinct functional and regulatory features. Nucleic Acids Res 2021; 49:10895-10910. [PMID: 34634806 PMCID: PMC8565353 DOI: 10.1093/nar/gkab900] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2020] [Revised: 09/18/2021] [Accepted: 09/22/2021] [Indexed: 12/26/2022] Open
Abstract
N6-methyladenosine (m6A) and N6,2′-O-dimethyladenosine (m6Am) are two abundant modifications found in mRNAs and ncRNAs that can regulate multiple aspects of RNA biology. They function mainly by regulating interactions with specific RNA-binding proteins. Both modifications are linked to development, disease and stress response. To date, three methyltransferases and two demethylases have been identified that modify adenosines in mammalian mRNAs. Here, we present a comprehensive analysis of the interactomes of these enzymes. PCIF1 protein network comprises mostly factors involved in nascent RNA synthesis by RNA polymerase II, whereas ALKBH5 is closely linked with most aspects of pre-mRNA processing and mRNA export to the cytoplasm. METTL16 resides in subcellular compartments co-inhabited by several other RNA modifiers and processing factors. FTO interactome positions this demethylase at a crossroad between RNA transcription, RNA processing and DNA replication and repair. Altogether, these enzymes share limited spatial interactomes, pointing to specific molecular mechanisms of their regulation.
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Affiliation(s)
- Helena Covelo-Molares
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Ales Obrdlik
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Ivana Poštulková
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Michaela Dohnálková
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Pavlína Gregorová
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Ranjani Ganji
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - David Potěšil
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
| | - Lisa Gawriyski
- Institute of Biotechnology & HiLIFE - Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Markku Varjosalo
- Institute of Biotechnology & HiLIFE - Helsinki Institute of Life Science, University of Helsinki, Helsinki 00014, Finland
| | - Štěpánka Vaňáčová
- Central European Institute of Technology (CEITEC), Masaryk University, Brno 62500, Czech Republic
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Isa NF, Bensaude O, Aziz NC, Murphy S. HSV-1 ICP22 Is a Selective Viral Repressor of Cellular RNA Polymerase II-Mediated Transcription Elongation. Vaccines (Basel) 2021; 9:1054. [PMID: 34696162 PMCID: PMC8539892 DOI: 10.3390/vaccines9101054] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/09/2021] [Accepted: 09/13/2021] [Indexed: 11/16/2022] Open
Abstract
The Herpes Simplex Virus (HSV-1) immediate-early protein ICP22 interacts with cellular proteins to inhibit host cell gene expression and promote viral gene expression. ICP22 inhibits phosphorylation of Ser2 of the RNA polymerase II (pol II) carboxyl-terminal domain (CTD) and productive elongation of pol II. Here we show that ICP22 affects elongation of pol II through both the early-elongation checkpoint and the poly(A)-associated elongation checkpoint of a protein-coding gene model. Coimmunoprecipitation assays using tagged ICP22 expressed in human cells and pulldown assays with recombinant ICP22 in vitro coupled with mass spectrometry identify transcription elongation factors, including P-TEFb, additional CTD kinases and the FACT complex as interacting cellular factors. Using a photoreactive amino acid incorporated into ICP22, we found that L191, Y230 and C225 crosslink to both subunits of the FACT complex in cells. Our findings indicate that ICP22 interacts with critical elongation regulators to inhibit transcription elongation of cellular genes, which may be vital for HSV-1 pathogenesis. We also show that the HSV viral activator, VP16, has a region of structural similarity to the ICP22 region that interacts with elongation factors, suggesting a model where VP16 competes with ICP22 to deliver elongation factors to viral genes.
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Affiliation(s)
- Nur Firdaus Isa
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
- Research Unit for Bioinformatics and Computational Biology, Department of Biotechnology, Kulliyyah of Science, International Islamic University Malaysia, Kuantan 25200, Pahang, Malaysia;
| | - Olivier Bensaude
- Ecole Normale Supérieure, Institut de Biologie de l’Ecole Normale Supérieure, PSL Research University, CNRS UMR 8197, INSERM U 1024, F-75005 Paris, France;
| | - Nadiah C. Aziz
- Research Unit for Bioinformatics and Computational Biology, Department of Biotechnology, Kulliyyah of Science, International Islamic University Malaysia, Kuantan 25200, Pahang, Malaysia;
| | - Shona Murphy
- Sir William Dunn School of Pathology, University of Oxford, Oxford OX1 3RE, UK
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Nguyen D, Buisine N, Fayol O, Michels AA, Bensaude O, Price DH, Uguen P. An alternative D. melanogaster 7SK snRNP. BMC Mol Cell Biol 2021; 22:43. [PMID: 34461828 PMCID: PMC8406779 DOI: 10.1186/s12860-021-00381-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Accepted: 08/13/2021] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The 7SK small nuclear RNA (snRNA) found in most metazoans is a key regulator of P-TEFb which in turn regulates RNA polymerase II elongation. Although its primary sequence varies in protostomes, its secondary structure and function are conserved across evolutionary distant taxa. RESULTS Here, we describe a novel ncRNA sharing many features characteristic of 7SK RNAs, in D. melanogaster. We examined the structure of the corresponding gene and determined the expression profiles of the encoded RNA, called snRNA:7SK:94F, during development. It is probably produced from the transcription of a lncRNA which is processed into a mature snRNA. We also addressed its biological function and we show that, like dm7SK, this alternative 7SK interacts in vivo with the different partners of the P-TEFb complex, i.e. HEXIM, LARP7 and Cyclin T. This novel RNA is widely expressed across tissues. CONCLUSION We propose that two distinct 7SK genes might contribute to the formation of the 7SK snRNP complex in D. melanogaster.
