1
|
Jagtap PKA, Müller M, Kiss AE, Thomae AW, Lapouge K, Beck M, Becker PB, Hennig J. Structural basis of RNA-induced autoregulation of the DExH-type RNA helicase maleless. Mol Cell 2023; 83:4318-4333.e10. [PMID: 37989319 DOI: 10.1016/j.molcel.2023.10.026] [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: 11/12/2022] [Revised: 07/27/2023] [Accepted: 10/18/2023] [Indexed: 11/23/2023]
Abstract
RNA unwinding by DExH-type helicases underlies most RNA metabolism and function. It remains unresolved if and how the basic unwinding reaction of helicases is regulated by auxiliary domains. We explored the interplay between the RecA and auxiliary domains of the RNA helicase maleless (MLE) from Drosophila using structural and functional studies. We discovered that MLE exists in a dsRNA-bound open conformation and that the auxiliary dsRBD2 domain aligns the substrate RNA with the accessible helicase tunnel. In an ATP-dependent manner, dsRBD2 associates with the helicase module, leading to tunnel closure around ssRNA. Furthermore, our structures provide a rationale for blunt-ended dsRNA unwinding and 3'-5' translocation by MLE. Structure-based MLE mutations confirm the functional relevance of our model for RNA unwinding. Our findings contribute to our understanding of the fundamental mechanics of auxiliary domains in DExH helicase MLE, which serves as a model for its human ortholog and potential therapeutic target, DHX9/RHA.
Collapse
Affiliation(s)
- Pravin Kumar Ankush Jagtap
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Chair of Biochemistry IV, Biophysical Chemistry, University of Bayreuth, Bayreuth, Germany.
| | - Marisa Müller
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Anna E Kiss
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Andreas W Thomae
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany; Core Facility Bioimaging at the Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Karine Lapouge
- Protein Expression and Purification Core Facility, EMBL Heidelberg, 69117 Heidelberg, Germany
| | - Martin Beck
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Department of Molecular Sociology, Max Planck Institute of Biophysics, 60438 Frankfurt am Main, Germany
| | - Peter B Becker
- Molecular Biology Division, Biomedical Center, LMU Munich, 82152 Planegg-Martinsried, Germany
| | - Janosch Hennig
- Structural and Computational Biology Unit, EMBL Heidelberg, Meyerhofstraße 1, 69117 Heidelberg, Germany; Chair of Biochemistry IV, Biophysical Chemistry, University of Bayreuth, Bayreuth, Germany.
| |
Collapse
|
2
|
Enders M, Neumann P, Dickmanns A, Ficner R. Structure and function of spliceosomal DEAH-box ATPases. Biol Chem 2023; 404:851-866. [PMID: 37441768 DOI: 10.1515/hsz-2023-0157] [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: 03/10/2023] [Accepted: 07/04/2023] [Indexed: 07/15/2023]
Abstract
Splicing of precursor mRNAs is a hallmark of eukaryotic cells, performed by a huge macromolecular machine, the spliceosome. Four DEAH-box ATPases are essential components of the spliceosome, which play an important role in the spliceosome activation, the splicing reaction, the release of the spliced mRNA and intron lariat, and the disassembly of the spliceosome. An integrative approach comprising X-ray crystallography, single particle cryo electron microscopy, single molecule FRET, and molecular dynamics simulations provided deep insights into the structure, dynamics and function of the spliceosomal DEAH-box ATPases.
Collapse
Affiliation(s)
- Marieke Enders
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| | - Piotr Neumann
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| | - Achim Dickmanns
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, Göttingen Center for Molecular Biosciences (GZMB), Georg-August-University Göttingen, Justus-von-Liebig-Weg 11, D-37077 Göttingen, Germany
| |
Collapse
|
3
|
Osorio Garcia MA, Wood EA, Keck JL, Cox MM. Interaction with single-stranded DNA-binding protein (SSB) modulates Escherichia coli RadD DNA repair activities. J Biol Chem 2023; 299:104773. [PMID: 37142225 DOI: 10.1016/j.jbc.2023.104773] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 04/19/2023] [Accepted: 04/20/2023] [Indexed: 05/06/2023] Open
Abstract
The bacterial RadD enzyme is important for multiple genome maintenance pathways, including RecA DNA strand exchange and RecA-independent suppression of DNA crossover template switching. However, much remains unknown about the precise roles of RadD. One potential clue into RadD mechanisms is its direct interaction with the single-stranded DNA binding protein (SSB), which coats single-stranded DNA exposed during genome maintenance reactions in cells. Interaction with SSB stimulates the ATPase activity of RadD. To probe the mechanism and importance of RadD:SSB complex formation, we identified a pocket on RadD that is essential for binding SSB. In a mechanism shared with many other SSB-interacting proteins, RadD uses a hydrophobic pocket framed by basic residues to bind the C-terminal end of SSB. We found that RadD variants that substitute acidic residues for basic residues in the SSB binding site impair RadD:SSB complex formation and eliminate SSB stimulation of RadD ATPase activity in vitro. Additionally, mutant E. coli strains carrying charge reversal radD changes display increased sensitivity to DNA damaging agents synergistically with deletions of radA and recG, although the phenotypes of the SSB-binding radD mutants are not as severe as a full radD deletion. This suggests that cellular RadD requires an intact the interaction with SSB for full RadD function.
Collapse
Affiliation(s)
| | - Elizabeth A Wood
- Department of Biochemistry, University of Wisconsin, Madison, Madison, WI 53706
| | - James L Keck
- Department of Biomolecular Chemistry, University of Wisconsin School of Medicine and Public Health, Madison, WI, 53706, USA.
| | - Michael M Cox
- Department of Biochemistry, University of Wisconsin, Madison, Madison, WI 53706.
| |
Collapse
|
4
|
Yao J, Cai Y, Chen Z, Wang X, Lai X, Pan L, Li Y, Wang S. Dhx15 regulates zebrafish intestinal development through the Wnt signaling pathway. Genomics 2023; 115:110578. [PMID: 36775210 DOI: 10.1016/j.ygeno.2023.110578] [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: 08/08/2022] [Revised: 02/04/2023] [Accepted: 02/08/2023] [Indexed: 02/12/2023]
Abstract
DEAH-box helicase 15 (DHX15) is ATP-dependent RNA helicase which is known for its role in RNA metabolism. Recent studies reported DHX15 involves in the intestinal immunity. However, the role of DHX15 (or RNA helicase) in intestinal development is poorly understood. Here, we revealed an unidentified role for dhx15 in regulating zebrafish intestinal development. We found the profound intestinal defects in dhx15 knockout zebrafish. Decreased proliferation and increased apoptosis of the intestine cells were observed when dhx15 were deleted. Further RNA genome wide analysis and qRT-PCR analysis showed the Wnt signaling pathway is down-regulated in the dhx15 knockout zebrafish. Thus, we concluded that dhx15 regulates zebrafish intestinal development through the Wnt signaling pathway. Here, we provided new insights into the role of dhx15 in intestinal development beyond its well-characterized role in intestinal immunity.
Collapse
Affiliation(s)
- Jinpeng Yao
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Yuanhua Cai
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China; Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Zhixiang Chen
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Xuechun Wang
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China
| | - Xiaolin Lai
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China; Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Lili Pan
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China; Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Yang Li
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China; Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China
| | - Shaoyuan Wang
- Union Clinical Medical Colleges, Fujian Medical University, Fuzhou, China; Department of Hematology, Fujian Institute of Hematology, Fujian Provincial Key Laboratory on Hematology, Fujian Medical University Union Hospital, Fuzhou, China.
| |
Collapse
|
5
|
Bohnsack KE, Kanwal N, Bohnsack MT. Prp43/DHX15 exemplify RNA helicase multifunctionality in the gene expression network. Nucleic Acids Res 2022; 50:9012-9022. [PMID: 35993807 PMCID: PMC9458436 DOI: 10.1093/nar/gkac687] [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: 05/17/2022] [Revised: 07/10/2022] [Accepted: 08/01/2022] [Indexed: 12/24/2022] Open
Abstract
Dynamic regulation of RNA folding and structure is critical for the biogenesis and function of RNAs and ribonucleoprotein (RNP) complexes. Through their nucleotide triphosphate-dependent remodelling functions, RNA helicases are key modulators of RNA/RNP structure. While some RNA helicases are dedicated to a specific target RNA, others are multifunctional and engage numerous substrate RNAs in different aspects of RNA metabolism. The discovery of such multitasking RNA helicases raises the intriguing question of how these enzymes can act on diverse RNAs but also maintain specificity for their particular targets within the RNA-dense cellular environment. Furthermore, the identification of RNA helicases that sit at the nexus between different aspects of RNA metabolism raises the possibility that they mediate cross-regulation of different cellular processes. Prominent and extensively characterized multifunctional DEAH/RHA-box RNA helicases are DHX15 and its Saccharomyces cerevisiae (yeast) homologue Prp43. Due to their central roles in key cellular processes, these enzymes have also served as prototypes for mechanistic studies elucidating the mode of action of this type of enzyme. Here, we summarize the current knowledge on the structure, regulation and cellular functions of Prp43/DHX15, and discuss the general concept and implications of RNA helicase multifunctionality.
Collapse
Affiliation(s)
- Katherine E Bohnsack
- Correspondence may also be addressed to Katherine E. Bohnsack. Tel: +49 551 3969305; Fax: +49 551 395960;
| | - Nidhi Kanwal
- Department of Molecular Biology, University Medical Center Göttingen, Humboldtallee 23, 37073 Göttingen, Germany
| | - Markus T Bohnsack
- To whom correspondence should be addressed. Tel: +49 551 395968; Fax: +49 551 395960;
| |
Collapse
|
6
|
Du Pont KE, McCullagh M, Geiss BJ. Conserved motifs in the flavivirus NS3 RNA helicase enzyme. WILEY INTERDISCIPLINARY REVIEWS. RNA 2022; 13:e1688. [PMID: 34472205 PMCID: PMC8888775 DOI: 10.1002/wrna.1688] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 07/29/2021] [Accepted: 08/02/2021] [Indexed: 01/04/2023]
Abstract
Flaviviruses are a major health concern because over half of the world population is at risk of infection and there are very few antiviral therapeutics to treat diseases resulting from infection. Replication is an essential part of the flavivirus survival. One of the viral proteins, NS3 helicase, is critical for unwinding the double stranded RNA intermediate during flaviviral replication. The helicase performs the unwinding of the viral RNA intermediate structure in an ATP-dependent manner. NS3 helicase is a member of the Viral/DEAH-like subfamily of the superfamily 2 helicase containing eight highly conserved structural motifs (I, Ia, II, III, IV, IVa, V, and VI) localized between the ATP-binding and RNA-binding pockets. Of these structural motifs only three are well characterized for function in flaviviruses (I, II, and VI). The roles of the other structural motifs are not well understood for NS3 helicase function, but comparison of NS3 with other superfamily 2 helicases within the viral/DEAH-like, DEAH/RHA, and DEAD-box subfamilies can be used to elucidate the roles of these structural motifs in the flavivirus NS3 helicase. This review aims to summarize the role of each conserved structural motif within flavivirus NS3 in RNA helicase function. This article is categorized under: RNA Interactions with Proteins and Other Molecules > Protein-RNA Interactions: Functional Implications RNA in Disease and Development > RNA in Disease.
