1
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Sedor SF, Shao S. Mechanism of ASF1 Inhibition by CDAN1. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.08.08.607204. [PMID: 39149339 PMCID: PMC11326237 DOI: 10.1101/2024.08.08.607204] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/17/2024]
Abstract
Codanin-1 (CDAN1) is an essential and ubiquitous protein named after congenital dyserythropoietic anemia type I (CDA-I), an autosomal recessive disease that manifests from mutations in the CDAN1 or CDIN1 (CDAN1 interacting nuclease 1) gene. CDAN1 interacts with CDIN1 and the paralogous histone H3-H4 chaperones ASF1A (Anti-Silencing Function 1A) and ASF1B, but its function remains unclear. Here, we biochemically and structurally analyze CDAN1 complexes. We find that CDAN1 dimerizes and assembles into cytosolic complexes with CDIN1 and multiple copies of ASF1A/B. Single-particle cryogenic electron microscopy (cryo-EM) structures of CDAN1 complexes identify interactions with ASF1 mediated by two CDAN1 B-domains commonly found in ASF1 binding partners and two helices that mimic histone H3 binding. We additionally observe that one CDAN1 can recruit two ASF1 molecules and that ASF1A and ASF1B have different requirements for CDAN1 engagement. Our findings explain how CDAN1 sequesters and inhibits the chaperone function of ASF1A/B and provide new molecular-level insights into this enigmatic complex.
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Affiliation(s)
- Samantha F Sedor
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
| | - Sichen Shao
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115
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2
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Yellamaty R, Sharma S. Critical Cellular Functions and Mechanisms of Action of the RNA Helicase UAP56. J Mol Biol 2024; 436:168604. [PMID: 38729260 PMCID: PMC11168752 DOI: 10.1016/j.jmb.2024.168604] [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: 03/06/2024] [Revised: 04/24/2024] [Accepted: 05/03/2024] [Indexed: 05/12/2024]
Abstract
Posttranscriptional maturation and export from the nucleus to the cytoplasm are essential steps in the normal processing of many cellular RNAs. The RNA helicase UAP56 (U2AF associated protein 56; also known as DDX39B) has emerged as a critical player in facilitating and co-transcriptionally linking these steps. Originally identified as a helicase involved in pre-mRNA splicing, UAP56 has been shown to facilitate formation of the A complex during spliceosome assembly. Additionally, it has been found to be critical for interactions between components of the exon junction and transcription and export complexes to promote the loading of export receptors. Although it appears to be structurally similar to other helicase superfamily 2 members, UAP56's ability to interact with multiple different protein partners allows it to perform its various cellular functions. Herein, we describe the structure-activity relationship studies that identified protein interactions of UAP56 and its human paralog URH49 (UAP56-related helicase 49; also known as DDX39A) and are beginning to reveal molecular mechanisms by which interacting proteins and substrate RNAs may regulate these helicases. We also provide an overview of reports that have demonstrated less well-characterized roles for UAP56, including R-loop resolution and telomere maintenance. Finally, we discuss studies that indicate a potential pathogenic effect of UAP56 in the development of autoimmune diseases and cancer, and identify the association of somatic and genetic mutations in UAP56 with neurodevelopmental disorders.
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Affiliation(s)
- Ryan Yellamaty
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ 85004, USA
| | - Shalini Sharma
- Department of Basic Medical Sciences, College of Medicine-Phoenix, University of Arizona, Phoenix, AZ 85004, USA.
