1
|
Tafoya S, Bustamante C. Molecular switch-like regulation in motor proteins. Philos Trans R Soc Lond B Biol Sci 2019; 373:rstb.2017.0181. [PMID: 29735735 DOI: 10.1098/rstb.2017.0181] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/22/2017] [Indexed: 11/12/2022] Open
Abstract
Motor proteins are powered by nucleotide hydrolysis and exert mechanical work to carry out many fundamental biological tasks. To ensure their correct and efficient performance, the motors' activities are allosterically regulated by additional factors that enhance or suppress their NTPase activity. Here, we review two highly conserved mechanisms of ATP hydrolysis activation and repression operating in motor proteins-the glutamate switch and the arginine finger-and their associated regulatory factors. We examine the implications of these regulatory mechanisms in proteins that are formed by multiple ATPase subunits. We argue that the regulatory mechanisms employed by motor proteins display features similar to those described in small GTPases, which require external regulatory elements, such as dissociation inhibitors, exchange factors and activating proteins, to switch the protein's function 'on' and 'off'. Likewise, similar regulatory roles are taken on by the motor's substrate, additional binding factors, and even adjacent subunits in multimeric complexes. However, in motor proteins, more than one regulatory factor and the two mechanisms described here often underlie the machine's operation. Furthermore, ATPase regulation takes place throughout the motor's cycle, which enables a more complex function than the binary 'active' and 'inactive' states.This article is part of a discussion meeting issue 'Allostery and molecular machines'.
Collapse
Affiliation(s)
- Sara Tafoya
- Jason L. Choy Laboratory of Single Molecule Biophysics and Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA
| | - Carlos Bustamante
- Jason L. Choy Laboratory of Single Molecule Biophysics and Biophysics Graduate Group, University of California, Berkeley, Berkeley, CA 94720, USA .,Departments of Molecular and Cell Biology, Physics and Chemistry, University of California, Berkeley, Berkeley, CA 94720, USA.,Howard Hughes Medical Institute, California Institute for Quantitative Biosciences and Kavli Energy Nanoscience Institute, University of California, Berkeley, Berkeley, CA 94720, USA
| |
Collapse
|
2
|
The Ubiquitin Ligase Itch and Ubiquitination Regulate BFRF1-Mediated Nuclear Envelope Modification for Epstein-Barr Virus Maturation. J Virol 2016; 90:8994-9007. [PMID: 27466427 DOI: 10.1128/jvi.01235-16] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 07/19/2016] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The cellular endosomal sorting complex required for transport (ESCRT) was recently found to mediate important morphogenesis processes at the nuclear envelope (NE). We previously showed that the Epstein-Barr virus (EBV) BFRF1 protein recruits the ESCRT-associated protein Alix to modulate NE structure and promote EBV nuclear egress. Here, we uncover new cellular factors and mechanisms involved in this process. BFRF1-induced NE vesicles are similar to those observed following EBV reactivation. BFRF1 is ubiquitinated, and elimination of possible ubiquitination by either lysine mutations or fusion of a deubiquitinase hampers NE-derived vesicle formation and virus maturation. While it interacts with multiple Nedd4-like ubiquitin ligases, BFRF1 preferentially binds Itch ligase. We show that Itch associates with Alix and BFRF1 and is required for BFRF1-induced NE vesicle formation. Our data demonstrate that Itch, ubiquitin, and Alix control the BFRF1-mediated modulation of the NE and EBV maturation, uncovering novel regulatory mechanisms of nuclear egress of viral nucleocapsids. IMPORTANCE The nuclear envelope (NE) of eukaryotic cells not only serves as a transverse scaffold for cellular processes, but also as a natural barrier for most DNA viruses that assemble their nucleocapsids in the nucleus. Previously, we showed that the cellular endosomal sorting complex required for transport (ESCRT) machinery is required for the nuclear egress of EBV. Here, we further report the molecular interplay among viral BFRF1, the ESCRT adaptor Alix, and the ubiquitin ligase Itch. We found that BFRF1-induced NE vesicles are similar to those observed following EBV reactivation. The lysine residues and the ubiquitination of BFRF1 regulate the formation of BFRF1-induced NE-derived vesicles and EBV maturation. During the process, a ubiquitin ligase, Itch, preferably associates with BFRF1 and is required for BFRF1-induced NE vesicle formation. Therefore, our data indicate that Itch, ubiquitin, and Alix control the BFRF1-mediated modulation of the NE, suggesting novel regulatory mechanisms for ESCRT-mediated NE modulation.