Collapse
Affiliation(s)
- Kelly E. Du Pont
- Department of Chemistry, Colorado State University, Fort Collins, Colorado, USA
| | - Martin McCullagh
- Department of Chemistry, Oklahoma State University, Stillwater, Oklahoma, USA
| | - Brian J. Geiss
- Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,Arthropod-borne and Infectious Diseases Laboratory, Department of Microbiology, Immunology and Pathology, Colorado State University, Fort Collins, Colorado, USA,School of Biomedical Engineering, Colorado State University, Fort Collins, Colorado, USA
| |
Collapse
|
7
|
Mitterer V, Pertschy B. RNA folding and functions of RNA helicases in ribosome biogenesis. RNA Biol 2022; 19:781-810. [PMID: 35678541 PMCID: PMC9196750 DOI: 10.1080/15476286.2022.2079890] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/16/2022] [Indexed: 11/13/2022] Open
Abstract
Eukaryotic ribosome biogenesis involves the synthesis of ribosomal RNA (rRNA) and its stepwise folding into the unique structure present in mature ribosomes. rRNA folding starts already co-transcriptionally in the nucleolus and continues when pre-ribosomal particles further maturate in the nucleolus and upon their transit to the nucleoplasm and cytoplasm. While the approximate order of folding of rRNA subdomains is known, especially from cryo-EM structures of pre-ribosomal particles, the actual mechanisms of rRNA folding are less well understood. Both small nucleolar RNAs (snoRNAs) and proteins have been implicated in rRNA folding. snoRNAs hybridize to precursor rRNAs (pre-rRNAs) and thereby prevent premature folding of the respective rRNA elements. Ribosomal proteins (r-proteins) and ribosome assembly factors might have a similar function by binding to rRNA elements and preventing their premature folding. Besides that, a small group of ribosome assembly factors are thought to play a more active role in rRNA folding. In particular, multiple RNA helicases participate in individual ribosome assembly steps, where they are believed to coordinate RNA folding/unfolding events or the release of proteins from the rRNA. In this review, we summarize the current knowledge on mechanisms of RNA folding and on the specific function of the individual RNA helicases involved. As the yeast Saccharomyces cerevisiae is the organism in which ribosome biogenesis and the role of RNA helicases in this process is best studied, we focused our review on insights from this model organism, but also make comparisons to other organisms where applicable.
Collapse
Affiliation(s)
- Valentin Mitterer
- Biochemistry Center, Heidelberg University, Im Neuenheimer Feld 328, Heidelberg, Germany
- BioTechMed-Graz, Graz, Austria
| | - Brigitte Pertschy
- BioTechMed-Graz, Graz, Austria
- Institute of Molecular Biosciences, University of Graz, Humboldtstrasse 50, Graz, Austria
| |
Collapse
|
8
|
De Bortoli F, Espinosa S, Zhao R. DEAH-Box RNA Helicases in Pre-mRNA Splicing. Trends Biochem Sci 2021; 46:225-238. [PMID: 33272784 PMCID: PMC8112905 DOI: 10.1016/j.tibs.2020.10.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Revised: 10/04/2020] [Accepted: 10/26/2020] [Indexed: 11/25/2022]
Abstract
In eukaryotic cells, pre-mRNA splicing is catalyzed by the spliceosome, a highly dynamic molecular machinery that undergoes dramatic conformational and compositional rearrangements throughout the splicing cycle. These crucial rearrangements are largely driven by eight DExD/H-box RNA helicases. Interestingly, the four helicases participating in the late stages of splicing are all DEAH-box helicases that share structural similarities. This review aims to provide an overview of the structure and function of these DEAH-box helicases, including new information provided by recent cryo-electron microscopy structures of the spliceosomal complexes.
Collapse
Affiliation(s)
- Francesca De Bortoli
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Sara Espinosa
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA
| | - Rui Zhao
- Department of Biochemistry and Molecular Genetics, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, CO, USA.
| |
Collapse
|
9
|
Chen W, Hu Y, Lang CF, Brown JS, Schwabach S, Song X, Zhang Y, Munro E, Bennett K, Zhang D, Lee HC. The Dynamics of P Granule Liquid Droplets Are Regulated by the Caenorhabditis elegans Germline RNA Helicase GLH-1 via Its ATP Hydrolysis Cycle. Genetics 2020; 215:421-434. [PMID: 32245789 PMCID: PMC7268986 DOI: 10.1534/genetics.120.303052] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 03/12/2020] [Indexed: 02/06/2023] Open
Abstract
P granules are phase-separated liquid droplets that play important roles in the maintenance of germ cell fate in Caenorhabditis elegans Both the localization and formation of P granules are highly dynamic, but mechanisms that regulate such processes remain poorly understood. Here, we show evidence that the VASA-like germline RNA helicase GLH-1 couples distinct steps of its ATPase hydrolysis cycle to control the formation and disassembly of P granules. In addition, we found that the phenylalanine-glycine-glycine repeats in GLH-1 promote its localization at the perinucleus. Proteomic analyses of the GLH-1 complex with a GLH-1 mutation that interferes with P granule disassembly revealed transient interactions of GLH-1 with several Argonautes and RNA-binding proteins. Finally, we found that defects in recruiting the P granule component PRG-1 to perinuclear foci in the adult germline correlate with the fertility defects observed in various GLH-1 mutants. Together, our results highlight the versatile roles of an RNA helicase in controlling the formation of liquid droplets in space and time.
Collapse
Affiliation(s)
- Wenjun Chen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | - Yabing Hu
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China 430074
| | - Charles F Lang
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | - Jordan S Brown
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | - Sierra Schwabach
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | - Xiaoyan Song
- Department of Clinical Laboratory, The Third Affiliated Hospital of Zhengzhou University, China 450052
| | - Ying Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China 430074
| | - Edwin Munro
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| | - Karen Bennett
- Department of Molecular Microbiology and Immunology, University of Missouri School of Medicine, Columbia, Missouri 65212
| | - Donglei Zhang
- Department of Biochemistry and Molecular Biology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China 430074
| | - Heng-Chi Lee
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637
| |
Collapse
|
10
|
Abstract
RNA helicases exert mechanical force that changes RNA configurations in many essential cellular pathways, e.g., during mRNA maturation or assembly of ribosomes. DEAH helicases work by translocating along RNA and thereby unwind RNA duplexes or dissociate bound proteins. Because DEAH proteins are poor enzymes without intrinsic selectivity for target RNAs, they require adapter proteins that recruit them to functional sites and enhance their catalytic activity. One essential class of DEAH activators is formed by G-patch proteins, which bind helicases via their eponymous glycine-rich motif. We solved the structure of a G-patch bound to helicase DHX15. Our analysis suggests that G-patches tether mobile sections of DEAH helicases together and activate them by stabilizing a functional conformation with high RNA affinity. RNA helicases of the DEAH/RHA family are involved in many essential cellular processes, such as splicing or ribosome biogenesis, where they remodel large RNA–protein complexes to facilitate transitions to the next intermediate. DEAH helicases couple adenosine triphosphate (ATP) hydrolysis to conformational changes of their catalytic core. This movement results in translocation along RNA, which is held in place by auxiliary C-terminal domains. The activity of DEAH proteins is strongly enhanced by the large and diverse class of G-patch activators. Despite their central roles in RNA metabolism, insight into the molecular basis of G-patch–mediated helicase activation is missing. Here, we have solved the structure of human helicase DHX15/Prp43, which has a dual role in splicing and ribosome assembly, in complex with the G-patch motif of the ribosome biogenesis factor NKRF. The G-patch motif binds in an extended conformation across the helicase surface. It tethers the catalytic core to the flexibly attached C-terminal domains, thereby fixing a conformation that is compatible with RNA binding. Structures in the presence or absence of adenosine diphosphate (ADP) suggest that motions of the catalytic core, which are required for ATP binding, are still permitted. Concomitantly, RNA affinity, helicase, and ATPase activity of DHX15 are increased when G-patch is bound. Mutations that detach one end of the tether but maintain overall binding severely impair this enhancement. Collectively, our data suggest that the G-patch motif acts like a flexible brace between dynamic portions of DHX15 that restricts excessive domain motions but maintains sufficient flexibility for catalysis.
Collapse
|
11
|
Srinivasan S, Liu Z, Chuenchor W, Xiao TS, Jankowsky E. Function of Auxiliary Domains of the DEAH/RHA Helicase DHX36 in RNA Remodeling. J Mol Biol 2020; 432:2217-2231. [PMID: 32087197 DOI: 10.1016/j.jmb.2020.02.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2019] [Revised: 01/28/2020] [Accepted: 02/07/2020] [Indexed: 01/06/2023]
Abstract
The DEAH/RHA helicase DHX36 has been linked to cellular RNA and DNA quadruplex structures and to AU-rich RNA elements. In vitro, DHX36 remodels DNA and RNA quadruplex structures and unwinds DNA duplexes in an ATP-dependent manner. DHX36 contains the superfamily 2 helicase core and several auxiliary domains that are conserved in orthologs of the enzyme. The role of these auxiliary domains for the enzymatic function of DHX36 is not well understood. Here, we combine structural and biochemical studies to define the function of three auxiliary domains that contact nucleic acid. We first report the crystal structure of mouse DHX36 bound to ADP. The structure reveals an overall architecture of mouse DHX36 that is similar to previously reported architectures of fly and bovine DHX36. In addition, our structure shows conformational changes that accompany stages of the ATP-binding and hydrolysis cycle. We then examine the roles of the DHX36-specific motif (DSM), the OB-fold, and a conserved β-hairpin (β-HP) in mouse DHX36 in the remodeling of RNA structures. We demonstrate and characterize RNA duplex unwinding for DHX36 and examine the remodeling of inter- and intramolecular RNA quadruplex structures. We find that the DSM not only functions as a quadruplex binding adaptor but also promotes the remodeling of RNA duplex and quadruplex structures. The OB-fold and the β-HP contribute to RNA binding. Both domains are also essential for remodeling RNA quadruplex and duplex structures. Our data reveal roles of auxiliary domains for multiple steps of the nucleic acid remodeling reactions.