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Affiliation(s)
- Duy Nguyen
- Université Paris-Saclay, INSERM, CNRS, Interactions cellulaires et physiopathologie hépatique, Bât.440, 91405, Orsay, France
| | | | - Olivier Fayol
- Université Paris-Saclay, INSERM, CNRS, Interactions cellulaires et physiopathologie hépatique, Bât.440, 91405, Orsay, France
| | | | - Olivier Bensaude
- IBENS Paris, UMR CNRS 8197; UA INSERM 1024, 75005, Paris, France
| | - David H Price
- Department of Biochemistry, University of Iowa, Iowa City, IA, 52242, USA
| | - Patricia Uguen
- Université Paris-Saclay, INSERM, CNRS, Interactions cellulaires et physiopathologie hépatique, Bât.440, 91405, Orsay, France.
- Present address: Université Paris-Saclay, CNRS, INSERM, Institut Curie, Intégrité du Génome, ARN et cancer, Bât. 110, 91401, Orsay cedex, France.
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Devanathan SK, Debnath TK, Xhemalçe B. Facile detection of RNA phospho-methylation in cells and tissues. Methods Enzymol 2021; 658:49-72. [PMID: 34517959 DOI: 10.1016/bs.mie.2021.06.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
RNAs from various cells and tissues are modified in nearly 200 chemically distinct ways. These modifications can be deposited either on the 5' or 3' ends, or internally on the nucleobases or sugar backbone. 5'-end modifications are crucial for protecting RNAs from untimely degradation/processing, regulating their cellular functions, or discriminating endogenous RNAs from pathogenic RNAs. 5'-end phospho-methylation is a remarkable RNA modification that is enzymatically deposited either on the γ-phosphate of nascent triphosphorylated RNAs by human BCDIN3/MePCE, or on the α-phosphate of processed monophosphorylated RNAs by human BCDIN3D. These 5'-phospho-methyltransferases are part of the BIN3 family of O-methyltransferases conserved from S. pombe to humans and play important cellular and biological roles, many of which await further elucidation. Here, we quickly recapitulate historical methods for the detection of 5'-end phospho-methyl modifications, and focus more specifically on a method that can be used to detect and quantify α-monophosphate methylation from as low as 10-100ng of total RNA from cells or tissues. This method is important for deciphering the roles of BCDIN3D and its homologs across species, as well as serves as starting point for the development of new methods for detection of 5'-end modifications.
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Affiliation(s)
- Sravan K Devanathan
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, United States
| | - Turja K Debnath
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, United States
| | - Blerta Xhemalçe
- Department of Molecular Biosciences, University of Texas at Austin, Austin, TX, United States.
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CDK9 keeps RNA polymerase II on track. Cell Mol Life Sci 2021; 78:5543-5567. [PMID: 34146121 PMCID: PMC8257543 DOI: 10.1007/s00018-021-03878-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2021] [Revised: 05/26/2021] [Accepted: 06/08/2021] [Indexed: 12/30/2022]
Abstract
Cyclin-dependent kinase 9 (CDK9), the kinase component of positive transcription elongation factor b (P-TEFb), is essential for transcription of most protein-coding genes by RNA polymerase II (RNAPII). By releasing promoter-proximally paused RNAPII into gene bodies, CDK9 controls the entry of RNAPII into productive elongation and is, therefore, critical for efficient synthesis of full-length messenger (m)RNAs. In recent years, new players involved in P-TEFb-dependent processes have been identified and an important function of CDK9 in coordinating elongation with transcription initiation and termination has been unveiled. As the regulatory functions of CDK9 in gene expression continue to expand, a number of human pathologies, including cancers, have been associated with aberrant CDK9 activity, underscoring the need to properly regulate CDK9. Here, I provide an overview of CDK9 function and regulation, with an emphasis on CDK9 dysregulation in human diseases.
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Nadeau R, Byvsheva A, Lavallée-Adam M. PIGNON: a protein-protein interaction-guided functional enrichment analysis for quantitative proteomics. BMC Bioinformatics 2021; 22:302. [PMID: 34088263 PMCID: PMC8178832 DOI: 10.1186/s12859-021-04042-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 02/22/2021] [Indexed: 12/12/2022] Open
Abstract
Background Quantitative proteomics studies are often used to detect proteins that are differentially expressed across different experimental conditions. Functional enrichment analyses are then typically used to detect annotations, such as biological processes that are significantly enriched among such differentially expressed proteins to provide insights into the molecular impacts of the studied conditions. While common, this analytical pipeline often heavily relies on arbitrary thresholds of significance. However, a functional annotation may be dysregulated in a given experimental condition, while none, or very few of its proteins may be individually considered to be significantly differentially expressed. Such an annotation would therefore be missed by standard approaches. Results Herein, we propose a novel graph theory-based method, PIGNON, for the detection of differentially expressed functional annotations in different conditions. PIGNON does not assess the statistical significance of the differential expression of individual proteins, but rather maps protein differential expression levels onto a protein–protein interaction network and measures the clustering of proteins from a given functional annotation within the network. This process allows the detection of functional annotations for which the proteins are differentially expressed and grouped in the network. A Monte-Carlo sampling approach is used to assess the clustering significance of proteins in an expression-weighted network. When applied to a quantitative proteomics analysis of different molecular subtypes of breast cancer, PIGNON detects Gene Ontology terms that are both significantly clustered in a protein–protein interaction network and differentially expressed across different breast cancer subtypes. PIGNON identified functional annotations that are dysregulated and clustered within the network between the HER2+, triple negative and hormone receptor positive subtypes. We show that PIGNON’s results are complementary to those of state-of-the-art functional enrichment analyses and that it highlights functional annotations missed by standard approaches. Furthermore, PIGNON detects functional annotations that have been previously associated with specific breast cancer subtypes. Conclusion PIGNON provides an alternative to functional enrichment analyses and a more comprehensive characterization of quantitative datasets. Hence, it contributes to yielding a better understanding of dysregulated functions and processes in biological samples under different experimental conditions. Supplementary Information The online version contains supplementary material available at 10.1186/s12859-021-04042-6.