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3
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Pfannenstein J, Tyryshkin M, Gulden ME, Doud EH, Mosley AL, Reese JC. Characterization of BioID tagging systems in budding yeast and exploring the interactome of the Ccr4-Not complex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.09.593354. [PMID: 38766143 PMCID: PMC11100836 DOI: 10.1101/2024.05.09.593354] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2024]
Abstract
The modified E. coli biotin ligase BirA* was the first developed for proximity labeling of proteins (BioID). However, it has low activity at temperatures below 37°C, which reduces its effectiveness in organisms growing at lower temperatures, such as budding yeast. Multiple derivatives of the enzymes have been engineered, but a comparison of these variations of biotin ligases has not been reported in Saccharomyces cerevisiae. Here, we designed a suite of vectors to compare the activities of biotin ligase enzymes in yeast. We found that the newer TurboID versions were the most effective at labeling proteins, but they displayed low constitutive activity from biotin contained in the culture medium. We describe a simple strategy to express free BioID enzymes in cells that can be used as an appropriate control in BioID studies to account for the promiscuous labeling of proteins caused by random interactions between bait-BioID enzymes in cells. We also describe chemically-induced BioID systems exploiting the rapamycin-stabilized FRB-FKBP interaction. Finally, we used the TurboID version of the enzyme to explore the interactome of different subunits of the Ccr4-Not gene regulatory complex. We find that Ccr4-Not predominantly labeled cytoplasmic mRNA regulators, consistent with its function in mRNA decay and translation quality control in this cell compartment.
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4
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Collart MA, Audebert L, Bushell M. Roles of the CCR4-Not complex in translation and dynamics of co-translation events. WILEY INTERDISCIPLINARY REVIEWS. RNA 2023; 15:e1827. [PMID: 38009591 PMCID: PMC10909573 DOI: 10.1002/wrna.1827] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 10/06/2023] [Accepted: 10/30/2023] [Indexed: 11/29/2023]
Abstract
The Ccr4-Not complex is a global regulator of mRNA metabolism in eukaryotic cells that is most well-known to repress gene expression. Delivery of the complex to mRNAs through a multitude of distinct mechanisms accelerates their decay, yet Ccr4-Not also plays an important role in co-translational processes, such as co-translational association of proteins and delivery of translating mRNAs to organelles. The recent structure of Not5 interacting with the translated ribosome has brought to light that embedded information within the codon sequence can be monitored by recruitment of the Ccr4-Not complex to elongating ribosomes. Thereby, the Ccr4-Not complex is empowered with regulatory decisions determining the fate of proteins being synthesized and their encoding mRNAs. This review will focus on the roles of the complex in translation and dynamics of co-translation events. This article is categorized under: Translation > Mechanisms Translation > Regulation.
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Affiliation(s)
- Martine A. Collart
- Department of Microbiology and Molecular MedicineInstitute of Genetics and Genomics Geneva, University of Geneva, Faculty of MedicineGenèveSwitzerland
| | - Léna Audebert
- Department of Microbiology and Molecular MedicineInstitute of Genetics and Genomics Geneva, University of Geneva, Faculty of MedicineGenèveSwitzerland
| | - Martin Bushell
- Cancer Research UK Beatson InstituteGlasgowUK
- School of Cancer Sciences, University of GlasgowGlasgowUK
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5
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Krempl C, Lazzaretti D, Sprangers R. A structural biology view on the enzymes involved in eukaryotic mRNA turnover. Biol Chem 2023; 404:1101-1121. [PMID: 37709756 DOI: 10.1515/hsz-2023-0182] [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: 04/13/2023] [Accepted: 08/24/2023] [Indexed: 09/16/2023]
Abstract
The cellular environment contains numerous ribonucleases that are dedicated to process mRNA transcripts that have been targeted for degradation. Here, we review the three dimensional structures of the ribonuclease complexes (Pan2-Pan3, Ccr4-Not, Xrn1, exosome) and the mRNA decapping enzymes (Dcp2, DcpS) that are involved in mRNA turnover. Structures of major parts of these proteins have been experimentally determined. These enzymes and factors do not act in isolation, but are embedded in interaction networks which regulate enzyme activity and ensure that the appropriate substrates are recruited. The structural details of the higher order complexes that form can, in part, be accurately deduced from known structural data of sub-complexes. Interestingly, many of the ribonuclease and decapping enzymes have been observed in structurally different conformations. Together with experimental data, this highlights that structural changes are often important for enzyme function. We conclude that the known structural data of mRNA decay factors provide important functional insights, but that static structural data needs to be complemented with information regarding protein motions to complete the picture of how transcripts are turned over. In addition, we highlight multiple aspects that influence mRNA turnover rates, but that have not been structurally characterized so far.