Collapse
Affiliation(s)
| | - Zhonghua Liu
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | | | - Tsan Sam Xiao
- Department of Pathology, School of Medicine, Case Western Reserve University, Cleveland, OH, USA; Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Eckhard Jankowsky
- Center for RNA Science and Therapeutics, USA; Case Comprehensive Cancer Center, School of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
12
|
Hausmann S, Geiser J, Vadas O, Ducret V, Perron K, Valentini M. Auxiliary domains of the HrpB bacterial DExH-box helicase shape its RNA preferences. RNA Biol 2020; 17:637-650. [PMID: 32050838 PMCID: PMC7237152 DOI: 10.1080/15476286.2020.1720376] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
RNA helicases are fundamental players in RNA metabolism: they remodel RNA secondary structures and arrange ribonucleoprotein complexes. While DExH-box RNA helicases function in ribosome biogenesis and splicing in eukaryotes, information is scarce about bacterial homologs. HrpB is the only bacterial DExH-box protein whose structure is solved. Besides the catalytic core, HrpB possesses three accessory domains, conserved in all DExH-box helicases, plus a unique C-terminal extension (CTE). The function of these auxiliary domains remains unknown. Here, we characterize genetically and biochemically Pseudomonas aeruginosa HrpB homolog. We reveal that the auxiliary domains shape HrpB RNA preferences, affecting RNA species recognition and catalytic activity. We show that, among several types of RNAs, the single-stranded poly(A) and the highly structured MS2 RNA strongly stimulate HrpB ATPase activity. In addition, deleting the CTE affects only stimulation by structured RNAs like MS2 and rRNAs, while deletion of accessory domains results in gain of poly(U)-dependent activity. Finally, using hydrogen-deuterium exchange, we dissect the molecular details of HrpB interaction with poly(A) and MS2 RNAs. The catalytic core interacts with both RNAs, triggering a conformational change that reorients HrpB. Regions within the accessory domains and CTE are, instead, specifically responsive to MS2. Altogether, we demonstrate that in bacteria, like in eukaryotes, DExH-box helicase auxiliary domains are indispensable for RNA handling.
Collapse
Affiliation(s)
- Stéphane Hausmann
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Johan Geiser
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Oscar Vadas
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland.,Protein Production Platform, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| | - Verena Ducret
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Karl Perron
- Microbiology Unit, Department of Botany and Plant Biology, University of Geneva, Geneva, Switzerland
| | - Martina Valentini
- Department of Microbiology and Molecular Medicine, CMU, Faculty of Medicine, University of Geneva, Geneva, Switzerland
| |
Collapse
|
13
|
Hamann F, Enders M, Ficner R. Structural basis for RNA translocation by DEAH-box ATPases. Nucleic Acids Res 2019; 47:4349-4362. [PMID: 30828714 PMCID: PMC6486627 DOI: 10.1093/nar/gkz150] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/28/2019] [Accepted: 02/22/2019] [Indexed: 12/15/2022] Open
Abstract
DEAH-box adenosine triphosphatases (ATPases) play a crucial role in the spliceosome-mediated excision of pre-mRNA introns. Recent spliceosomal cryo-EM structures suggest that these proteins utilize translocation to apply forces on ssRNAs rather than direct RNA duplex unwinding to ensure global rearrangements. By solving the crystal structure of Prp22 in different adenosine nucleotide-free states, we identified two missing conformational snapshots of genuine DEAH-box ATPases that help to unravel the molecular mechanism of translocation for this protein family. The intrinsic mobility of the RecA2 domain in the absence of adenosine di- or triphosphate (ADP/ATP) and RNA enables DEAH-box ATPases to adopt different open conformations of the helicase core. The presence of RNA suppresses this mobility and stabilizes one defined open conformation when no adenosine nucleotide is bound. A comparison of this novel conformation with the ATP-bound state of Prp43 reveals that these ATPases cycle between closed and open conformations of the helicase core, which accommodate either a four- or five-nucleotide stack in the RNA-binding tunnel, respectively. The continuous repetition of these states enables these proteins to translocate in 3′-5′ direction along an ssRNA with a step-size of one RNA nucleotide per hydrolyzed ATP. This ATP-driven motor function is maintained by a serine in the conserved motif V that senses the catalytic state and accordingly positions the RecA2 domain.
Collapse
Affiliation(s)
- Florian Hamann
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Marieke Enders
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Goettingen, Justus-von-Liebig-Weg 11, 37077 Goettingen, Germany
| |
Collapse
|
14
|
Toroney R, Nielsen KH, Staley JP. Termination of pre-mRNA splicing requires that the ATPase and RNA unwindase Prp43p acts on the catalytic snRNA U6. Genes Dev 2019; 33:1555-1574. [PMID: 31558568 PMCID: PMC6824469 DOI: 10.1101/gad.328294.119] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2019] [Accepted: 09/03/2019] [Indexed: 11/25/2022]
Abstract
In this study, Toroney et al. set out to identify the mechanism of Prp43p action in splicing. The authors use biochemical approaches to demonstrate that the 3' end of U6 acts as the key substrate by which Prp43p promotes disassembly and intron release, thereby terminating splicing. The termination of pre-mRNA splicing functions to discard suboptimal substrates, thereby enhancing fidelity, and to release excised introns in a manner coupled to spliceosome disassembly, thereby allowing recycling. The mechanism of termination, including the RNA target of the DEAH-box ATPase Prp43p, remains ambiguous. We discovered a critical role for nucleotides at the 3′ end of the catalytic U6 small nuclear RNA in splicing termination. Although conserved sequence at the 3′ end is not required, 2′ hydroxyls are, paralleling requirements for Prp43p biochemical activities. Although the 3′ end of U6 is not required for recruiting Prp43p to the spliceosome, the 3′ end cross-links directly to Prp43p in an RNA-dependent manner. Our data indicate a mechanism of splicing termination in which Prp43p translocates along U6 from the 3′ end to disassemble the spliceosome and thereby release suboptimal substrates or excised introns. This mechanism reveals that the spliceosome becomes primed for termination at the same stage it becomes activated for catalysis, implying a requirement for stringent control of spliceosome activity within the cell.
Collapse
Affiliation(s)
- Rebecca Toroney
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
| | - Klaus H Nielsen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Illinois 60637, USA
| |
Collapse
|
15
|
Vijayakumari D, Sharma AK, Bawa PS, Kumar R, Srinivasan S, Vijayraghavan U. Early splicing functions of fission yeast Prp16 and its unexpected requirement for gene Silencing is governed by intronic features. RNA Biol 2019; 16:754-769. [PMID: 30810475 DOI: 10.1080/15476286.2019.1585737] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022] Open
Abstract
Prp16 is a DEAH box pre-mRNA splicing factor that triggers a key spliceosome conformational switch to facilitate second step splicing in Saccharomyces cerevisiae. However, Prp16 functions are largely unexplored in Schizosaccharomyces pombe, an attractive model with exon-intron architecture more relevant to several other eukaryotes. Here, we generated mis-sense alleles in SpPrp16 whose consequences on genome-wide splicing uncover its nearly global splicing role with only a small subset of unaffected introns. Prp16 dependent and independent intron categories displayed a striking difference in the strength of intronic 5' splice site (5'SS)-U6 snRNA and branch site (BS)-U2 snRNA interactions. Selective weakening of these interactions could convert a Prp16 dependent intron into an independent one. These results point to the role of SpPrp16 in destabilizing 5'SS-U6snRNA and BS-U2snRNA interactions which plausibly trigger structural alterations in the spliceosome to facilitate first step catalysis. Our data suggest that SpPrp16 interactions with early acting factors, its enzymatic activities and association with intronic elements collectively account for efficient and accurate first step catalysis. In addition to splicing derangements in the spprp16F528S mutant, we show that SpPrp16 influences cell cycle progression and centromeric heterochromatinization. We propose that strong 5'SS-U6 snRNA and BS-U2 snRNA complementarity of intron-like elements in non-coding RNAs which lead to complete splicing arrest and impaired Seb1 functions at the pericentromeric loci may cumulatively account for the heterochromatin defects in spprp16F528S cells. These findings suggest that the diverse Prp16 functions within a genome are likely governed by its intronic features that influence splice site-snRNA interaction strength.
Collapse
Affiliation(s)
- Drisya Vijayakumari
- a Department of Microbiology and Cell Biology , Indian Institute of Science , Bangalore , India
| | - Amit Kumar Sharma
- a Department of Microbiology and Cell Biology , Indian Institute of Science , Bangalore , India
| | | | - Rakesh Kumar
- a Department of Microbiology and Cell Biology , Indian Institute of Science , Bangalore , India
| | | | - Usha Vijayraghavan
- a Department of Microbiology and Cell Biology , Indian Institute of Science , Bangalore , India
| |
Collapse
|
16
|
Structures of the human spliceosomes before and after release of the ligated exon. Cell Res 2019; 29:274-285. [PMID: 30728453 PMCID: PMC6461851 DOI: 10.1038/s41422-019-0143-x] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2018] [Accepted: 01/14/2019] [Indexed: 11/08/2022] Open
Abstract
Pre-mRNA splicing is executed by the spliceosome, which has eight major functional states each with distinct composition. Five of these eight human spliceosomal complexes, all preceding exon ligation, have been structurally characterized. In this study, we report the cryo-electron microscopy structures of the human post-catalytic spliceosome (P complex) and intron lariat spliceosome (ILS) at average resolutions of 3.0 and 2.9 Å, respectively. In the P complex, the ligated exon remains anchored to loop I of U5 small nuclear RNA, and the 3′-splice site is recognized by the junction between the 5′-splice site and the branch point sequence. The ATPase/helicase Prp22, along with the ligated exon and eight other proteins, are dissociated in the P-to-ILS transition. Intriguingly, the ILS complex exists in two distinct conformations, one with the ATPase/helicase Prp43 and one without. Comparison of these three late-stage human spliceosomes reveals mechanistic insights into exon release and spliceosome disassembly.