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Affiliation(s)
- Rachel Nadeau
- Department of Biochemistry, Microbiology and Immunology, and Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Room 4170, Ottawa, ON, K1H 8M5, Canada
| | - Anastasiia Byvsheva
- Department of Biochemistry, Microbiology and Immunology, and Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Room 4170, Ottawa, ON, K1H 8M5, Canada
| | - Mathieu Lavallée-Adam
- Department of Biochemistry, Microbiology and Immunology, and Ottawa Institute of Systems Biology, Faculty of Medicine, University of Ottawa, 451 Smyth Road, Room 4170, Ottawa, ON, K1H 8M5, Canada.
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Briese M, Sendtner M. Keeping the balance: The noncoding RNA 7SK as a master regulator for neuron development and function. Bioessays 2021; 43:e2100092. [PMID: 34050960 DOI: 10.1002/bies.202100092] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2021] [Revised: 05/11/2021] [Accepted: 05/18/2021] [Indexed: 12/18/2022]
Abstract
The noncoding RNA 7SK is a critical regulator of transcription by adjusting the activity of the kinase complex P-TEFb. Release of P-TEFb from 7SK stimulates transcription at many genes by promoting productive elongation. Conversely, P-TEFb sequestration by 7SK inhibits transcription. Recent studies have shown that 7SK functions are particularly important for neuron development and maintenance and it can thus be hypothesized that 7SK is at the center of many signaling pathways contributing to neuron function. 7SK activates neuronal gene expression programs that are key for terminal differentiation of neurons. Proteomics studies revealed a complex protein interactome of 7SK that includes several RNA-binding proteins. Some of these novel 7SK subcomplexes exert non-canonical cytosolic functions in neurons by regulating axonal mRNA transport and fine-tuning spliceosome production in response to transcription alterations. Thus, a picture emerges according to which 7SK acts as a multi-functional RNA scaffold that is integral for neuron homeostasis.
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Affiliation(s)
- Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
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Fianu I, Dienemann C, Aibara S, Schilbach S, Cramer P. Cryo-EM structure of mammalian RNA polymerase II in complex with human RPAP2. Commun Biol 2021; 4:606. [PMID: 34021257 PMCID: PMC8140126 DOI: 10.1038/s42003-021-02088-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 04/08/2021] [Indexed: 11/09/2022] Open
Abstract
Nuclear import of RNA polymerase II (Pol II) involves the conserved factor RPAP2. Here we report the cryo-electron microscopy (cryo-EM) structure of mammalian Pol II in complex with human RPAP2 at 2.8 Å resolution. The structure shows that RPAP2 binds between the jaw domains of the polymerase subunits RPB1 and RPB5. RPAP2 is incompatible with binding of downstream DNA during transcription and is displaced upon formation of a transcription pre-initiation complex.
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Affiliation(s)
- Isaac Fianu
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Christian Dienemann
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Shintaro Aibara
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Sandra Schilbach
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Patrick Cramer
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany.
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Anshabo AT, Milne R, Wang S, Albrecht H. CDK9: A Comprehensive Review of Its Biology, and Its Role as a Potential Target for Anti-Cancer Agents. Front Oncol 2021; 11:678559. [PMID: 34041038 PMCID: PMC8143439 DOI: 10.3389/fonc.2021.678559] [Citation(s) in RCA: 66] [Impact Index Per Article: 22.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2021] [Accepted: 04/16/2021] [Indexed: 12/25/2022] Open
Abstract
Cyclin-dependent kinases (CDKs) are proteins pivotal to a wide range of cellular functions, most importantly cell division and transcription, and their dysregulations have been implicated as prominent drivers of tumorigenesis. Besides the well-established role of cell cycle CDKs in cancer, the involvement of transcriptional CDKs has been confirmed more recently. Most cancers overtly employ CDKs that serve as key regulators of transcription (e.g., CDK9) for a continuous production of short-lived gene products that maintain their survival. As such, dysregulation of the CDK9 pathway has been observed in various hematological and solid malignancies, making it a valuable anticancer target. This therapeutic potential has been utilized for the discovery of CDK9 inhibitors, some of which have entered human clinical trials. This review provides a comprehensive discussion on the structure and biology of CDK9, its role in solid and hematological cancers, and an updated review of the available inhibitors currently being investigated in preclinical and clinical settings.
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Affiliation(s)
- Abel Tesfaye Anshabo
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Robert Milne
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Shudong Wang
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
| | - Hugo Albrecht
- Drug Discovery and Development, Centre for Cancer Diagnostics and Therapeutics, Clinical and Health Sciences, University of South Australia, Adelaide, SA, Australia
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36
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Mandal R, Becker S, Strebhardt K. Targeting CDK9 for Anti-Cancer Therapeutics. Cancers (Basel) 2021; 13:2181. [PMID: 34062779 PMCID: PMC8124690 DOI: 10.3390/cancers13092181] [Citation(s) in RCA: 50] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 04/28/2021] [Accepted: 04/29/2021] [Indexed: 12/23/2022] Open
Abstract
Cyclin Dependent Kinase 9 (CDK9) is one of the most important transcription regulatory members of the CDK family. In conjunction with its main cyclin partner-Cyclin T1, it forms the Positive Transcription Elongation Factor b (P-TEFb) whose primary function in eukaryotic cells is to mediate the positive transcription elongation of nascent mRNA strands, by phosphorylating the S2 residues of the YSPTSPS tandem repeats at the C-terminus domain (CTD) of RNA Polymerase II (RNAP II). To aid in this process, P-TEFb also simultaneously phosphorylates and inactivates a number of negative transcription regulators like 5,6-dichloro-1-β-D-ribofuranosylbenzimidazole (DRB) Sensitivity-Inducing Factor (DSIF) and Negative Elongation Factor (NELF). Significantly enhanced activity of CDK9 is observed in multiple cancer types, which is universally associated with significantly shortened Overall Survival (OS) of the patients. In these cancer types, CDK9 regulates a plethora of cellular functions including proliferation, survival, cell cycle regulation, DNA damage repair and metastasis. Due to the extremely critical role of CDK9 in cancer cells, inhibiting its functions has been the subject of intense research, resulting the development of multiple, increasingly specific small-molecule inhibitors, some of which are presently in clinical trials. The search for newer generation CDK9 inhibitors with higher specificity and lower potential toxicities and suitable combination therapies continues. In fact, the Phase I clinical trials of the latest, highly specific CDK9 inhibitor BAY1251152, against different solid tumors have shown good anti-tumor and on-target activities and pharmacokinetics, combined with manageable safety profile while the phase I and II clinical trials of another inhibitor AT-7519 have been undertaken or are undergoing. To enhance the effectiveness and target diversity and reduce potential drug-resistance, the future of CDK9 inhibition would likely involve combining CDK9 inhibitors with inhibitors like those against BRD4, SEC, MYC, MCL-1 and HSP90.