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Affiliation(s)
- Christina Krempl
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Daniela Lazzaretti
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
| | - Remco Sprangers
- Institute of Biophysics and Physical Biochemistry, Regensburg Center for Biochemistry, University of Regensburg, D-93053 Regensburg, Germany
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6
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Zhao Q, Pavanello L, Bartlam M, Winkler GS. Structure and function of molecular machines involved in deadenylation-dependent 5'-3' mRNA degradation. Front Genet 2023; 14:1233842. [PMID: 37876592 PMCID: PMC10590902 DOI: 10.3389/fgene.2023.1233842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2023] [Accepted: 09/25/2023] [Indexed: 10/26/2023] Open
Abstract
In eukaryotic cells, the synthesis, processing, and degradation of mRNA are important processes required for the accurate execution of gene expression programmes. Fully processed cytoplasmic mRNA is characterised by the presence of a 5'cap structure and 3'poly(A) tail. These elements promote translation and prevent non-specific degradation. Degradation via the deadenylation-dependent 5'-3' degradation pathway can be induced by trans-acting factors binding the mRNA, such as RNA-binding proteins recognising sequence elements and the miRNA-induced repression complex. These factors recruit the core mRNA degradation machinery that carries out the following steps: i) shortening of the poly(A) tail by the Ccr4-Not and Pan2-Pan3 poly (A)-specific nucleases (deadenylases); ii) removal of the 5'cap structure by the Dcp1-Dcp2 decapping complex that is recruited by the Lsm1-7-Pat1 complex; and iii) degradation of the mRNA body by the 5'-3' exoribonuclease Xrn1. In this review, the biochemical function of the nucleases and accessory proteins involved in deadenylation-dependent mRNA degradation will be reviewed with a particular focus on structural aspects of the proteins and enzymes involved.
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Affiliation(s)
- Qi Zhao
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai International Advanced Research Institute (Shenzhen Futian), Nankai University, Tianjin, China
| | - Lorenzo Pavanello
- School of Pharmacy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Mark Bartlam
- State Key Laboratory of Medicinal Chemical Biology, College of Life Sciences, Nankai International Advanced Research Institute (Shenzhen Futian), Nankai University, Tianjin, China
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7
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Bohnsack KE, Yi S, Venus S, Jankowsky E, Bohnsack MT. Cellular functions of eukaryotic RNA helicases and their links to human diseases. Nat Rev Mol Cell Biol 2023; 24:749-769. [PMID: 37474727 DOI: 10.1038/s41580-023-00628-5] [Citation(s) in RCA: 41] [Impact Index Per Article: 41.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/13/2023] [Indexed: 07/22/2023]
Abstract
RNA helicases are highly conserved proteins that use nucleoside triphosphates to bind or remodel RNA, RNA-protein complexes or both. RNA helicases are classified into the DEAD-box, DEAH/RHA, Ski2-like, Upf1-like and RIG-I families, and are the largest class of enzymes active in eukaryotic RNA metabolism - virtually all aspects of gene expression and its regulation involve RNA helicases. Mutation and dysregulation of these enzymes have been linked to a multitude of diseases, including cancer and neurological disorders. In this Review, we discuss the regulation and functional mechanisms of RNA helicases and their roles in eukaryotic RNA metabolism, including in transcription regulation, pre-mRNA splicing, ribosome assembly, translation and RNA decay. We highlight intriguing models that link helicase structure, mechanisms of function (such as local strand unwinding, translocation, winching, RNA clamping and displacing RNA-binding proteins) and biological roles, including emerging connections between RNA helicases and cellular condensates formed through liquid-liquid phase separation. We also discuss associations of RNA helicases with human diseases and recent efforts towards the design of small-molecule inhibitors of these pivotal regulators of eukaryotic gene expression.
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Affiliation(s)
- Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
| | - Soon Yi
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Sarah Venus
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
- Moderna, Cambridge, MA, USA.
| | - Markus T Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany.