Collapse
|
17
|
Pietrzyk-Brzezinska AJ, Absmeier E, Klauck E, Wen Y, Antelmann H, Wahl MC. Crystal Structure of the Escherichia coli DExH-Box NTPase HrpB. Structure 2018; 26:1462-1473.e4. [PMID: 30174149 DOI: 10.1016/j.str.2018.07.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2018] [Revised: 06/27/2018] [Accepted: 07/25/2018] [Indexed: 10/28/2022]
Abstract
Eukaryotic DExH-box proteins are important post-transcriptional gene regulators, many of which employ RNA-stimulated nucleoside triphosphatase activity to remodel RNAs or ribonucleoprotein complexes. However, bacterial DExH-box proteins are structurally and functionally poorly characterized. We report the crystal structure of the Escherichia coli DExH-box protein HrpB. A globular head is composed of dual RecA, winged-helix, helical bundle and oligonucleotide/oligosaccharide-binding domains, resembling a compact version of eukaryotic DExH-box proteins. Additionally, HrpB harbors a C-terminal region not found in proteins with known structure, which bestows the protein with unique interaction potential. Interaction and activity assays showed that the protein binds RNA but not DNA, hydrolyzes all nucleoside triphosphates in an RNA-stimulated manner, but does not unwind diverse model RNAs in vitro. These observations can be rationalized by detailed comparisons with structurally characterized eukaryotic DExH-box proteins. Comparative phenotypic analyses of an E. coli hrpB knockout mutant suggested diverse functions of HrpB homologs in different bacteria.
Collapse
Affiliation(s)
| | - Eva Absmeier
- Freie Universität Berlin, Laboratory of Structural Biochemistry, 14195 Berlin, Germany
| | - Eberhard Klauck
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Yanlin Wen
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Haike Antelmann
- Freie Universität Berlin, Institute for Biology - Microbiology, 14195 Berlin, Germany
| | - Markus C Wahl
- Freie Universität Berlin, Laboratory of Structural Biochemistry, 14195 Berlin, Germany; Helmholtz-Zentrum Berlin für Materialien und Energie, Macromolecular Crystallography, 12489 Berlin, Germany.
| |
Collapse
|
18
|
Distinct RNA-unwinding mechanisms of DEAD-box and DEAH-box RNA helicase proteins in remodeling structured RNAs and RNPs. Biochem Soc Trans 2017; 45:1313-1321. [PMID: 29150525 DOI: 10.1042/bst20170095] [Citation(s) in RCA: 57] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 10/16/2017] [Accepted: 10/23/2017] [Indexed: 01/03/2023]
Abstract
Structured RNAs and RNA-protein complexes (RNPs) fold through complex pathways that are replete with misfolded traps, and many RNAs and RNPs undergo extensive conformational changes during their functional cycles. These folding steps and conformational transitions are frequently promoted by RNA chaperone proteins, notably by superfamily 2 (SF2) RNA helicase proteins. The two largest families of SF2 helicases, DEAD-box and DEAH-box proteins, share evolutionarily conserved helicase cores, but unwind RNA helices through distinct mechanisms. Recent studies have advanced our understanding of how their distinct mechanisms enable DEAD-box proteins to disrupt RNA base pairs on the surfaces of structured RNAs and RNPs, while some DEAH-box proteins are adept at disrupting base pairs in the interior of RNPs. Proteins from these families use these mechanisms to chaperone folding and promote rearrangements of structured RNAs and RNPs, including the spliceosome, and may use related mechanisms to maintain cellular messenger RNAs in unfolded or partially unfolded conformations.
Collapse
|
19
|
De Novo Missense Mutations in DHX30 Impair Global Translation and Cause a Neurodevelopmental Disorder. Am J Hum Genet 2017; 101:716-724. [PMID: 29100085 DOI: 10.1016/j.ajhg.2017.09.014] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2017] [Accepted: 09/19/2017] [Indexed: 11/21/2022] Open
Abstract
DHX30 is a member of the family of DExH-box helicases, which use ATP hydrolysis to unwind RNA secondary structures. Here we identified six different de novo missense mutations in DHX30 in twelve unrelated individuals affected by global developmental delay (GDD), intellectual disability (ID), severe speech impairment and gait abnormalities. While four mutations are recurrent, two are unique with one affecting the codon of one recurrent mutation. All amino acid changes are located within highly conserved helicase motifs and were found to either impair ATPase activity or RNA recognition in different in vitro assays. Moreover, protein variants exhibit an increased propensity to trigger stress granule (SG) formation resulting in global translation inhibition. Thus, our findings highlight the prominent role of translation control in development and function of the central nervous system and also provide molecular insight into how DHX30 dysfunction might cause a neurodevelopmental disorder.
Collapse
|
20
|
Robert-Paganin J, Halladjian M, Blaud M, Lebaron S, Delbos L, Chardon F, Capeyrou R, Humbert O, Henry Y, Henras AK, Réty S, Leulliot N. Functional link between DEAH/RHA helicase Prp43 activation and ATP base binding. Nucleic Acids Res 2017; 45:1539-1552. [PMID: 28180308 PMCID: PMC5388414 DOI: 10.1093/nar/gkw1233] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Revised: 11/17/2016] [Accepted: 11/26/2016] [Indexed: 02/05/2023] Open
Abstract
The DEAH box helicase Prp43 is a bifunctional enzyme from the DEAH/RHA helicase family required both for the maturation of ribosomes and for lariat intron release during splicing. It interacts with G-patch domain containing proteins which activate the enzymatic activity of Prp43 in vitro by an unknown mechanism. In this work, we show that the activation by G-patch domains is linked to the unique nucleotide binding mode of this helicase family. The base of the ATP molecule is stacked between two residues, R159 of the RecA1 domain (R-motif) and F357 of the RecA2 domain (F-motif). Using Prp43 F357A mutants or pyrimidine nucleotides, we show that the lack of stacking of the nucleotide base to the F-motif decouples the NTPase and helicase activities of Prp43. In contrast the R159A mutant (R-motif) showed reduced ATPase and helicase activities. We show that the Prp43 R-motif mutant induces the same phenotype as the absence of the G-patch protein Gno1, strongly suggesting that the processing defects observed in the absence of Gno1 result from a failure to activate the Prp43 helicase. Overall we propose that the stacking between the R- and F-motifs and the nucleotide base is important for the activity and regulation of this helicase family.
Collapse
Affiliation(s)
- Julien Robert-Paganin
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Maral Halladjian
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Magali Blaud
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Simon Lebaron
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Lila Delbos
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Florian Chardon
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Régine Capeyrou
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Odile Humbert
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Yves Henry
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Anthony K Henras
- Laboratoire de Biologie Moléculaire Eucaryote, Centre de Biologie Intégrative, Université de Toulouse, CNRS, UPS, France
| | - Stéphane Réty
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| | - Nicolas Leulliot
- Laboratoire de Cristallographie et RMN Biologiques, UMR CNRS 8015, Université Paris Descartes, Sorbonne Paris Cité, Faculté de Pharmacie, Paris, France
| |
Collapse
|
21
|
Chen Z, Gui B, Zhang Y, Xie G, Li W, Liu S, Xu B, Wu C, He L, Yang J, Yi X, Yang X, Sun L, Liang J, Shang Y. Identification of a 35S U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP) complex intermediate in spliceosome assembly. J Biol Chem 2017; 292:18113-18128. [PMID: 28878014 DOI: 10.1074/jbc.m117.797357] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Revised: 08/28/2017] [Indexed: 11/06/2022] Open
Abstract
The de novo assembly and post-splicing reassembly of the U4/U6.U5 tri-snRNP remain to be investigated. We report here that ZIP, a protein containing a CCCH-type zinc finger and a G-patch domain, as characterized by us previously, regulates pre-mRNA splicing independent of RNA binding. We found that ZIP physically associates with the U4/U6.U5 tri-small nuclear ribonucleoprotein (tri-snRNP). Remarkably, the ZIP-containing tri-snRNP, which has a sedimentation coefficient of ∼35S, is a tri-snRNP that has not been described previously. We also found that the 35S tri-snRNP contains hPrp24, indicative of a state in which the U4/U6 di-snRNP is integrating with the U5 snRNP. We found that the 35S tri-snRNP is enriched in the Cajal body, indicating that it is an assembly intermediate during 25S tri-snRNP maturation. We showed that the 35S tri-snRNP also contains hPrp43, in which ATPase/RNA helicase activities are stimulated by ZIP. Our study identified, for the first time, a tri-snRNP intermediate, shedding new light on the de novo assembly and recycling of the U4/U6.U5 tri-snRNP.