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Affiliation(s)
- Ranadip Mandal
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Sven Becker
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
| | - Klaus Strebhardt
- Department of Gynecology and Obstetrics, Johann Wolfgang Goethe University, Theodor-Stern-Kai 7, 60590 Frankfurt am Main, Germany; (R.M.); (S.B.)
- German Cancer Consortium (DKTK), 69120 Heidelberg, Germany
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37
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Garrido-Godino AI, Gutiérrez-Santiago F, Navarro F. Biogenesis of RNA Polymerases in Yeast. Front Mol Biosci 2021; 8:669300. [PMID: 34026841 PMCID: PMC8136413 DOI: 10.3389/fmolb.2021.669300] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/31/2021] [Indexed: 01/25/2023] Open
Abstract
Eukaryotic RNA polymerases (RNA pols) transcriptional processes have been extensively investigated, and the structural analysis of eukaryotic RNA pols has been explored. However, the global assembly and biogenesis of these heteromultimeric complexes have been narrowly studied. Despite nuclear transcription being carried out by three RNA polymerases in eukaryotes (five in plants) with specificity in the synthesis of different RNA types, the biogenesis process has been proposed to be similar, at least for RNA pol II, to that of bacteria, which contains only one RNA pol. The formation of three different interacting subassembly complexes to conform the complete enzyme in the cytoplasm, prior to its nuclear import, has been assumed. In Saccharomyces cerevisiae, recent studies have examined in depth the biogenesis of RNA polymerases by characterizing some elements involved in the assembly of these multisubunit complexes, some of which are conserved in humans. This study reviews the latest studies governing the mechanisms and proteins described as being involved in the biogenesis of RNA polymerases in yeast.
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Affiliation(s)
- Ana I Garrido-Godino
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain
| | | | - Francisco Navarro
- Departamento de Biología Experimental-Genética, Universidad de Jaén, Jaén, Spain.,Centro de Estudios Avanzados en Aceite de Oliva y Olivar, Universidad de Jaén, Jaén, Spain
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38
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Cave JW, Willis DE. G-quadruplex regulation of neural gene expression. FEBS J 2021; 289:3284-3303. [PMID: 33905176 DOI: 10.1111/febs.15900] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2020] [Revised: 03/24/2021] [Accepted: 04/23/2021] [Indexed: 12/11/2022]
Abstract
G-quadruplexes are four-stranded helical nucleic acid structures characterized by stacked tetrads of guanosine bases. These structures are widespread throughout mammalian genomic DNA and RNA transcriptomes, and prevalent across all tissues. The role of G-quadruplexes in cancer is well-established, but there has been a growing exploration of these structures in the development and homeostasis of normal tissue. In this review, we focus on the roles of G-quadruplexes in directing gene expression in the nervous system, including the regulation of gene transcription, mRNA processing, and trafficking, as well as protein translation. The role of G-quadruplexes and their molecular interactions in the pathology of neurological diseases is also examined. Outside of cancer, there has been only limited exploration of G-quadruplexes as potential intervention targets to treat disease or injury. We discuss studies that have used small-molecule ligands to manipulate G-quadruplex stability in order to treat disease or direct neural stem/progenitor cell proliferation and differentiation into therapeutically relevant cell types. Understanding the many roles that G-quadruplexes have in the nervous system not only provides critical insight into fundamental molecular mechanisms that control neurological function, but also provides opportunities to identify novel therapeutic targets to treat injury and disease.
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Affiliation(s)
- John W Cave
- InVitro Cell Research LLC, Englewood, NJ, USA
| | - Dianna E Willis
- Burke Neurological Institute, White Plains, NY, USA.,Feil Family Brain & Mind Research Institute, Weill Cornell Medicine, New York, NY, USA
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39
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Cossa G, Parua PK, Eilers M, Fisher RP. Protein phosphatases in the RNAPII transcription cycle: erasers, sculptors, gatekeepers, and potential drug targets. Genes Dev 2021; 35:658-676. [PMID: 33888562 PMCID: PMC8091971 DOI: 10.1101/gad.348315.121] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
In this review, Cossa et al. discuss the current knowledge and outstanding questions about phosphatases in the context of the RNAPII transcription cycle. The transcription cycle of RNA polymerase II (RNAPII) is governed at multiple points by opposing actions of cyclin-dependent kinases (CDKs) and protein phosphatases, in a process with similarities to the cell division cycle. While important roles of the kinases have been established, phosphatases have emerged more slowly as key players in transcription, and large gaps remain in understanding of their precise functions and targets. Much of the earlier work focused on the roles and regulation of sui generis and often atypical phosphatases—FCP1, Rtr1/RPAP2, and SSU72—with seemingly dedicated functions in RNAPII transcription. Decisive roles in the transcription cycle have now been uncovered for members of the major phosphoprotein phosphatase (PPP) family, including PP1, PP2A, and PP4—abundant enzymes with pleiotropic roles in cellular signaling pathways. These phosphatases appear to act principally at the transitions between transcription cycle phases, ensuring fine control of elongation and termination. Much is still unknown, however, about the division of labor among the PPP family members, and their possible regulation by or of the transcriptional kinases. CDKs active in transcription have recently drawn attention as potential therapeutic targets in cancer and other diseases, raising the prospect that the phosphatases might also present opportunities for new drug development. Here we review the current knowledge and outstanding questions about phosphatases in the context of the RNAPII transcription cycle.