- Göttingen Centre for Molecular Biosciences, University of Göttingen, Göttingen, Germany.
- Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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8
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Pavanello L, Hall M, Winkler GS. Regulation of eukaryotic mRNA deadenylation and degradation by the Ccr4-Not complex. Front Cell Dev Biol 2023; 11:1153624. [PMID: 37152278 PMCID: PMC10157403 DOI: 10.3389/fcell.2023.1153624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2023] [Accepted: 03/20/2023] [Indexed: 05/09/2023] Open
Abstract
Accurate and precise regulation of gene expression programmes in eukaryotes involves the coordinated control of transcription, mRNA stability and translation. In recent years, significant progress has been made about the role of sequence elements in the 3' untranslated region for the regulation of mRNA degradation, and a model has emerged in which recruitment of the Ccr4-Not complex is the critical step in the regulation of mRNA decay. Recruitment of the Ccr4-Not complex to a target mRNA results in deadenylation mediated by the Caf1 and Ccr4 catalytic subunits of the complex. Following deadenylation, the 5' cap structure is removed, and the mRNA subjected to 5'-3' degradation. Here, the role of the human Ccr4-Not complex in cytoplasmic deadenylation of mRNA is reviewed, with a particular focus on mechanisms of its recruitment to mRNA by sequence motifs in the 3' untranslated region, codon usage, as well as general mechanisms involving the poly(A) tail.
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Affiliation(s)
- Lorenzo Pavanello
- School of Pharmacy, University of Nottingham, University Park, Nottingham, United Kingdom
| | - Michael Hall
- School of Pharmacy, University of Nottingham, University Park, Nottingham, United Kingdom
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9
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Raisch T, Valkov E. Regulation of the multisubunit CCR4-NOT deadenylase in the initiation of mRNA degradation. Curr Opin Struct Biol 2022; 77:102460. [PMID: 36116370 PMCID: PMC9771892 DOI: 10.1016/j.sbi.2022.102460] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Revised: 07/19/2022] [Accepted: 08/10/2022] [Indexed: 12/24/2022]
Abstract
The conserved CCR4-NOT complex initiates the decay of mRNAs by catalyzing the shortening of their poly(A) tails in a process known as deadenylation. Recent studies have provided mechanistic insights into the action and regulation of this molecular machine. The two catalytic enzymatic subunits of the complex hydrolyze polyadenosine RNA. Notably, the non-catalytic subunits substantially enhance the complex's affinity and sequence selectivity for polyadenosine by directly contacting the RNA. An additional regulatory mechanism is the active recruitment of the CCR4-NOT to transcripts targeted for decay by RNA-binding proteins that recognize motifs or sequences residing predominantly in untranslated regions. This targeting and strict control of the mRNA deadenylation process emerges as a crucial nexus during post-transcriptional regulation of gene expression.
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Affiliation(s)
- Tobias Raisch
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Otto-Hahn-Strasse 11, 44227 Dortmund, Germany.
| | - Eugene Valkov
- RNA Biology Laboratory & Center for Structural Biology, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702-1201, USA.
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10
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Rambout X, Maquat LE. The nuclear cap-binding complex as choreographer of gene transcription and pre-mRNA processing. Genes Dev 2021; 34:1113-1127. [PMID: 32873578 PMCID: PMC7462061 DOI: 10.1101/gad.339986.120] [Citation(s) in RCA: 38] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
In this review, Rambout and Maquat discuss known roles of the nuclear cap-binding complex (CBC) during the transcription of genes that encode proteins, stitching together past studies from diverse groups to describe the continuum of CBC-mediated checks and balances in eukaryotic cells. The largely nuclear cap-binding complex (CBC) binds to the 5′ caps of RNA polymerase II (RNAPII)-synthesized transcripts and serves as a dynamic interaction platform for a myriad of RNA processing factors that regulate gene expression. While influence of the CBC can extend into the cytoplasm, here we review the roles of the CBC in the nucleus, with a focus on protein-coding genes. We discuss differences between CBC function in yeast and mammals, covering the steps of transcription initiation, release of RNAPII from pausing, transcription elongation, cotranscriptional pre-mRNA splicing, transcription termination, and consequences of spurious transcription. We describe parameters known to control the binding of generic or gene-specific cofactors that regulate CBC activities depending on the process(es) targeted, illustrating how the CBC is an ever-changing choreographer of gene expression.