Collapse
Affiliation(s)
- Zhe Chen
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bin Gui
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yu Zhang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Guojia Xie
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Wanjin Li
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Shumeng Liu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Bosen Xu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Chongyang Wu
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Lin He
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jianguo Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xia Yi
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Xiaohan Yang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Luyang Sun
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Jing Liang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yongfeng Shang
- From the Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China, .,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Tianjin Medical University, Tianjin 300070, China, and.,the Department of Biochemistry and Molecular Biology, School of Basic Medical Sciences, Capital Medical University, Beijing 100069, China
| |
Collapse
|
22
|
Fourmann JB, Tauchert MJ, Ficner R, Fabrizio P, Lührmann R. Regulation of Prp43-mediated disassembly of spliceosomes by its cofactors Ntr1 and Ntr2. Nucleic Acids Res 2017; 45:4068-4080. [PMID: 27923990 PMCID: PMC5397206 DOI: 10.1093/nar/gkw1225] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Accepted: 11/22/2016] [Indexed: 12/18/2022] Open
Abstract
The DEAH-box NTPase Prp43 disassembles spliceosomes in co-operation with the cofactors Ntr1/Spp382 and Ntr2, forming the NTR complex. How Prp43 is regulated by its cofactors to discard selectively only intron-lariat spliceosomes (ILS) and defective spliceosomes and to prevent disassembly of earlier and properly assembled/wild-type spliceosomes remains unclear. First, we show that Ntr1΄s G-patch motif (Ntr1GP) can be replaced by the GP motif of Pfa1/Sqs1, a Prp43΄s cofactor in ribosome biogenesis, demonstrating that the specific function of Ntr1GP is to activate Prp43 for spliceosome disassembly and not to guide Prp43 to its binding site in the spliceosome. Furthermore, we show that Ntr1΄s C-terminal domain (CTD) plays a safeguarding role by preventing Prp43 from disrupting wild-type spliceosomes other than the ILS. Ntr1 and Ntr2 can also discriminate between wild-type and defective spliceosomes. In both type of spliceosomes, Ntr1-CTD impedes Prp43-mediated disassembly while the Ntr1GP promotes disassembly. Intriguingly, Ntr2 plays a specific role in defective spliceosomes, likely by stabilizing Ntr1 and allowing Prp43 to enter a productive interaction with the GP motif of Ntr1. Our data indicate that Ntr1 and Ntr2 act as ‘doorkeepers’ and suggest that both cofactors inspect the RNP structure of spliceosomal complexes thereby targeting suboptimal spliceosomes for Prp43-mediated disassembly.
Collapse
Affiliation(s)
- Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - Marcel J Tauchert
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg August University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg August University of Göttingen, Justus-von-Liebig-Weg 11, Göttingen, Germany
| | - Patrizia Fabrizio
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Am Fassberg 11, Göttingen, Germany
| |
Collapse
|
23
|
|
24
|
He Y, Staley JP, Andersen GR, Nielsen KH. Structure of the DEAH/RHA ATPase Prp43p bound to RNA implicates a pair of hairpins and motif Va in translocation along RNA. RNA (NEW YORK, N.Y.) 2017; 23:1110-1124. [PMID: 28416566 PMCID: PMC5473145 DOI: 10.1261/rna.060954.117] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/30/2017] [Accepted: 04/10/2017] [Indexed: 06/07/2023]
Abstract
Three families of nucleic acid-dependent ATPases (DEAH/RHA, Ski2-like, and NS3/NPH-II), termed the DExH ATPases, are thought to execute myriad functions by processive, ATP-dependent, 3' to 5' translocation along single-stranded nucleic acid. While the mechanism of translocation of the viral NS3/NPH-II family has been studied extensively, it has not been clear if or how the principles that have emerged for this family extend to the other two families. Here we report the crystal structure of the yeast DEAH/RHA family ATPase Prp43p, which functions in splicing and ribosome biogenesis, in complex with poly-uracil and a nonhydrolyzable ATP analog. The structure reveals a conserved DEAH/RHA-specific variation of motif Ib within the RecA1 domain of the catalytic core, in which the motif elongates as a β-hairpin that bookends the 3' end of a central RNA stack, a function that in the viral and Ski-2 families is performed by an auxiliary domain. Supporting a fundamental role in translocation, mutations in this hairpin abolished helicase activity without affecting RNA binding or ATPase activity. While the structure reveals differences with viral ATPases in the RecA1 domain, our structure demonstrates striking similarities with viral ATPases in the RecA2 domain of the catalytic core, including both a prominent β-hairpin that bookends the 5' end of the RNA stack and a dynamic motif Va that is implicated in mediating translocation. Our crystal structure, genetic, and biochemical experiments, as well as comparisons with other DExH ATPases, support a generalized mechanism for the DExH class of helicases involving a pair of bookends that inchworm along RNA.
Collapse
Affiliation(s)
- Yangzi He
- Department of Molecular Biology and Genetics, Aarhus University, DK8000 Aarhus C, Denmark
| | - Jonathan P Staley
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637, USA
| | - Gregers Rom Andersen
- Department of Molecular Biology and Genetics, Aarhus University, DK8000 Aarhus C, Denmark
| | - Klaus H Nielsen
- Department of Molecular Genetics and Cell Biology, University of Chicago, Chicago, Illinois 60637, USA
| |
Collapse
|
25
|
Studying structure and function of spliceosomal helicases. Methods 2017; 125:63-69. [PMID: 28668587 DOI: 10.1016/j.ymeth.2017.06.028] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2017] [Revised: 06/21/2017] [Accepted: 06/24/2017] [Indexed: 12/27/2022] Open
Abstract
The splicing of eukaryotic precursor mRNAs requires the activity of at least three DEAD-box helicases, one Ski2-like helicase and four DEAH-box helicases. High resolution structures for five of these spliceosomal helicases were obtained by means of X-ray crystallography. Additional low resolution structural information could be derived from single particle cryo electron microscopy and small angle X-ray scattering. The functional characterization includes biochemical methods to measure the ATPase and helicase activities. This review gives an overview on the techniques used to gain insights in to the structure and function of spliceosomal helicases.
Collapse
|
26
|
Murakami K, Nakano K, Shimizu T, Ohto U. The crystal structure of human DEAH-box RNA helicase 15 reveals a domain organization of the mammalian DEAH/RHA family. Acta Crystallogr F Struct Biol Commun 2017; 73:347-355. [PMID: 28580923 PMCID: PMC5458392 DOI: 10.1107/s2053230x17007336] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 05/17/2017] [Indexed: 12/31/2022] Open
Abstract
DEAH-box RNA helicase 15 (DHX15) plays important roles in RNA metabolism, including in splicing and in ribosome biogenesis. In addition, mammalian DHX15 also mediates the innate immune sensing of viral RNA. However, structural information on this protein is not available, although the structure of the fungal orthologue of this protein, Prp43, has been elucidated. Here, the crystal structure of the ADP-bound form of human DHX15 is reported at a resolution of 2.0 Å. This is the first structure to be revealed of a member of the mammalian DEAH-box RNA helicase (DEAH/RHA) family in a nearly complete form, including the catalytic core consisting of the two N-terminal RecA domains and the C-terminal regulatory domains (CTD). The ADP-bound form of DHX15 displayed a compact structure, in which the RecA domains made extensive contacts with the CTD. Notably, a potential RNA-binding site was found on the surface of a RecA domain with positive electrostatic potential. Almost all structural features were conserved between the fungal Prp43 and the human DHX15, suggesting that they share a fundamentally common mechanism of action and providing a better understanding of the specific mammalian functions of DHX15.
Collapse
Affiliation(s)
- Karin Murakami
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenji Nakano
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Toshiyuki Shimizu
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Science and Technology Agency (JST), Saitama 332-0012, Japan
| | - Umeharu Ohto
- Graduate School of Pharmaceutical Sciences, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| |
Collapse
|
27
|
Tauchert MJ, Fourmann JB, Lührmann R, Ficner R. Structural insights into the mechanism of the DEAH-box RNA helicase Prp43. eLife 2017; 6. [PMID: 28092261 PMCID: PMC5262380 DOI: 10.7554/elife.21510] [Citation(s) in RCA: 60] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Accepted: 01/15/2017] [Indexed: 12/29/2022] Open
Abstract
The DEAH-box helicase Prp43 is a key player in pre-mRNA splicing as well as the maturation of rRNAs. The exact modus operandi of Prp43 and of all other spliceosomal DEAH-box RNA helicases is still elusive. Here, we report crystal structures of Prp43 complexes in different functional states and the analysis of structure-based mutants providing insights into the unwinding and loading mechanism of RNAs. The Prp43•ATP-analog•RNA complex shows the localization of the RNA inside a tunnel formed by the two RecA-like and C-terminal domains. In the ATP-bound state this tunnel can be transformed into a groove prone for RNA binding by large rearrangements of the C-terminal domains. Several conformational changes between the ATP- and ADP-bound states explain the coupling of ATP hydrolysis to RNA translocation, mainly mediated by a β-turn of the RecA1 domain containing the newly identified RF motif. This mechanism is clearly different to those of other RNA helicases. DOI:http://dx.doi.org/10.7554/eLife.21510.001
Collapse
Affiliation(s)
- Marcel J Tauchert
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| | - Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-University Göttingen, Göttingen, Germany
| |
Collapse
|
28
|
Fourmann JB, Dybkov O, Agafonov DE, Tauchert MJ, Urlaub H, Ficner R, Fabrizio P, Lührmann R. The target of the DEAH-box NTP triphosphatase Prp43 in Saccharomyces cerevisiae spliceosomes is the U2 snRNP-intron interaction. eLife 2016; 5. [PMID: 27115347 PMCID: PMC4866824 DOI: 10.7554/elife.15564] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/25/2016] [Indexed: 12/19/2022] Open
Abstract
The DEAH-box NTPase Prp43 and its cofactors Ntr1 and Ntr2 form the NTR complex and are required for disassembling intron-lariat spliceosomes (ILS) and defective earlier spliceosomes. However, the Prp43 binding site in the spliceosome and its target(s) are unknown. We show that Prp43 fused to Ntr1's G-patch motif (Prp43_Ntr1GP) is as efficient as the NTR in ILS disassembly, yielding identical dissociation products and recognizing its natural ILS target even in the absence of Ntr1’s C-terminal-domain (CTD) and Ntr2. Unlike the NTR, Prp43_Ntr1GP disassembles earlier spliceosomal complexes (A, B, Bact), indicating that Ntr2/Ntr1-CTD prevents NTR from disrupting properly assembled spliceosomes other than the ILS. The U2 snRNP-intron interaction is disrupted in all complexes by Prp43_Ntr1GP, and in the spliceosome contacts U2 proteins and the pre-mRNA, indicating that the U2 snRNP-intron interaction is Prp43’s major target. DOI:http://dx.doi.org/10.7554/eLife.15564.001
Collapse
Affiliation(s)
- Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Olexandr Dybkov
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Dmitry E Agafonov
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Marcel J Tauchert
- Department of Molecular Structure Biology, Institute for Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Bionalytics, Institute for Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany.,Bioanalytical Mass Spectrometry Group, Max Planck Institute for Biophysical Chemistry, Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structure Biology, Institute for Microbiology and Genetics, Georg August University of Göttingen, Göttingen, Germany
| | - Patrizia Fabrizio
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max-Planck-Institute for Biophysical Chemistry, Göttingen, Germany
| |
Collapse
|
29
|
Tauchert MJ, Fourmann JB, Christian H, Lührmann R, Ficner R. Structural and functional analysis of the RNA helicase Prp43 from the thermophilic eukaryote Chaetomium thermophilum. Acta Crystallogr F Struct Biol Commun 2016; 72:112-20. [PMID: 26841761 PMCID: PMC4741191 DOI: 10.1107/s2053230x15024498] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 12/20/2015] [Indexed: 02/03/2023] Open
Abstract
RNA helicases are indispensable for all organisms in each domain of life and have implications in numerous cellular processes. The DEAH-box RNA helicase Prp43 is involved in pre-mRNA splicing as well as rRNA maturation. Here, the crystal structure of Chaetomium thermophilum Prp43 at 2.9 Å resolution is revealed. Furthermore, it is demonstrated that Prp43 from C. thermophilum is capable of functionally replacing its orthologue from Saccharomyces cerevisiae in spliceosomal disassembly assays.