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Affiliation(s)
- Giacomo Cossa
- Department of Biochemistry and Molecular Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Pabitra K Parua
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
| | - Martin Eilers
- Department of Biochemistry and Molecular Biology, Biocenter, University of Würzburg, 97074 Würzburg, Germany
| | - Robert P Fisher
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, New York 10029, USA
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40
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The 7SK/P-TEFb snRNP controls ultraviolet radiation-induced transcriptional reprogramming. Cell Rep 2021; 35:108965. [PMID: 33852864 DOI: 10.1016/j.celrep.2021.108965] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2020] [Revised: 01/27/2021] [Accepted: 03/17/2021] [Indexed: 01/08/2023] Open
Abstract
Conversion of promoter-proximally paused RNA polymerase II (RNAPII) into elongating polymerase by the positive transcription elongation factor b (P-TEFb) is a central regulatory step of mRNA synthesis. The activity of P-TEFb is controlled mainly by the 7SK small nuclear ribonucleoprotein (snRNP), which sequesters active P-TEFb into inactive 7SK/P-TEFb snRNP. Here we demonstrate that under normal culture conditions, the lack of 7SK snRNP has only minor impacts on global RNAPII transcription without detectable consequences on cell proliferation. However, upon ultraviolet (UV)-light-induced DNA damage, cells lacking 7SK have a defective transcriptional response and reduced viability. Both UV-induced release of "lesion-scanning" polymerases and activation of key early-responsive genes are compromised in the absence of 7SK. Proper induction of 7SK-dependent UV-responsive genes requires P-TEFb activity directly mobilized from the nucleoplasmic 7SK/P-TEFb snRNP. Our data demonstrate that the primary function of the 7SK/P-TEFb snRNP is to orchestrate the proper transcriptional response to stress.
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41
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Chen L, Zhao M, Wu Z, Chen S, Rojo E, Luo J, Li P, Zhao L, Chen Y, Deng J, Cheng B, He K, Gou X, Li J, Hou S. RNA polymerase II associated proteins regulate stomatal development through direct interaction with stomatal transcription factors in Arabidopsis thaliana. THE NEW PHYTOLOGIST 2021; 230:171-189. [PMID: 33058210 DOI: 10.1111/nph.17004] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2020] [Accepted: 10/05/2020] [Indexed: 05/27/2023]
Abstract
RNA polymerase II (Pol II) associated proteins (RPAPs) have been ascribed diverse functions at the cellular level; however, their roles in developmental processes in yeasts, animals and plants are very poorly understood. Through screening for interactors of NRPB3, which encodes the third largest subunit of Pol II, we identified RIMA, the orthologue of mammalian RPAP2. A combination of genetic and biochemical assays revealed the role of RIMA and other RPAPs in stomatal development in Arabidopsis thaliana. We show that RIMA is involved in nuclear import of NRPB3 and other Pol II subunits, and is essential for restraining division and for establishing cell identity in the stomatal cell lineage. Moreover, plant RPAPs IYO/RPAP1 and QQT1/RPAP4, which interact with RIMA, are also crucial for stomatal development. Importantly, RIMA and QQT1 bind physically to stomatal transcription factors SPEECHLESS, MUTE, FAMA and SCREAMs. The RIMA-QQT1-IYO complex could work together with key stomatal transcription factors and Pol II to drive cell fate transitions in the stomatal cell lineage. Direct interactions with stomatal transcription factors provide a novel mechanism by which RPAP proteins may control differentiation of cell types and tissues in eukaryotes.
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Affiliation(s)
- Liang Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Mingfeng Zhao
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Zhongliang Wu
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Sicheng Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Enrique Rojo
- Centro Nacional de Biotecnología-CSIC, Cantoblanco, Madrid, E-28049, Spain
| | - Jiangwei Luo
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Ping Li
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Lulu Zhao
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Yan Chen
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jianming Deng
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Bo Cheng
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Kai He
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Xiaoping Gou
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Jia Li
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
| | - Suiwen Hou
- Key Laboratory of Cell Activities and Stress Adaptations, Ministry of Education, School of Life Sciences, Lanzhou University, Lanzhou, 730000, China
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42
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Ji C, Bader J, Ramanathan P, Hennlein L, Meissner F, Jablonka S, Mann M, Fischer U, Sendtner M, Briese M. Interaction of 7SK with the Smn complex modulates snRNP production. Nat Commun 2021; 12:1278. [PMID: 33627647 PMCID: PMC7904863 DOI: 10.1038/s41467-021-21529-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/29/2021] [Indexed: 11/09/2022] Open
Abstract
Gene expression requires tight coordination of the molecular machineries that mediate transcription and splicing. While the interplay between transcription kinetics and spliceosome fidelity has been investigated before, less is known about mechanisms regulating the assembly of the spliceosomal machinery in response to transcription changes. Here, we report an association of the Smn complex, which mediates spliceosomal snRNP biogenesis, with the 7SK complex involved in transcriptional regulation. We found that Smn interacts with the 7SK core components Larp7 and Mepce and specifically associates with 7SK subcomplexes containing hnRNP R. The association between Smn and 7SK complexes is enhanced upon transcriptional inhibition leading to reduced production of snRNPs. Taken together, our findings reveal a functional association of Smn and 7SK complexes that is governed by global changes in transcription. Thus, in addition to its canonical nuclear role in transcriptional regulation, 7SK has cytosolic functions in fine-tuning spliceosome production according to transcriptional demand. The noncoding RNA 7SK controls the transcription of mRNAs. Here, the authors show that the 7SK complex interacts with the Smn complex, suggesting crosstalk between transcription and snRNP assembly.