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Affiliation(s)
- Xavier Rambout
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, New York 14642, USA
| | - Lynne E Maquat
- Department of Biochemistry and Biophysics, School of Medicine and Dentistry, University of Rochester, Rochester, New York 14642, USA.,Center for RNA Biology, University of Rochester, Rochester, New York 14642, USA
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11
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Enwerem III, Elrod ND, Chang CT, Lin A, Ji P, Bohn JA, Levdansky Y, Wagner EJ, Valkov E, Goldstrohm AC. Human Pumilio proteins directly bind the CCR4-NOT deadenylase complex to regulate the transcriptome. RNA (NEW YORK, N.Y.) 2021; 27:445-464. [PMID: 33397688 PMCID: PMC7962487 DOI: 10.1261/rna.078436.120] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Accepted: 12/28/2020] [Indexed: 05/13/2023]
Abstract
Pumilio paralogs, PUM1 and PUM2, are sequence-specific RNA-binding proteins that are essential for vertebrate development and neurological functions. PUM1&2 negatively regulate gene expression by accelerating degradation of specific mRNAs. Here, we determined the repression mechanism and impact of human PUM1&2 on the transcriptome. We identified subunits of the CCR4-NOT (CNOT) deadenylase complex required for stable interaction with PUM1&2 and to elicit CNOT-dependent repression. Isoform-level RNA sequencing revealed broad coregulation of target mRNAs through the PUM-CNOT repression mechanism. Functional dissection of the domains of PUM1&2 identified a conserved amino-terminal region that confers the predominant repressive activity via direct interaction with CNOT. In addition, we show that the mRNA decapping enzyme, DCP2, has an important role in repression by PUM1&2 amino-terminal regions. Our results support a molecular model of repression by human PUM1&2 via direct recruitment of CNOT deadenylation machinery in a decapping-dependent mRNA decay pathway.
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Affiliation(s)
- Isioma I I Enwerem
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
| | - Nathan D Elrod
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Chung-Te Chang
- Department of Biochemistry, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Ai Lin
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Ping Ji
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Jennifer A Bohn
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
| | - Yevgen Levdansky
- Department of Biochemistry, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Eric J Wagner
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, Texas 77550, USA
| | - Eugene Valkov
- Department of Biochemistry, Max Planck Institute for Developmental Biology, 72076 Tübingen, Germany
| | - Aaron C Goldstrohm
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, Minnesota 55455, USA
- Department of Biological Chemistry, University of Michigan, Ann Arbor, Michigan 48109, USA
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12
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The Regulatory Properties of the Ccr4-Not Complex. Cells 2020; 9:cells9112379. [PMID: 33138308 PMCID: PMC7692201 DOI: 10.3390/cells9112379] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Revised: 10/21/2020] [Accepted: 10/26/2020] [Indexed: 12/12/2022] Open
Abstract
The mammalian Ccr4–Not complex, carbon catabolite repression 4 (Ccr4)-negative on TATA-less (Not), is a large, highly conserved, multifunctional assembly of proteins that acts at different cellular levels to regulate gene expression. In the nucleus, it is involved in the regulation of the cell cycle, chromatin modification, activation and inhibition of transcription initiation, control of transcription elongation, RNA export, nuclear RNA surveillance, and DNA damage repair. In the cytoplasm, the Ccr4–Not complex plays a central role in mRNA decay and affects protein quality control. Most of our original knowledge of the Ccr4–Not complex is derived, primarily, from studies in yeast. More recent studies have shown that the mammalian complex has a comparable structure and similar properties. In this review, we summarize the evidence for the multiple roles of both the yeast and mammalian Ccr4–Not complexes, highlighting their similarities.
