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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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Kern C, Radon C, Wende W, Leitner A, Sträßer K. Cross-linking mass spectrometric analysis of the endogenous TREX complex from Saccharomyces cerevisiae. RNA (NEW YORK, N.Y.) 2023; 29:1870-1880. [PMID: 37699651 PMCID: PMC10653388 DOI: 10.1261/rna.079758.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2023] [Accepted: 08/22/2023] [Indexed: 09/14/2023]
Abstract
The conserved TREX complex has multiple functions in gene expression such as transcription elongation, 3' end processing, mRNP assembly and nuclear mRNA export as well as the maintenance of genomic stability. In Saccharomyces cerevisiae, TREX is composed of the pentameric THO complex, the DEAD-box RNA helicase Sub2, the nuclear mRNA export adaptor Yra1, and the SR-like proteins Gbp2 and Hrb1. Here, we present the structural analysis of the endogenous TREX complex of S. cerevisiae purified from its native environment. To this end, we used cross-linking mass spectrometry to gain structural information on regions of the complex that are not accessible to classical structural biology techniques. We also used negative-stain electron microscopy to investigate the organization of the cross-linked complex used for XL-MS by comparing our endogenous TREX complex with recently published structural models of recombinant THO-Sub2 complexes. According to our analysis, the endogenous yeast TREX complex preferentially assembles into a dimer.
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Affiliation(s)
- Carina Kern
- Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany
| | - Christin Radon
- Institute of Biochemistry and Biology, Department of Biochemistry, University of Potsdam, 14476 Potsdam-Golm, Germany
| | - Wolfgang Wende
- Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany
| | - Alexander Leitner
- Department of Biology, Institute of Molecular Systems Biology, ETH Zurich, 8093 Zurich, Switzerland
| | - Katja Sträßer
- Institute of Biochemistry, FB08, Justus Liebig University, 35392 Giessen, Germany
- Cardio-Pulmonary Institute (CPI), EXC 2026, 35392 Giessen, Germany
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Xie Y, Gao S, Zhang K, Bhat P, Clarke BP, Batten K, Mei M, Gazzara M, Shay JW, Lynch KW, Angelos AE, Hill PS, Ivey AL, Fontoura BMA, Ren Y. Structural basis for high-order complex of SARNP and DDX39B to facilitate mRNP assembly. Cell Rep 2023; 42:112988. [PMID: 37578863 PMCID: PMC10508174 DOI: 10.1016/j.celrep.2023.112988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/10/2023] [Accepted: 07/31/2023] [Indexed: 08/16/2023] Open
Abstract
mRNA in eukaryotic cells is packaged into highly compacted ribonucleoprotein particles (mRNPs) in the nucleus and exported to the cytoplasm for translation. mRNP packaging and export require the evolutionarily conserved transcription-export (TREX) complex. TREX facilitates loading of various RNA-binding proteins on mRNA through the action of its DDX39B subunit. SARNP (Tho1 [transcriptional defect of Hpr1 by overexpression 1] in yeast) is shown to interact with DDX39B and affect mRNA export. The molecular mechanism of how SARNP recognizes DDX39B and functions in mRNP assembly is unclear. Here, we determine the crystal structure of a Tho1/DDX39B/RNA complex, revealing a multivalent interaction mediated by tandem DDX39B interacting motifs in SARNP/Tho1. The high-order complex of SARNP and DDX39B is evolutionarily conserved, and human SARNP can engage with five DDX39B molecules. RNA sequencing (RNA-seq) from SARNP knockdown cells shows the most affected RNAs in export are GC rich. Our work suggests the role of the high-order SARNP/DDX39B/RNA complex in mRNP assembly and export.
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Affiliation(s)
- Yihu Xie
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Shengyan Gao
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Ke Zhang
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Prasanna Bhat
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Bradley P Clarke
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Kimberly Batten
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Menghan Mei
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Matthew Gazzara
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Jerry W Shay
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA
| | - Kristen W Lynch
- Department of Biochemistry and Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Alexia E Angelos
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Pate S Hill
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Austin L Ivey
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA
| | - Beatriz M A Fontoura
- Department of Cell Biology, University of Texas Southwestern Medical Center, Dallas, TX 75390-9039, USA.
| | - Yi Ren
- Department of Biochemistry, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA; Center for Structural Biology, Vanderbilt University School of Medicine, Nashville, TN 37232-0146, USA.