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Affiliation(s)
- Changhe Ji
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Jakob Bader
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Pradhipa Ramanathan
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Felix Meissner
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany.,Experimental Systems Immunology, Max Planck Institute of Biochemistry, Martinsried, Germany.,Department for Systems Immunology & Proteomics, Institute of Innate Immunity, University Hospitals, University of Bonn, Bonn, Germany
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany
| | - Matthias Mann
- Department of Proteomics and Signal Transduction, Max Planck Institute of Biochemistry, Martinsried, Germany.,NNF Center for Protein Research, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Utz Fischer
- Department of Biochemistry, Theodor Boveri Institute, University of Wuerzburg, Wuerzburg, Germany
| | - Michael Sendtner
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Wuerzburg, Wuerzburg, Germany.
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43
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Ruszkowska A. METTL16, Methyltransferase-Like Protein 16: Current Insights into Structure and Function. Int J Mol Sci 2021; 22:ijms22042176. [PMID: 33671635 PMCID: PMC7927073 DOI: 10.3390/ijms22042176] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 02/03/2021] [Accepted: 02/16/2021] [Indexed: 12/31/2022] Open
Abstract
Methyltransferase-like protein 16 (METTL16) is a human RNA methyltransferase that installs m6A marks on U6 small nuclear RNA (U6 snRNA) and S-adenosylmethionine (SAM) synthetase pre-mRNA. METTL16 also controls a significant portion of m6A epitranscriptome by regulating SAM homeostasis. Multiple molecular structures of the N-terminal methyltransferase domain of METTL16, including apo forms and complexes with S-adenosylhomocysteine (SAH) or RNA, provided the structural basis of METTL16 interaction with the coenzyme and substrates, as well as indicated autoinhibitory mechanism of the enzyme activity regulation. Very recent structural and functional studies of vertebrate-conserved regions (VCRs) indicated their crucial role in the interaction with U6 snRNA. METTL16 remains an object of intense studies, as it has been associated with numerous RNA classes, including mRNA, non-coding RNA, long non-coding RNA (lncRNA), and rRNA. Moreover, the interaction between METTL16 and oncogenic lncRNA MALAT1 indicates the existence of METTL16 features specifically recognizing RNA triple helices. Overall, the number of known human m6A methyltransferases has grown from one to five during the last five years. METTL16, CAPAM, and two rRNA methyltransferases, METTL5/TRMT112 and ZCCHC4, have joined the well-known METTL3/METTL14. This work summarizes current knowledge about METTL16 in the landscape of human m6A RNA methyltransferases.
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Affiliation(s)
- Agnieszka Ruszkowska
- Department of Structural Chemistry and Biology of Nucleic Acids, Institute of Bioorganic Chemistry, Polish Academy of Sciences, 61-704 Poznan, Poland
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44
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Depicting HIV-1 Transcriptional Mechanisms: A Summary of What We Know. Viruses 2020; 12:v12121385. [PMID: 33287435 PMCID: PMC7761857 DOI: 10.3390/v12121385] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Revised: 11/26/2020] [Accepted: 12/01/2020] [Indexed: 12/19/2022] Open
Abstract
Despite the introduction of combinatory antiretroviral therapy (cART), HIV-1 infection cannot be cured and is still one of the major health issues worldwide. Indeed, as soon as cART is interrupted, a rapid rebound of viremia is observed. The establishment of viral latency and the persistence of the virus in cellular reservoirs constitute the main barrier to HIV eradication. For this reason, new therapeutic approaches have emerged to purge or restrain the HIV-1 reservoirs in order to cure infected patients. However, the viral latency is a multifactorial process that depends on various cellular mechanisms. Since these new therapies mainly target viral transcription, their development requires a detailed and precise understanding of the regulatory mechanism underlying HIV-1 transcription. In this review, we discuss the complex molecular transcriptional network regulating HIV-1 gene expression by focusing on the involvement of host cell factors that could be used as potential drug targets to design new therapeutic strategies and, to a larger extent, to reach an HIV-1 functional cure.
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45
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Vandelli A, Monti M, Milanetti E, Armaos A, Rupert J, Zacco E, Bechara E, Delli Ponti R, Tartaglia GG. Structural analysis of SARS-CoV-2 genome and predictions of the human interactome. Nucleic Acids Res 2020. [PMID: 33068416 DOI: 10.1101/2020.03.28.013789] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/07/2023] Open
Abstract
Specific elements of viral genomes regulate interactions within host cells. Here, we calculated the secondary structure content of >2000 coronaviruses and computed >100 000 human protein interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The genomic regions display different degrees of conservation. SARS-CoV-2 domain encompassing nucleotides 22 500-23 000 is conserved both at the sequence and structural level. The regions upstream and downstream, however, vary significantly. This part of the viral sequence codes for the Spike S protein that interacts with the human receptor angiotensin-converting enzyme 2 (ACE2). Thus, variability of Spike S is connected to different levels of viral entry in human cells within the population. Our predictions indicate that the 5' end of SARS-CoV-2 is highly structured and interacts with several human proteins. The binding proteins are involved in viral RNA processing, include double-stranded RNA specific editases and ATP-dependent RNA-helicases and have strong propensity to form stress granules and phase-separated assemblies. We propose that these proteins, also implicated in viral infections such as HIV, are selectively recruited by SARS-CoV-2 genome to alter transcriptional and post-transcriptional regulation of host cells and to promote viral replication.