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13
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Hanet A, Räsch F, Weber R, Ruscica V, Fauser M, Raisch T, Kuzuoğlu-Öztürk D, Chang CT, Bhandari D, Igreja C, Wohlbold L. HELZ directly interacts with CCR4-NOT and causes decay of bound mRNAs. Life Sci Alliance 2019; 2:2/5/e201900405. [PMID: 31570513 PMCID: PMC6769256 DOI: 10.26508/lsa.201900405] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Revised: 09/13/2019] [Accepted: 09/13/2019] [Indexed: 12/11/2022] Open
Abstract
The putative UPF1-like SF1 helicase HELZ directly interacts with the CCR4–NOT deadenylase complex to induce translational repression and 5′-to-3′ decay of bound mRNAs. Eukaryotic superfamily (SF) 1 helicases have been implicated in various aspects of RNA metabolism, including transcription, processing, translation, and degradation. Nevertheless, until now, most human SF1 helicases remain poorly understood. Here, we have functionally and biochemically characterized the role of a putative SF1 helicase termed “helicase with zinc-finger,” or HELZ. We discovered that HELZ associates with various mRNA decay factors, including components of the carbon catabolite repressor 4-negative on TATA box (CCR4–NOT) deadenylase complex in human and Drosophila melanogaster cells. The interaction between HELZ and the CCR4–NOT complex is direct and mediated by extended low-complexity regions in the C-terminal part of the protein. We further reveal that HELZ requires the deadenylase complex to mediate translational repression and decapping-dependent mRNA decay. Finally, transcriptome-wide analysis of Helz-null cells suggests that HELZ has a role in the regulation of the expression of genes associated with the development of the nervous system.
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Affiliation(s)
- Aoife Hanet
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Felix Räsch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Vincenzo Ruscica
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Maria Fauser
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Tobias Raisch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany.,Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Duygu Kuzuoğlu-Öztürk
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany.,Helen Diller Family Cancer Research, University of California San Francisco, San Francisco, CA, USA
| | - Chung-Te Chang
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Dipankar Bhandari
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Lara Wohlbold
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Tübingen, Germany
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14
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Chang CT, Muthukumar S, Weber R, Levdansky Y, Chen Y, Bhandari D, Igreja C, Wohlbold L, Valkov E, Izaurralde E. A low-complexity region in human XRN1 directly recruits deadenylation and decapping factors in 5'-3' messenger RNA decay. Nucleic Acids Res 2019; 47:9282-9295. [PMID: 31340047 PMCID: PMC6753473 DOI: 10.1093/nar/gkz633] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 07/08/2019] [Accepted: 07/15/2019] [Indexed: 12/27/2022] Open
Abstract
XRN1 is the major cytoplasmic exoribonuclease in eukaryotes, which degrades deadenylated and decapped mRNAs in the last step of the 5'-3' mRNA decay pathway. Metazoan XRN1 interacts with decapping factors coupling the final stages of decay. Here, we reveal a direct interaction between XRN1 and the CCR4-NOT deadenylase complex mediated by a low-complexity region in XRN1, which we term the 'C-terminal interacting region' or CIR. The CIR represses reporter mRNA deadenylation in human cells when overexpressed and inhibits CCR4-NOT and isolated CAF1 deadenylase activity in vitro. Through complementation studies in an XRN1-null cell line, we dissect the specific contributions of XRN1 domains and regions toward decay of an mRNA reporter. We observe that XRN1 binding to the decapping activator EDC4 counteracts the dominant negative effect of CIR overexpression on decay. Another decapping activator PatL1 directly interacts with CIR and alleviates the CIR-mediated inhibition of CCR4-NOT activity in vitro. Ribosome profiling revealed that XRN1 loss impacts not only on mRNA levels but also on the translational efficiency of many cellular transcripts likely as a consequence of incomplete decay. Our findings reveal an additional layer of direct interactions in a tightly integrated network of factors mediating deadenylation, decapping and 5'-3' exonucleolytic decay.