Collapse
|
3
|
Hagen C, Dent KC, Zeev-Ben-Mordehai T, Grange M, Bosse JB, Whittle C, Klupp BG, Siebert CA, Vasishtan D, Bäuerlein FJB, Cheleski J, Werner S, Guttmann P, Rehbein S, Henzler K, Demmerle J, Adler B, Koszinowski U, Schermelleh L, Schneider G, Enquist LW, Plitzko JM, Mettenleiter TC, Grünewald K. Structural Basis of Vesicle Formation at the Inner Nuclear Membrane. Cell 2016; 163:1692-701. [PMID: 26687357 PMCID: PMC4701712 DOI: 10.1016/j.cell.2015.11.029] [Citation(s) in RCA: 155] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 09/11/2015] [Accepted: 11/06/2015] [Indexed: 12/22/2022]
Abstract
Vesicular nucleo-cytoplasmic transport is becoming recognized as a general cellular mechanism for translocation of large cargoes across the nuclear envelope. Cargo is recruited, enveloped at the inner nuclear membrane (INM), and delivered by membrane fusion at the outer nuclear membrane. To understand the structural underpinning for this trafficking, we investigated nuclear egress of progeny herpesvirus capsids where capsid envelopment is mediated by two viral proteins, forming the nuclear egress complex (NEC). Using a multi-modal imaging approach, we visualized the NEC in situ forming coated vesicles of defined size. Cellular electron cryo-tomography revealed a protein layer showing two distinct hexagonal lattices at its membrane-proximal and membrane-distant faces, respectively. NEC coat architecture was determined by combining this information with integrative modeling using small-angle X-ray scattering data. The molecular arrangement of the NEC establishes the basic mechanism for budding and scission of tailored vesicles at the INM. Multimodal imaging reveals mechanism of vesicle formation at inner nuclear membrane Nucleo-cytoplasmic cargo vesicle coat in situ comprises two distinct lattices Lattices are formed by hexameric building blocks made of the nuclear egress complex Induction of membrane curvature based solely on heterodimeric interactions
Collapse
Affiliation(s)
- Christoph Hagen
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Kyle C Dent
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK; Diamond Light Source Ltd., Harwell Science and Innovation Campus, Didcot OX11 0DE, UK
| | - Tzviya Zeev-Ben-Mordehai
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Michael Grange
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Jens B Bosse
- Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Cathy Whittle
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Barbara G Klupp
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany
| | - C Alistair Siebert
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Daven Vasishtan
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Felix J B Bäuerlein
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Juliana Cheleski
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK
| | - Stephan Werner
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Peter Guttmann
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Stefan Rehbein
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Katja Henzler
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Justin Demmerle
- Micron Oxford, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Barbara Adler
- Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität München, Pettenkoferstr. 9a, 80336 Munich, Germany
| | - Ulrich Koszinowski
- Max von Pettenkofer-Institut, Ludwig-Maximilians-Universität München, Pettenkoferstr. 9a, 80336 Munich, Germany
| | - Lothar Schermelleh
- Micron Oxford, Department of Biochemistry, University of Oxford, South Parks Road, Oxford OX1 3QU, UK
| | - Gerd Schneider
- Helmholtz Zentrum Berlin für Materialien und Energie GmbH, Wilhelm-Conrad-Röntgen Campus, 12489 Berlin, Germany
| | - Lynn W Enquist
- Department of Molecular Biology, Princeton Neuroscience Institute, Princeton University, Washington Road, Princeton, NJ 08544, USA
| | - Jürgen M Plitzko
- Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Am Klopferspitz 18, 82152 Martinsried, Germany
| | - Thomas C Mettenleiter
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, 17493 Greifswald-Insel Riems, Germany.
| | - Kay Grünewald
- Oxford Particle Imaging Centre, Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Roosevelt Drive, Oxford OX3 7BN, UK.
| |
Collapse
|
4
|
Demircioglu FE, Sosa BA, Ingram J, Ploegh HL, Schwartz TU. Structures of TorsinA and its disease-mutant complexed with an activator reveal the molecular basis for primary dystonia. eLife 2016; 5:e17983. [PMID: 27490483 PMCID: PMC4999309 DOI: 10.7554/elife.17983] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Accepted: 08/03/2016] [Indexed: 01/07/2023] Open
Abstract
The most common cause of early onset primary dystonia, a neuromuscular disease, is a glutamate deletion (ΔE) at position 302/303 of TorsinA, a AAA+ ATPase that resides in the endoplasmic reticulum. While the function of TorsinA remains elusive, the ΔE mutation is known to diminish binding of two TorsinA ATPase activators: lamina-associated protein 1 (LAP1) and its paralog, luminal domain like LAP1 (LULL1). Using a nanobody as a crystallization chaperone, we obtained a 1.4 Å crystal structure of human TorsinA in complex with LULL1. This nanobody likewise stabilized the weakened TorsinAΔE-LULL1 interaction, which enabled us to solve its structure at 1.4 Å also. A comparison of these structures shows, in atomic detail, the subtle differences in activator interactions that separate the healthy from the diseased state. This information may provide a structural platform for drug development, as a small molecule that rescues TorsinAΔE could serve as a cure for primary dystonia.