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Keil P, Wulf A, Kachariya N, Reuscher S, Hühn K, Silbern I, Altmüller J, Keller M, Stehle R, Zarnack K, Sattler M, Urlaub H, Sträßer K. Npl3 functions in mRNP assembly by recruitment of mRNP components to the transcription site and their transfer onto the mRNA. Nucleic Acids Res 2022; 51:831-851. [PMID: 36583366 PMCID: PMC9881175 DOI: 10.1093/nar/gkac1206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 11/25/2022] [Accepted: 12/07/2022] [Indexed: 12/31/2022] Open
Abstract
RNA-binding proteins (RBPs) control every RNA metabolic process by multiple protein-RNA and protein-protein interactions. Their roles have largely been analyzed by crude mutations, which abrogate multiple functions at once and likely impact the structural integrity of the large ribonucleoprotein particles (RNPs) these proteins function in. Using UV-induced RNA-protein crosslinking of entire cells, protein complex purification and mass spectrometric analysis, we identified >100 in vivo RNA crosslinks in 16 nuclear mRNP components in Saccharomyces cerevisiae. For functional analysis, we chose Npl3, which displayed crosslinks in its two RNA recognition motifs (RRMs) and in the connecting flexible linker region. Both RRM domains and the linker uniquely contribute to RNA recognition as revealed by NMR and structural analyses. Interestingly, mutations in these regions cause different phenotypes, indicating distinct functions of the different RNA-binding domains. Notably, an npl3-Linker mutation strongly impairs recruitment of several mRNP components to chromatin and incorporation of other mRNP components into nuclear mRNPs, establishing a so far unknown function of Npl3 in nuclear mRNP assembly. Taken together, our integrative analysis uncovers a specific function of the RNA-binding activity of the nuclear mRNP component Npl3. This approach can be readily applied to RBPs in any RNA metabolic process.
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Affiliation(s)
| | | | | | - Samira Reuscher
- Buchmann Institute for Molecular Life Sciences (BMLS) & Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt a.M., Germany
| | - Kristin Hühn
- Institute of Biochemistry, FB08, Justus Liebig University Giessen, Heinrich-Buff-Ring 17, 35392 Giessen, Germany
| | - Ivan Silbern
- Max Planck Institute for Multidisciplinary Sciences, Am Fassberg 11, 37077 Goettingen, University Medical Center Goettingen, Institute of Clinical Chemistry, Robert-Koch-Strasse 40, 37075 Goettingen, Germany
| | - Janine Altmüller
- Cologne Center for Genomics (CCG), University of Cologne, Weyertal 115b, 50931 Cologne, Germany,Technology platform genomics, Berlin Institute of Health at Charité - Universitätsmedizin Berlin and Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Mario Keller
- Buchmann Institute for Molecular Life Sciences (BMLS) & Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt a.M., Germany
| | - Ralf Stehle
- Bavarian NMR Center (BNMRZ), Department of Bioscience, School of Natural Sciences, Technical University of Munich, Lichtenbergstrasse 4, 85748 Garching, Germany,Institute of Structural Biology, Helmholtz Center Munich, Ingolstaedter Landstrasse 1, 85764 Neuherberg, Germany
| | - Kathi Zarnack
- Buchmann Institute for Molecular Life Sciences (BMLS) & Institute of Molecular Biosciences, Goethe University Frankfurt, Max-von-Laue-Strasse 15, 60438 Frankfurt a.M., Germany,Cardio-Pulmonary Institute (CPI), EXC 2026, 35392 Giessen, Germany
| | | | | | - Katja Sträßer
- To whom correspondence should be addressed. Tel: +49 641 99 35400; Fax: +49 641 99 35409;
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