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Affiliation(s)
- Andrea Vandelli
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Systems Biology of Infection Lab, Department of Biochemistry and Molecular Biology, Biosciences Faculty, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - Michele Monti
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Edoardo Milanetti
- Department of Physics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Center for Life Nanoscience, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Alexandros Armaos
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Jakob Rupert
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
- Department of Biology 'Charles Darwin', Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Elsa Zacco
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Elias Bechara
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Riccardo Delli Ponti
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
- Department of Biology 'Charles Darwin', Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
- Institucio Catalana de Recerca i Estudis Avançats (ICREA), 23 Passeig Lluis Companys, 08010 Barcelona, Spain
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46
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Vandelli A, Monti M, Milanetti E, Armaos A, Rupert J, Zacco E, Bechara E, Delli Ponti R, Tartaglia G. Structural analysis of SARS-CoV-2 genome and predictions of the human interactome. Nucleic Acids Res 2020; 48:11270-11283. [PMID: 33068416 PMCID: PMC7672441 DOI: 10.1093/nar/gkaa864] [Citation(s) in RCA: 65] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 09/15/2020] [Accepted: 09/25/2020] [Indexed: 12/17/2022] Open
Abstract
Specific elements of viral genomes regulate interactions within host cells. Here, we calculated the secondary structure content of >2000 coronaviruses and computed >100 000 human protein interactions with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The genomic regions display different degrees of conservation. SARS-CoV-2 domain encompassing nucleotides 22 500-23 000 is conserved both at the sequence and structural level. The regions upstream and downstream, however, vary significantly. This part of the viral sequence codes for the Spike S protein that interacts with the human receptor angiotensin-converting enzyme 2 (ACE2). Thus, variability of Spike S is connected to different levels of viral entry in human cells within the population. Our predictions indicate that the 5' end of SARS-CoV-2 is highly structured and interacts with several human proteins. The binding proteins are involved in viral RNA processing, include double-stranded RNA specific editases and ATP-dependent RNA-helicases and have strong propensity to form stress granules and phase-separated assemblies. We propose that these proteins, also implicated in viral infections such as HIV, are selectively recruited by SARS-CoV-2 genome to alter transcriptional and post-transcriptional regulation of host cells and to promote viral replication.
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Affiliation(s)
- Andrea Vandelli
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Systems Biology of Infection Lab, Department of Biochemistry and Molecular Biology, Biosciences Faculty, Universitat Autònoma de Barcelona, 08193 Cerdanyola del Vallès, Spain
| | - Michele Monti
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Edoardo Milanetti
- Department of Physics, Sapienza University, Piazzale Aldo Moro 5, 00185 Rome, Italy
- Center for Life Nanoscience, Istituto Italiano di Tecnologia, Viale Regina Elena 291, 00161 Rome, Italy
| | - Alexandros Armaos
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Jakob Rupert
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
- Department of Biology ‘Charles Darwin’, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
| | - Elsa Zacco
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Elias Bechara
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
| | - Riccardo Delli Ponti
- School of Biological Sciences, Nanyang Technological University, 60 Nanyang Drive, Singapore 637551, Singapore
| | - Gian Gaetano Tartaglia
- Centre for Genomic Regulation (CRG), The Barcelona Institute for Science and Technology, Dr. Aiguader 88, 08003 Barcelona, Spain and Universitat Pompeu Fabra (UPF), 08003 Barcelona, Spain
- Center for Human Technologies, Istituto Italiano di Tecnologia, Via Enrico Melen 83, 16152 Genoa, Italy
- Department of Biology ‘Charles Darwin’, Sapienza University of Rome, P.le A. Moro 5, Rome 00185, Italy
- Institucio Catalana de Recerca i Estudis Avançats (ICREA), 23 Passeig Lluis Companys, 08010 Barcelona, Spain
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Brunet M, Vargas C, Larrieu D, Torrisani J, Dufresne M. E3 Ubiquitin Ligase TRIP12: Regulation, Structure, and Physiopathological Functions. Int J Mol Sci 2020; 21:ijms21228515. [PMID: 33198194 PMCID: PMC7697007 DOI: 10.3390/ijms21228515] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 11/04/2020] [Accepted: 11/05/2020] [Indexed: 02/06/2023] Open
Abstract
The Thyroid hormone Receptor Interacting Protein 12 (TRIP12) protein belongs to the 28-member Homologous to the E6-AP C-Terminus (HECT) E3 ubiquitin ligase family. First described as an interactor of the thyroid hormone receptor, TRIP12’s biological importance was revealed by the embryonic lethality of a murine model bearing an inactivating mutation in the TRIP12 gene. Further studies showed the participation of TRIP12 in the regulation of major biological processes such as cell cycle progression, DNA damage repair, chromatin remodeling, and cell differentiation by an ubiquitination-mediated degradation of key protein substrates. Moreover, alterations of TRIP12 expression have been reported in cancers that can serve as predictive markers of therapeutic response. The TRIP12 gene is also referenced as a causative gene associated to intellectual disorders such as Clark–Baraitser syndrome and is clearly implicated in Autism Spectrum Disorder. The aim of the review is to provide an exhaustive and integrated overview of the different aspects of TRIP12 ranging from its regulation, molecular functions and physio-pathological implications.
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Affiliation(s)
- Manon Brunet
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Claire Vargas
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Dorian Larrieu
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
| | - Jérôme Torrisani
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
- Correspondence: (J.T.); (M.D.); Tel.: +33-582-741-644 (J.T.); +33-582-741-643 (M.D.)
| | - Marlène Dufresne
- Institut National de la Santé et de la Recherche Médicale, INSERM Unit 1037, Centre de Recherches en Cancérologie de Toulouse, CEDEX 1, 31 037 Toulouse, France; (M.B.); (C.V.); (D.L.)
- Université Toulouse III-Paul Sabatier, CEDEX 9, 31 062 Toulouse, France
- Correspondence: (J.T.); (M.D.); Tel.: +33-582-741-644 (J.T.); +33-582-741-643 (M.D.)
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Pedley R, King LE, Mallikarjun V, Wang P, Swift J, Brennan K, Gilmore AP. BioID-based proteomic analysis of the Bid interactome identifies novel proteins involved in cell-cycle-dependent apoptotic priming. Cell Death Dis 2020; 11:872. [PMID: 33067418 PMCID: PMC7567853 DOI: 10.1038/s41419-020-03091-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Revised: 09/24/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022]
Abstract
Apoptotic priming controls the commitment of cells to apoptosis by determining how close they lie to mitochondrial permeabilisation. Variations in priming are important for how both healthy and cancer cells respond to chemotherapeutic agents, but how it is dynamically coordinated by Bcl-2 proteins remains unclear. The Bcl-2 family protein Bid is phosphorylated when cells enter mitosis, increasing apoptotic priming and sensitivity to antimitotic drugs. Here, we report an unbiased proximity biotinylation (BioID) screen to identify regulators of apoptotic priming in mitosis, using Bid as bait. The screen primarily identified proteins outside of the canonical Bid interactome. Specifically, we found that voltage-dependent anion-selective channel protein 2 (VDAC2) was required for Bid phosphorylation-dependent changes in apoptotic priming during mitosis. These results highlight the importance of the wider Bcl-2 family interactome in regulating the temporal control of apoptotic priming.