Collapse
Affiliation(s)
- F Esra Demircioglu
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Brian A Sosa
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States
| | - Jessica Ingram
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Hidde L Ploegh
- Whitehead Institute for Biomedical Research, Cambridge, United States
| | - Thomas U Schwartz
- Department of Biology, Massachusetts Institute of Technology, Cambridge, United States,
| |
Collapse
|
5
|
Kim YC, Snoberger A, Schupp J, Smith DM. ATP binding to neighbouring subunits and intersubunit allosteric coupling underlie proteasomal ATPase function. Nat Commun 2015; 6:8520. [PMID: 26465836 PMCID: PMC4608255 DOI: 10.1038/ncomms9520] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Accepted: 08/30/2015] [Indexed: 12/31/2022] Open
Abstract
The primary functions of the proteasome are driven by a highly allosteric ATPase complex. ATP binding to only two subunits in this hexameric complex triggers substrate binding, ATPase–20S association and 20S gate opening. However, it is unclear how ATP binding and hydrolysis spatially and temporally coordinates these allosteric effects to drive substrate translocation into the 20S. Here, we use FRET to show that the proteasomal ATPases from eukaryotes (RPTs) and archaea (PAN) bind ATP with high affinity at neighbouring subunits, which complements the well-established spiral-staircase topology of the 26S ATPases. We further show that two conserved arginine fingers in PAN located at the subunit interface work together as a single allosteric unit to mediate the allosteric effects of ATP binding, without altering the nucleotide-binding pattern. Rapid kinetics analysis also shows that ring resetting of a sequential hydrolysis mechanism can be explained by thermodynamic equilibrium binding of ATP. These data support a model whereby these two functionally distinct allosteric networks cooperate to translocate polypeptides into the 20S for degradation. The 26S proteasome contains a hexamer of ATPase subunits, which binds, unfolds and translocates substrates in an ATP-dependent manner. Kim et al. use FRET to show that ATP binding preferentially occurs at neighbouring subunits of the hexamer, and identify two allosteric systems that coordinate translocation.
Collapse
Affiliation(s)
- Young-Chan Kim
- Department of Biochemistry, West Virginia University, 1 Medical Center Drive, Morgantown, West Virginia 26506, USA
| | - Aaron Snoberger
- Department of Biochemistry, West Virginia University, 1 Medical Center Drive, Morgantown, West Virginia 26506, USA
| | - Jane Schupp
- Department of Biochemistry, West Virginia University, 1 Medical Center Drive, Morgantown, West Virginia 26506, USA
| | - David M Smith
- Department of Biochemistry, West Virginia University, 1 Medical Center Drive, Morgantown, West Virginia 26506, USA
| |
Collapse
|
6
|
Abstract
Torsin ATPases (Torsins) belong to the widespread AAA+ (ATPases associated with a variety of cellular activities) family of ATPases, which share structural similarity but have diverse cellular functions. Torsins are outliers in this family because they lack many characteristics of typical AAA+ proteins, and they are the only members of the AAA+ family located in the endoplasmic reticulum and contiguous perinuclear space. While it is clear that Torsins have essential roles in many, if not all metazoans, their precise cellular functions remain elusive. Studying Torsins has significant medical relevance since mutations in Torsins or Torsin-associated proteins result in a variety of congenital human disorders, the most frequent of which is early-onset torsion (DYT1) dystonia, a severe movement disorder. A better understanding of the Torsin system is needed to define the molecular etiology of these diseases, potentially enabling corrective therapy. Here, we provide a comprehensive overview of the Torsin system in metazoans, discuss functional clues obtained from various model systems and organisms and provide a phylogenetic and structural analysis of Torsins and their regulatory cofactors in relation to disease-causative mutations. Moreover, we review recent data that have led to a dramatically improved understanding of these machines at a molecular level, providing a foundation for investigating the molecular defects underlying the associated movement disorders. Lastly, we discuss our ideas on how recent progress may be utilized to inform future studies aimed at determining the cellular role(s) of these atypical molecular machines and their implications for dystonia treatment options.
Collapse
Affiliation(s)
- April E Rose
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Rebecca S H Brown
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and
| | - Christian Schlieker
- a Department of Molecular Biophysics and Biochemistry , Yale University , New Haven , CT , USA and.,b Department of Cell Biology , Yale School of Medicine , New Haven , CT , USA
| |
Collapse
|