Collapse
Affiliation(s)
- Marcel J. Tauchert
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Jean-Baptiste Fourmann
- Department of Cellular Biochemistry, Max Planck Institute of Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Henning Christian
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| | - Reinhard Lührmann
- Department of Cellular Biochemistry, Max Planck Institute of Biophysical Chemistry, Am Fassberg 11, 37077 Göttingen, Germany
| | - Ralf Ficner
- Department of Molecular Structural Biology, Institute for Microbiology and Genetics, GZMB, Georg-August-Universität Göttingen, Justus-von-Liebig Weg 11, 37077 Göttingen, Germany
| |
Collapse
|
30
|
He Y, Andersen GR, Nielsen KH. The function and architecture of DEAH/RHA helicases. Biomol Concepts 2015; 2:315-26. [PMID: 25962039 DOI: 10.1515/bmc.2011.024] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2011] [Accepted: 05/24/2011] [Indexed: 12/11/2022] Open
Abstract
Helicases are ubiquitous enzymes that participate in every aspect of nucleic acid metabolism. The DEAH/RHA family of helicases are involved in a variety of cellular processes including transcriptional and translational regulation, pre-mRNA splicing, pre-rRNA processing, mRNA export and decay, in addition to the innate immune response. Recently, the first crystal structures of a DEAH/RHA helicase unveiled the unique structural features of this helicase family. These structures furthermore illuminate the molecular mechanism of these proteins and provide a framework for analysis of their interaction with nucleic acids, regulatory proteins and large macromolecular complexes.
Collapse
|
31
|
Liu YC, Cheng SC. Functional roles of DExD/H-box RNA helicases in Pre-mRNA splicing. J Biomed Sci 2015; 22:54. [PMID: 26173448 PMCID: PMC4503299 DOI: 10.1186/s12929-015-0161-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2015] [Accepted: 06/29/2015] [Indexed: 01/30/2023] Open
Abstract
Splicing of precursor mRNA takes place via two consecutive steps of transesterification catalyzed by a large ribonucleoprotein complex called the spliceosome. The spliceosome is assembled through ordered binding to the pre-mRNA of five small nuclear RNAs and numerous protein factors, and is disassembled after completion of the reaction to recycle all components. Throughout the splicing cycle, the spliceosome changes its structure, rearranging RNA-RNA, RNA-protein and protein-protein interactions, for positioning and repositioning of splice sites. DExD/H-box RNA helicases play important roles in mediating structural changes of the spliceosome by unwinding of RNA duplexes or disrupting RNA-protein interactions. DExD/H-box proteins are also implicated in the fidelity control of the splicing process at various steps. This review summarizes the functional roles of DExD/H-box proteins in pre-mRNA splicing according to studies conducted mostly in yeast and will discuss the concept of the complicated splicing reaction based on recent findings.
Collapse
Affiliation(s)
- Yen-Chi Liu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, 115, Republic of China.
| | - Soo-Chen Cheng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, 115, Republic of China.
| |
Collapse
|
32
|
Regulation of DEAH/RHA helicases by G-patch proteins. BIOMED RESEARCH INTERNATIONAL 2015; 2015:931857. [PMID: 25692149 PMCID: PMC4322301 DOI: 10.1155/2015/931857] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 10/19/2014] [Accepted: 10/24/2014] [Indexed: 11/20/2022]
Abstract
RNA helicases from the DEAH/RHA family are present in all the processes of RNA metabolism. The function of two helicases from this family, Prp2 and Prp43, is regulated by protein partners containing a G-patch domain. The G-patch is a glycine-rich domain discovered by sequence alignment, involved in protein-protein and protein-nucleic acid interaction. Although it has been shown to stimulate the helicase's enzymatic activities, the precise role of the G-patch domain remains unclear. The role of G-patch proteins in the regulation of Prp43 activity has been studied in the two biological processes in which it is involved: splicing and ribosome biogenesis. Depending on the pathway, the activity of Prp43 is modulated by different G-patch proteins. A particular feature of the structure of DEAH/RHA helicases revealed by the Prp43 structure is the OB-fold domain in C-terminal part. The OB-fold has been shown to be a platform responsible for the interaction with G-patch proteins and RNA. Though there is still no structural data on the G-patch domain, in the current model, the interaction between the helicase, the G-patch protein, and RNA leads to a cooperative binding of RNA and conformational changes of the helicase.
Collapse
|
33
|
Abstract
Superfamily 2 helicase proteins are ubiquitous in RNA biology and have an extraordinarily broad set of functional roles. Central among these roles are the promotion of rearrangements of structured RNAs and the remodeling of ribonucleoprotein complexes (RNPs), allowing formation of native RNA structure or progression through a functional cycle of structures. Although all superfamily 2 helicases share a conserved helicase core, they are divided evolutionarily into several families, and it is principally proteins from three families, the DEAD-box, DEAH/RHA, and Ski2-like families, that function to manipulate structured RNAs and RNPs. Strikingly, there are emerging differences in the mechanisms of these proteins, both between families and within the largest family (DEAD-box), and these differences appear to be tuned to their RNA or RNP substrates and their specific roles. This review outlines basic mechanistic features of the three families and surveys individual proteins and the current understanding of their biological substrates and mechanisms.
Collapse
Affiliation(s)
- Inga Jarmoskaite
- Department of Molecular Biosciences and the Institute for Cellular and Molecular Biology, University of Texas, Austin, Texas 78712; ,
| | | |
Collapse
|
34
|
Guo M, Vidhyasagar V, Ding H, Wu Y. Insight into the roles of helicase motif Ia by characterizing Fanconi anemia group J protein (FANCJ) patient mutations. J Biol Chem 2014; 289:10551-10565. [PMID: 24573678 DOI: 10.1074/jbc.m113.538892] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Helicases are molecular motors that couple the energy of ATP hydrolysis to the unwinding and remodeling of structured DNA or RNA, which is coordinated by conserved helicase motifs. FANCJ is a DNA helicase that is genetically linked to Fanconi anemia, breast cancer, and ovarian cancer. Here, we characterized two Fanconi anemia patient mutations, R251C and Q255H, that are localized in helicase motif Ia. Our genetic complementation analysis revealed that both the R251C and Q255H alleles failed to rescue cisplatin sensitivity of a FANCJ null cell line as detected by cell survival or γ-H2AX foci formation. Furthermore, our biochemical assays demonstrated that both purified recombinant proteins abolished DNA helicase activity and failed to disrupt the DNA-protein complex. Intriguingly, R251C impaired DNA binding ability to single-strand DNA and double-strand DNA, whereas Q255H retained higher binding activity to these DNA substrates compared with wild-type FANCJ protein. Consequently, R251C abolished its DNA-dependent ATP hydrolysis activity, whereas Q255H retained normal ATPase activity. Physically, R251C had reduced ATP binding ability, whereas Q255H had normal ATP binding ability and could translocate on single-strand DNA. Although both proteins were recruited to damage sites in our laser-activated confocal assays, they lost their DNA repair function, which explains why they exerted a domain negative effect when expressed in a wild-type background. Taken together, our work not only reveals the structural function of helicase motif Ia but also provides the molecular pathology of FANCJ in related diseases.
Collapse
Affiliation(s)
- Manhong Guo
- Department of Biochemistry, University of Saskatchewan, Health Sciences Building, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Venkatasubramanian Vidhyasagar
- Department of Biochemistry, University of Saskatchewan, Health Sciences Building, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Hao Ding
- Department of Biochemistry, University of Saskatchewan, Health Sciences Building, Saskatoon, Saskatchewan, S7N 5E5, Canada
| | - Yuliang Wu
- Department of Biochemistry, University of Saskatchewan, Health Sciences Building, Saskatoon, Saskatchewan, S7N 5E5, Canada.
| |
Collapse
|
35
|
Zhang ZM, Yang F, Zhang J, Tang Q, Li J, Gu J, Zhou J, Xu YZ. Crystal structure of Prp5p reveals interdomain interactions that impact spliceosome assembly. Cell Rep 2013; 5:1269-78. [PMID: 24290758 DOI: 10.1016/j.celrep.2013.10.047] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2013] [Revised: 09/30/2013] [Accepted: 10/29/2013] [Indexed: 01/13/2023] Open
Abstract
The DEAD-box adenosine triphosphatase (ATPase) Prp5p facilitates U2 small nuclear ribonucleoprotein particle (snRNP) binding to the intron branch site region during spliceosome assembly. We present crystal structures of S. cerevisiae Prp5p alone and in complex with ADP at 2.12 Å and 1.95 Å resolution. The three-dimensional packing of Prp5p subdomains differs strikingly from that so far observed in other DEAD-box proteins: two RecA-like subdomains adopt an "open state" conformation stabilized by extensive interactions involving sequences that flank the two subdomains. This conformation is distinct from that required for ATP hydrolysis. Consistent with this, Prp5p mutations that destabilize interdomain interactions exhibited increased ATPase activity in vitro and inhibited splicing of suboptimal branch site substrates in vivo, whereas restoration of interdomain interactions reversed these effects. We conclude that the Prp5p open state conformation is biologically relevant and that disruption of the interdomain interaction facilitates a large-scale conformational change of Prp5p during U2 snRNP-branch site recognition.