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Affiliation(s)
- Robert Pedley
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Louise E King
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Venkatesh Mallikarjun
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Pengbo Wang
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Cancer Research UK Manchester Institute, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Joe Swift
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
- Division of Cell Matrix Biology and Regenerative Medicine, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Keith Brennan
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK
| | - Andrew P Gilmore
- Wellcome Centre for Cell-Matrix Research, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
- Division of Cancer Sciences, Faculty of Biology, Medicine and Health, Manchester Academic Health Science Centre, University of Manchester, Manchester, UK.
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Brillet K, Martinez-Zapien D, Bec G, Ennifar E, Dock-Bregeon AC, Lebars I. Different views of the dynamic landscape covered by the 5'-hairpin of the 7SK small nuclear RNA. RNA (NEW YORK, N.Y.) 2020; 26:1184-1197. [PMID: 32430362 PMCID: PMC7430674 DOI: 10.1261/rna.074955.120] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 05/13/2020] [Indexed: 06/11/2023]
Abstract
The 7SK small nuclear RNA (7SKsnRNA) plays a key role in the regulation of RNA polymerase II by sequestrating and inhibiting the positive transcription elongation factor b (P-TEFb) in the 7SK ribonucleoprotein complex (7SKsnRNP), a process mediated by interaction with the protein HEXIM. P-TEFb is also an essential cellular factor recruited by the viral protein Tat to ensure the replication of the viral RNA in the infection cycle of the human immunodeficiency virus (HIV-1). Tat promotes the release of P-TEFb from the 7SKsnRNP and subsequent activation of transcription, by displacing HEXIM from the 5'-hairpin of the 7SKsnRNA. This hairpin (HP1), comprising the signature sequence of the 7SKsnRNA, has been the subject of three independent structural studies aimed at identifying the structural features that could drive the recognition by the two proteins, both depending on arginine-rich motifs (ARM). Interestingly, four distinct structures were determined. In an attempt to provide a comprehensive view of the structure-function relationship of this versatile RNA, we present here a structural analysis of the models, highlighting how HP1 is able to adopt distinct conformations with significant impact on the compactness of the molecule. Since these models are solved under different conditions by nuclear magnetic resonance (NMR) and crystallography, the impact of the buffer composition on the conformational variation was investigated by complementary biophysical approaches. Finally, using isothermal titration calorimetry, we determined the thermodynamic signatures of the Tat-ARM and HEXIM-ARM peptide interactions with the RNA, showing that they are associated with distinct binding mechanisms.
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Affiliation(s)
- Karl Brillet
- Université de Strasbourg, Architecture et Réactivité de l'ARN - CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, F-67084 Strasbourg, France
| | - Denise Martinez-Zapien
- Department of Integrated Structural Biology, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), CNRS UMR 7104, INSERM U964, Université de Strasbourg, 67404 Illkirch Cedex, France
| | - Guillaume Bec
- Université de Strasbourg, Architecture et Réactivité de l'ARN - CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, F-67084 Strasbourg, France
| | - Eric Ennifar
- Université de Strasbourg, Architecture et Réactivité de l'ARN - CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, F-67084 Strasbourg, France
| | - Anne-Catherine Dock-Bregeon
- Laboratory of Integrative Biology of Marine Models (LBI2M), Sorbonne University-CNRS UMR 8227, Station Biologique de Roscoff, 29680 Roscoff Cedex, France
| | - Isabelle Lebars
- Université de Strasbourg, Architecture et Réactivité de l'ARN - CNRS UPR 9002, Institut de Biologie Moléculaire et Cellulaire, F-67084 Strasbourg, France
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50
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Shao H, Zhu Q, Lu H, Chang A, Gao C, Zhou Q, Luo K. HEXIM1 controls P-TEFb processing and regulates drug sensitivity in triple-negative breast cancer. Mol Biol Cell 2020; 31:1867-1878. [PMID: 32520633 PMCID: PMC7525814 DOI: 10.1091/mbc.e19-12-0704] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 05/28/2020] [Accepted: 06/02/2020] [Indexed: 11/16/2022] Open
Abstract
The positive transcription elongation factor b (P-TEFb), composed of CDK9 and cyclin T, stimulates transcriptional elongation by RNA polymerase (Pol) II and regulates cell growth and differentiation. Recently, we demonstrated that P-TEFb also controls the expression of EMT regulators to promote breast cancer progression. In the nucleus, more than half of P-TEFb are sequestered in the inactive-state 7SK snRNP complex. Here, we show that the assembly of the 7SK snRNP is preceded by an intermediate complex between HEXIM1 and P-TEFb that allows transfer of the kinase active P-TEFb from Hsp90 to 7SK snRNP for its suppression. Down-regulation of HEXIM1 locks P-TEFb in the Hsp90 complex, keeping it in the active state to enhance breast cancer progression, but also rendering the cells highly sensitive to Hsp90 inhibition. Because HEXIM1 is often down-regulated in human triple-negative breast cancer (TNBC), these cells are particularly sensitive to Hsp90 inhibition. Our study provides a mechanistic explanation for the increased sensitivity of TNBC to Hsp90 inhibition.
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Affiliation(s)
- Hengyi Shao
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Qingwei Zhu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Huasong Lu
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Amanda Chang
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Carol Gao
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Qiang Zhou
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
| | - Kunxin Luo
- Department of Molecular and Cell Biology, University of California, Berkeley, CA 94720
- Life Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720
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