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Affiliation(s)
- Chung-Te Chang
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Sowndarya Muthukumar
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Ramona Weber
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Yevgen Levdansky
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Ying Chen
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
- Department of Molecular Biology, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Dipankar Bhandari
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Catia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Lara Wohlbold
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Eugene Valkov
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, Max-Planck-Ring 5, 72076 Tübingen, Germany
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15
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Reconstitution of recombinant human CCR4-NOT reveals molecular insights into regulated deadenylation. Nat Commun 2019; 10:3173. [PMID: 31320642 PMCID: PMC6639331 DOI: 10.1038/s41467-019-11094-z] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 06/20/2019] [Indexed: 02/07/2023] Open
Abstract
CCR4-NOT is a conserved multiprotein complex which regulates eukaryotic gene expression principally via shortening of poly(A) tails of messenger RNA or deadenylation. Here, we reconstitute a complete, recombinant human CCR4-NOT complex. Our reconstitution strategy permits strict compositional control to test mechanistic hypotheses with purified component variants. CCR4-NOT is more active and selective for poly(A) than the isolated exonucleases, CCR4a and CAF1, which have distinct deadenylation profiles in vitro. The exonucleases require at least two out of three conserved non-enzymatic modules (CAF40, NOT10:NOT11 or NOT) for full activity in CCR4-NOT. CAF40 and the NOT10:NOT11 module both bind RNA directly and stimulate deadenylation in a partially redundant manner. Linear motifs from different RNA-binding factors that recruit CCR4-NOT to specific mRNAs via protein-protein interactions with CAF40 can inhibit bulk deadenylation. We reveal an additional layer of regulatory complexity to the human deadenylation machinery, which may prime it either for general or target-specific degradation. The CCR4-NOT complex shortens poly(A) tails of messenger RNAs. By biochemical reconstitution of the entire human CCR4-NOT complex, the authors show the stimulatory roles of non-enzymatic subunits and the importance of the interaction between CAF40 and RNA binding proteins in targeted deadenylation.
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16
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Keskeny C, Raisch T, Sgromo A, Igreja C, Bhandari D, Weichenrieder O, Izaurralde E. A conserved CAF40-binding motif in metazoan NOT4 mediates association with the CCR4-NOT complex. Genes Dev 2019; 33:236-252. [PMID: 30692204 PMCID: PMC6362812 DOI: 10.1101/gad.320952.118] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 12/10/2018] [Indexed: 11/25/2022]
Abstract
The multisubunit CCR4-NOT mRNA deadenylase complex plays important roles in the posttranscriptional regulation of gene expression. The NOT4 E3 ubiquitin ligase is a stable component of the CCR4-NOT complex in yeast but does not copurify with the human or Drosophila melanogaster complex. Here we show that the C-terminal regions of human and D. melanogaster NOT4 contain a conserved sequence motif that directly binds the CAF40 subunit of the CCR4-NOT complex (CAF40-binding motif [CBM]). In addition, nonconserved sequences flanking the CBM also contact other subunits of the complex. Crystal structures of the CBM-CAF40 complex reveal a mutually exclusive binding surface for NOT4 and Roquin or Bag of marbles mRNA regulatory proteins. Furthermore, CAF40 depletion or structure-guided mutagenesis to disrupt the NOT4-CAF40 interaction impairs the ability of NOT4 to elicit decay of tethered reporter mRNAs in cells. Together with additional sequence analyses, our results reveal the molecular basis for the association of metazoan NOT4 with the CCR4-NOT complex and show that it deviates substantially from yeast. They mark the NOT4 ubiquitin ligase as an ancient but nonconstitutive cofactor of the CCR4-NOT deadenylase with potential recruitment and/or effector functions.
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Affiliation(s)
- Csilla Keskeny
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Tobias Raisch
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Annamaria Sgromo
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Cátia Igreja
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Dipankar Bhandari
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Oliver Weichenrieder
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
| | - Elisa Izaurralde
- Department of Biochemistry, Max Planck Institute for Developmental Biology, D-72076 Tübingen, Germany
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