Collapse
Affiliation(s)
- Zhi-Min Zhang
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Fei Yang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jinru Zhang
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Qing Tang
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jie Li
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jing Gu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China
| | - Jiahai Zhou
- State Key Laboratory of Bio-organic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China.
| | - Yong-Zhen Xu
- Key Laboratory of Insect Developmental and Evolutionary Biology, Institute of Plant Physiology and Ecology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200032, China.
| |
Collapse
|
36
|
Christian H, Hofele RV, Urlaub H, Ficner R. Insights into the activation of the helicase Prp43 by biochemical studies and structural mass spectrometry. Nucleic Acids Res 2013; 42:1162-79. [PMID: 24165877 PMCID: PMC3902948 DOI: 10.1093/nar/gkt985] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023] Open
Abstract
Splicing of precursor messenger RNA is a hallmark of eukaryotic cells, which is carried out by the spliceosome, a multi-megadalton ribonucleoprotein machinery. The splicing reaction removes non-coding regions (introns) and ligates coding regions (exons). The spliceosome is a highly dynamic ribonucleoprotein complex that undergoes dramatic structural changes during its assembly, the catalysis and its disassembly. The transitions between the different steps during the splicing cycle are promoted by eight conserved DExD/H box ATPases. The DEAH-box protein Prp43 is responsible for the disassembly of the intron-lariat spliceosome and its helicase activity is activated by the G-patch protein Ntr1. Here, we investigate the activation of Prp43 by Ntr1 in the presence and absence of RNA substrate by functional assays and structural proteomics. Residues 51–110 of Ntr1 were identified to be the minimal fragment that induces full activation. We found protein–protein cross-links that indicate that Prp43 interacts with the G-patch motif of Ntr1 through its C-terminal domains. Additionally, we report on functionally important RNA binding residues in both proteins and propose a model for the activation of the helicase.
Collapse
Affiliation(s)
- Henning Christian
- Department for Molecular Structural Biology, Institute for Microbiology and Genetics, Georg-August-University Göttingen, D-37077 Göttingen, Germany, Bioanalytical Mass Spectrometry Group, Max-Planck-Institute of Biophysical Chemistry, D-37077 Göttingen, Germany and Bioanalytics, Department of Clinical Chemistry, University Medical Center Göttingen, D-37075 Göttingen, Germany
| | | | | | | |
Collapse
|
37
|
Schellenberg MJ, Wu T, Ritchie DB, Fica S, Staley JP, Atta KA, LaPointe P, MacMillan AM. A conformational switch in PRP8 mediates metal ion coordination that promotes pre-mRNA exon ligation. Nat Struct Mol Biol 2013; 20:728-34. [PMID: 23686287 PMCID: PMC3703396 DOI: 10.1038/nsmb.2556] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2013] [Accepted: 03/12/2013] [Indexed: 01/05/2023]
Abstract
Splicing of pre-mRNAs in eukaryotes is catalyzed by the spliceosome a large RNA–protein metalloenzyme. The catalytic center of the spliceosome involves a structure comprised of the U2 and U6 snRNAs and includes a metal bound by U6 snRNA. The precise architecture of the splicesome active site however, including the question of whether it includes protein components, remains unresolved. A wealth of evidence places the protein PRP8 at the heart of the spliceosome through assembly and catalysis. Here we provide evidence that the RNase H domain of PRP8 undergoes a conformational switch between the two steps of splicing rationalizing yeast prp8 alleles promoting either the first or second step. We also show that this switch unmasks a metal-binding site involved in the second step. Together these data establish that PRP8 is a metalloprotein that promotes exon ligation within the spliceosome.
Collapse
|
38
|
Zhang L, Li X, Zhao R. Structural analyses of the pre-mRNA splicing machinery. Protein Sci 2013; 22:677-92. [PMID: 23592432 DOI: 10.1002/pro.2266] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/03/2013] [Accepted: 04/08/2013] [Indexed: 01/03/2023]
Abstract
Pre-mRNA splicing is a critical event in the gene expression pathway of all eukaryotes. The splicing reaction is catalyzed by the spliceosome, a huge protein-RNA complex that contains five snRNAs and hundreds of different protein factors. Understanding the structure of this large molecular machinery is critical for understanding its function. Although the highly dynamic nature of the spliceosome, in both composition and conformation, posed daunting challenges to structural studies, there has been significant recent progress on structural analyses of the splicing machinery, using electron microscopy, crystallography, and nuclear magnetic resonance. This review discusses key recent findings in the structural analyses of the spliceosome and its components and how these findings advance our understanding of the function of the splicing machinery.
Collapse
Affiliation(s)
- Lingdi Zhang
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, Colorado 80045, USA
| | | | | |
Collapse
|
39
|
A weak spliceosome-binding domain of Yju2 functions in the first step and bypasses Prp16 in the second step of splicing. Mol Cell Biol 2013; 33:1746-55. [PMID: 23438600 DOI: 10.1128/mcb.00035-13] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Yju2 is an essential splicing factor required for the first catalytic step after the action of Prp2. We dissected the structure of Yju2 and found that the amino (Yju2-N) and carboxyl (Yju2-C) halves of the protein can be separated and reconstituted for Yju2 function both in vivo and in vitro. Yju2-N has a weak affinity for the spliceosome but functions in promoting the first reaction, with the second reaction being severely impeded. The association of Yju2-N with the spliceosome is stabilized by the presence of Yju2-C at both the precatalytic and postcatalytic stages. Strikingly, Yju2-N supported a low level of the second reaction even in the absence of Prp16. Prp16 is known to mediate destabilization of Yju2 and Cwc25 after the first reaction to allow progression of the second reaction. We propose that in the absence of the C domain, Yju2-N is not stably associated with the spliceosome after lariat formation, and thus bypasses the need for Prp16. We also showed, by UV cross-linking, that Yju2 directly contacts U2 snRNA primarily in the helix II region both pre- and postcatalytically and in the branch-binding region only at the precatalytic stage, suggesting a possible role for Yju2 in positioning the branch point during the first reaction.
Collapse
|
40
|
Rodríguez-Galán O, García-Gómez JJ, de la Cruz J. Yeast and human RNA helicases involved in ribosome biogenesis: current status and perspectives. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2013; 1829:775-90. [PMID: 23357782 DOI: 10.1016/j.bbagrm.2013.01.007] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/02/2012] [Revised: 01/15/2013] [Accepted: 01/16/2013] [Indexed: 11/17/2022]
Abstract
Ribosome biogenesis is a fundamental process that is conserved in eukaryotes. Although spectacular progress has been made in understanding mammalian ribosome synthesis in recent years, by far, this process has still been best characterised in the yeast Saccharomyces cerevisiae. In yeast, besides the rRNAs, the ribosomal proteins and the 75 small nucleolar RNAs, more than 250 non-ribosomal proteins, generally referred to as trans-acting factors, are involved in ribosome biogenesis. These factors include nucleases, RNA modifying enzymes, ATPases, GTPases, kinases and RNA helicases. Altogether, they likely confer speed, accuracy and directionality to the ribosome synthesis process, however, the precise functions for most of them are still largely unknown. This review summarises our current knowledge on eukaryotic RNA helicases involved in ribosome biogenesis, particularly focusing on the most recent advances with respect to the molecular roles of these enzymes and their co-factors in yeast and human cells. This article is part of a Special Issue entitled: The Biology of RNA helicases-Modulation for life.
Collapse
|
41
|
Abstract
RNA splicing is one of the fundamental processes in gene expression in eukaryotes. Splicing of pre-mRNA is catalysed by a large ribonucleoprotein complex called the spliceosome, which consists of five small nuclear RNAs and numerous protein factors. The spliceosome is a highly dynamic structure, assembled by sequential binding and release of the small nuclear RNAs and protein factors. DExD/H-box RNA helicases are required to mediate structural changes in the spliceosome at various steps in the assembly pathway and have also been implicated in the fidelity control of the splicing reaction. Other proteins also play key roles in mediating the progression of the spliceosome pathway. In this review, we discuss the functional roles of the protein factors involved in the spliceosome pathway primarily from studies in the yeast system.
Collapse
|
42
|
Putnam A, Jankowsky E. Analysis of duplex unwinding by RNA helicases using stopped-flow fluorescence spectroscopy. Methods Enzymol 2012; 511:1-27. [PMID: 22713313 DOI: 10.1016/b978-0-12-396546-2.00001-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/11/2023]
Abstract
The characterization of unwinding reactions by RNA helicases often requires the determination of rate constants that are too fast to be measured by traditional, manual gel-based methods. Stopped-flow fluorescence measurements allow access to fast unwinding rate constants. In this chapter, we outline strategies and experimental considerations for the design of stopped-flow fluorescence experiments to monitor duplex unwinding by RNA helicases, with focus on DEAD-box helicases. We discuss advantages, disadvantages, and technical considerations for stopped-flow approaches, as well as substrate design. In addition, we list protocols and explain functional information obtained with these experiments.
Collapse
Affiliation(s)
- Andrea Putnam
- Department of Biochemistry, Center for RNA Molecular Biology, School of Medicine, Case Western Reserve University, Cleveland, Ohio, USA
| | | |
Collapse
|
43
|
Roles of individual domains in the function of DHX29, an essential factor required for translation of structured mammalian mRNAs. Proc Natl Acad Sci U S A 2012; 109:E3150-9. [PMID: 23047696 DOI: 10.1073/pnas.1208014109] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
On most eukaryotic mRNAs, initiation codon selection involves base-by-base inspection of 5' UTRs by scanning ribosomal complexes. Although the eukaryotic initiation factors 4A/4B/4G can mediate scanning through medium-stability hairpins, scanning through more stable structures additionally requires DHX29, a member of the superfamily 2 DEAH/RNA helicase A (RHA) helicase family that binds to 40S subunits and possesses 40S-stimulated nucleoside triphosphatase (NTPase) activity. Here, sequence alignment and structural modeling indicated that DHX29 comprises a unique 534-aa-long N-terminal region (NTR), central catalytic RecA1/RecA2 domains containing a large insert in the RecA2 domain, and the C-terminal part, which includes winged-helix, ratchet, and oligonucleotide/oligosaccharide-binding (OB) domains that are characteristic of DEAH/RHA helicases. Functional characterization revealed that specific ribosomal targeting is required for DHX29's activity in initiation and is determined by elements that map to the NTR and to the N-terminal half of the winged-helix domain. The ribosome-binding determinant located in the NTR was identified as a putative double-stranded RNA-binding domain. Mutational analyses of RecA1/RecA2 domains confirmed the essential role of NTP hydrolysis for DHX29's function in initiation and validated the significance of a β-hairpin protruding from RecA2. The large RecA2 insert played an autoinhibitory role in suppressing DHX29's intrinsic NTPase activity but was not essential for its 40S-stimulated NTPase activity and function in initiation. Deletion of the OB domain also increased DHX29's basal NTPase activity, but more importantly, abrogated the responsiveness of the NTPase activity to stimulation, which abolished DHX29's function in initiation. This finding suggests that the OB domain, which is specific for DEAH/RHA helicases, plays an important role in their NTPase cycle.
Collapse
|
44
|
Horowitz DS. The mechanism of the second step of pre-mRNA splicing. WILEY INTERDISCIPLINARY REVIEWS-RNA 2011; 3:331-50. [PMID: 22012849 DOI: 10.1002/wrna.112] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The molecular mechanisms of the second step of pre-mRNA splicing in yeast and higher eukaryotes are reviewed. The important elements in the pre-mRNA, the participating proteins, and the proposed secondary structures and roles of the snRNAs are described. The sequence of events in the second step is presented, focusing on the actions of the proteins in setting up and facilitating the second reaction. Mechanisms for avoiding errors in splicing are discussed.
Collapse
Affiliation(s)
- David S Horowitz
- Department of Biochemistry and Molecular Biology, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| |
Collapse
|
45
|
Tuteja R. Helicases involved in splicing from malaria parasite Plasmodium falciparum. Parasitol Int 2011; 60:335-40. [PMID: 21996352 DOI: 10.1016/j.parint.2011.09.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2011] [Revised: 09/14/2011] [Accepted: 09/18/2011] [Indexed: 02/06/2023]
Abstract
An interesting element of eukaryotic genomes is the large quantity of non-coding intervening sequences commonly known as introns, which regularly interrupt functional genes and therefore must be removed prior to the use of genetic information by the cell. After splicing, the mature RNA is exported from the nucleus to the cytoplasm. Any error in the process of recognition and removal of introns, or splicing, would lead to change in genetic message and thus has potentially catastrophic consequences. Thus splicing is a highly complex essential step in eukaryotic gene expression. It takes place in spliceosome, which is a dynamic RNA-protein complex made of snRNPs and non-snRNP proteins. The splicing process consists of following sequential steps: spliceosome formation, the first transesterification and second transesterification reactions, release of the mature mRNA and recycling of the snRNPs. The spliceosomal components produce a complex network of RNA-RNA, RNA-protein and protein-protein interactions and spliceosome experience remodeling during each splicing cycle. Helicases are essentially required at almost each step for resolution of RNA-RNA and/or RNA-protein interactions. RNA helicases share a highly conserved helicase domain which includes the motif DExD/H in the single letter amino acid code. This article will focus on members of the DExD/H-box proteins involved specially in splicing in the malaria parasite Plasmodium falciparum.
Collapse
Affiliation(s)
- Renu Tuteja
- International Centre for Genetic Engineering and Biotechnology, New Delhi, India.
| |
Collapse
|
46
|
Charette JM, Baserga SJ. The DEAD-box RNA helicase-like Utp25 is an SSU processome component. RNA (NEW YORK, N.Y.) 2010; 16:2156-69. [PMID: 20884785 PMCID: PMC2957055 DOI: 10.1261/rna.2359810] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The SSU processome is a large ribonucleoprotein complex consisting of the U3 snoRNA and at least 43 proteins. A database search, initiated in an effort to discover additional SSU processome components, identified the uncharacterized, conserved and essential yeast nucleolar protein YIL091C/UTP25 as one such candidate. The C-terminal DUF1253 motif, a domain of unknown function, displays limited sequence similarity to DEAD-box RNA helicases. In the absence of the conserved DEAD-box sequence, motif Ia is the only clearly identifiable helicase element. Since the yeast homolog is nucleolar and interacts with components of the SSU processome, we examined its role in pre-rRNA processing. Genetic depletion of Utp25 resulted in slowed growth. Northern analysis of pre-rRNA revealed an 18S rRNA maturation defect at sites A₀, A₁, and A₂. Coimmunoprecipitation confirmed association with U3 snoRNA and with Mpp10, and with components of the t-Utp/UtpA, UtpB, and U3 snoRNP subcomplexes. Mutation of the conserved motif Ia residues resulted in no discernable temperature-sensitive or cold-sensitive growth defects, implying that this motif is dispensable for Utp25 function. A yeast two-hybrid screen of Utp25 against other SSU processome components revealed several interacting proteins, including Mpp10, Utp3, and Utp21, thereby identifying the first interactions among the different subcomplexes of the SSU processome. Furthermore, the DUF1253 domain is required and sufficient for the interaction of Utp25 with Utp3. Thus, Utp25 is a novel SSU processome component that, along with Utp3, forms the first identified interactions among the different SSU processome subcomplexes.
Collapse
Affiliation(s)
- J Michael Charette
- Department of Molecular Biophysics & Biochemistry, Yale University School of Medicine, New Haven, Connecticut 06520, USA
| | | |
Collapse
|
47
|
Prp43p contains a processive helicase structural architecture with a specific regulatory domain. EMBO J 2010; 29:2194-204. [PMID: 20512115 DOI: 10.1038/emboj.2010.102] [Citation(s) in RCA: 112] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Accepted: 05/03/2010] [Indexed: 01/21/2023] Open
Abstract
The DEAH/RNA helicase A (RHA) helicase family comprises proteins involved in splicing, ribosome biogenesis and transcription regulation. We report the structure of yeast Prp43p, a DEAH/RHA helicase remarkable in that it functions in both splicing and ribosome biogenesis. Prp43p displays a novel structural architecture with an unforeseen homology with the Ski2-like Hel308 DNA helicase. Together with the presence of a beta-hairpin in the second RecA-like domain, Prp43p contains all the structural elements of a processive helicase. Moreover, our structure reveals that the C-terminal domain contains an oligonucleotide/oligosaccharide-binding (OB)-fold placed at the entrance of the putative nucleic acid cavity. Deletion or mutations of this domain decrease the affinity of Prp43p for RNA and severely reduce Prp43p ATPase activity in the presence of RNA. We also show that this domain constitutes the binding site for the G-patch-containing domain of Pfa1p. We propose that the C-terminal domain, specific to DEAH/RHA helicases, is a central player in the regulation of helicase activity by binding both RNA and G-patch domain proteins.
Collapse
|
48
|
Lattmann S, Giri B, Vaughn JP, Akman SA, Nagamine Y. Role of the amino terminal RHAU-specific motif in the recognition and resolution of guanine quadruplex-RNA by the DEAH-box RNA helicase RHAU. Nucleic Acids Res 2010; 38:6219-33. [PMID: 20472641 PMCID: PMC2952847 DOI: 10.1093/nar/gkq372] [Citation(s) in RCA: 100] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
Under physiological conditions, guanine-rich sequences of DNA and RNA can adopt stable and atypical four-stranded helical structures called G-quadruplexes (G4). Such G4 structures have been shown to occur in vivo and to play a role in various processes such as transcription, translation and telomere maintenance. Owing to their high-thermodynamic stability, resolution of G4 structures in vivo requires specialized enzymes. RHAU is a human RNA helicase of the DEAH-box family that exhibits a unique ATP-dependent G4-resolvase activity with a high affinity and specificity for its substrate in vitro. How RHAU recognizes G4-RNAs has not yet been established. Here, we show that the amino-terminal region of RHAU is essential for RHAU to bind G4 structures and further identify within this region the evolutionary conserved RSM (RHAU-specific motif) domain as a major affinity and specificity determinant. G4-resolvase activity and strict RSM dependency are also observed with CG9323, the Drosophila orthologue of RHAU, in the amino terminal region of which the RSM is the only conserved motif. Thus, these results reveal a novel motif in RHAU protein that plays an important role in recognizing and resolving G4-RNA structures, properties unique to RHAU among many known RNA helicases.
Collapse
Affiliation(s)
- Simon Lattmann
- Friedrich Miescher Institute for Biomedical Research, Novartis Research Foundation, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | | | | | | | | |
Collapse
|
49
|
Fairman-Williams ME, Guenther UP, Jankowsky E. SF1 and SF2 helicases: family matters. Curr Opin Struct Biol 2010; 20:313-24. [PMID: 20456941 DOI: 10.1016/j.sbi.2010.03.011] [Citation(s) in RCA: 662] [Impact Index Per Article: 47.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2010] [Accepted: 03/29/2010] [Indexed: 12/25/2022]
Abstract
Helicases of the superfamily (SF) 1 and 2 are involved in virtually all aspects of RNA and DNA metabolism. SF1 and SF2 helicases share a catalytic core with high structural similarity, but different enzymes even within each SF perform a wide spectrum of distinct functions on diverse substrates. To rationalize similarities and differences between these helicases, we outline a classification based on protein families that are characterized by typical sequence, structural, and mechanistic features. This classification complements and extends existing SF1 and SF2 helicase categorizations and highlights major structural and functional themes for these proteins. We discuss recent data in the context of this unifying view of SF1 and SF2 helicases.
Collapse
Affiliation(s)
- Margaret E Fairman-Williams
- Center for RNA Molecular Biology & Department of Biochemistry, School of Medicine, Case Western Reserve University, Cleveland, OH 44106, USA
| | | | | |
Collapse
|
50
|
Structural basis for the function of DEAH helicases. EMBO Rep 2010; 11:180-6. [PMID: 20168331 DOI: 10.1038/embor.2010.11] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Revised: 12/11/2009] [Accepted: 01/14/2010] [Indexed: 11/09/2022] Open
Abstract
DEAH helicases participate in pre-messenger RNA splicing and ribosome biogenesis. The structure of yeast Prp43p-ADP reveals the homology of DEAH helicases to DNA helicases and the presence of an oligonucleotide-binding motif. A beta-hairpin from the second RecA domain is wedged between two carboxy-terminal domains and blocks access to the occluded RNA binding site formed by the RecA domains and a C-terminal domain. ATP binding and hydrolysis are likely to induce conformational changes in the hairpin that are important for RNA unwinding or ribonucleoprotein remodelling. The structure of Prp43p provides the framework for functional and genetic analysis of all DEAH helicases.
Collapse
|