1
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Weber J, Legal T, Lezcano AP, Gluszek-Kustusz A, Paterson C, Eibes S, Barisic M, Davies OR, Welburn JPI. A conserved CENP-E region mediates BubR1-independent recruitment to the outer corona at mitotic onset. Curr Biol 2024; 34:1133-1141.e4. [PMID: 38354735 DOI: 10.1016/j.cub.2024.01.042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Revised: 11/28/2023] [Accepted: 01/16/2024] [Indexed: 02/16/2024]
Abstract
The outer corona plays an essential role at the onset of mitosis by expanding to maximize microtubule attachment to kinetochores.1,2 The low-density structure of the corona forms through the expansion of unattached kinetochores. It comprises the RZZ complex, the dynein adaptor Spindly, the plus-end directed microtubule motor centromere protein E (CENP-E), and the Mad1/Mad2 spindle-assembly checkpoint proteins.3,4,5,6,7,8,9,10 CENP-E specifically associates with unattached kinetochores to facilitate chromosome congression,11,12,13,14,15,16 interacting with BubR1 at the kinetochore through its C-terminal region (2091-2358).17,18,19,20,21 We recently showed that CENP-E recruitment to BubR1 at the kinetochores is both rapid and essential for correct chromosome alignment. However, CENP-E is also recruited to the outer corona by a second, slower pathway that is currently undefined.19 Here, we show that BubR1-independent localization of CENP-E is mediated by a conserved loop that is essential for outer-corona targeting. We provide a structural model of the entire CENP-E kinetochore-targeting domain combining X-ray crystallography and Alphafold2. We reveal that maximal recruitment of CENP-E to unattached kinetochores critically depends on BubR1 and the outer corona, including dynein. Ectopic expression of the CENP-E C-terminal domain recruits the RZZ complex, Mad1, and Spindly, and prevents kinetochore biorientation in cells. We propose that BubR1-recruited CENP-E, in addition to its essential role in chromosome alignment to the metaphase plate, contributes to the recruitment of outer corona proteins through interactions with the CENP-E corona-targeting domain to facilitate the rapid capture of microtubules for efficient chromosome alignment and mitotic progression.
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Affiliation(s)
- Jeraldine Weber
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Thibault Legal
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Alicia Perez Lezcano
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Agata Gluszek-Kustusz
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Calum Paterson
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Susana Eibes
- Cell Division and Cytoskeleton, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark
| | - Marin Barisic
- Cell Division and Cytoskeleton, Danish Cancer Institute, Strandboulevarden 49, 2100 Copenhagen, Denmark; Department of Cellular and Molecular Medicine, Faculty of Health and Medical Sciences, University of Copenhagen, 3C Blegdamsvej, 2200 Copenhagen N, Denmark
| | - Owen R Davies
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK
| | - Julie P I Welburn
- Wellcome Centre for Cell Biology, School of Biological Sciences, University of Edinburgh, Edinburgh, Scotland EH9 3BF, UK.
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2
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Gurusaran M, Erlandsen BS, Davies OR. The crystal structure of SUN1-KASH6 reveals an asymmetric LINC complex architecture compatible with nuclear membrane insertion. Commun Biol 2024; 7:138. [PMID: 38291267 PMCID: PMC10827754 DOI: 10.1038/s42003-024-05794-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2023] [Accepted: 01/08/2024] [Indexed: 02/01/2024] Open
Abstract
The LINC complex transmits cytoskeletal forces into the nucleus to control the structure and movement of nuclear contents. It is formed of nuclear SUN and cytoplasmic KASH proteins, which interact within the nuclear lumen, immediately below the outer nuclear membrane. However, the symmetrical location of KASH molecules within SUN-KASH complexes in previous crystal structures has been difficult to reconcile with the steric requirements for insertion of their immediately upstream transmembrane helices into the outer nuclear membrane. Here, we report the crystal structure of the SUN-KASH complex between SUN1 and JAW1/LRMP (KASH6) in an asymmetric 9:6 configuration. This intertwined assembly involves two distinct KASH conformations such that all six KASH molecules emerge on the same molecular surface. Hence, they are ideally positioned for insertion of upstream sequences into the outer nuclear membrane. Thus, we report a SUN-KASH complex architecture that appears to be directly compatible with its biological role.
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Affiliation(s)
- Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Benedikte S Erlandsen
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK
| | - Owen R Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
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3
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Alexander LT, Durairaj J, Kryshtafovych A, Abriata LA, Bayo Y, Bhabha G, Breyton C, Caulton SG, Chen J, Degroux S, Ekiert DC, Erlandsen BS, Freddolino PL, Gilzer D, Greening C, Grimes JM, Grinter R, Gurusaran M, Hartmann MD, Hitchman CJ, Keown JR, Kropp A, Kursula P, Lovering AL, Lemaitre B, Lia A, Liu S, Logotheti M, Lu S, Markússon S, Miller MD, Minasov G, Niemann HH, Opazo F, Phillips GN, Davies OR, Rommelaere S, Rosas‐Lemus M, Roversi P, Satchell K, Smith N, Wilson MA, Wu K, Xia X, Xiao H, Zhang W, Zhou ZH, Fidelis K, Topf M, Moult J, Schwede T. Protein target highlights in CASP15: Analysis of models by structure providers. Proteins 2023; 91:1571-1599. [PMID: 37493353 PMCID: PMC10792529 DOI: 10.1002/prot.26545] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2023] [Accepted: 06/15/2023] [Indexed: 07/27/2023]
Abstract
We present an in-depth analysis of selected CASP15 targets, focusing on their biological and functional significance. The authors of the structures identify and discuss key protein features and evaluate how effectively these aspects were captured in the submitted predictions. While the overall ability to predict three-dimensional protein structures continues to impress, reproducing uncommon features not previously observed in experimental structures is still a challenge. Furthermore, instances with conformational flexibility and large multimeric complexes highlight the need for novel scoring strategies to better emphasize biologically relevant structural regions. Looking ahead, closer integration of computational and experimental techniques will play a key role in determining the next challenges to be unraveled in the field of structural molecular biology.
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Affiliation(s)
- Leila T. Alexander
- BiozentrumUniversity of BaselBaselSwitzerland
- Computational Structural BiologySIB Swiss Institute of BioinformaticsBaselSwitzerland
| | - Janani Durairaj
- BiozentrumUniversity of BaselBaselSwitzerland
- Computational Structural BiologySIB Swiss Institute of BioinformaticsBaselSwitzerland
| | | | - Luciano A. Abriata
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Yusupha Bayo
- Department of BiosciencesUniversity of MilanoMilanItaly
- IBBA‐CNR Unit of MilanoInstitute of Agricultural Biology and BiotechnologyMilanItaly
| | - Gira Bhabha
- Department of Cell BiologyNew York University School of MedicineNew YorkNew YorkUSA
| | | | | | - James Chen
- Department of Cell BiologyNew York University School of MedicineNew YorkNew YorkUSA
| | | | - Damian C. Ekiert
- Department of Cell BiologyNew York University School of MedicineNew YorkNew YorkUSA
- Department of MicrobiologyNew York University School of MedicineNew YorkNew YorkUSA
| | - Benedikte S. Erlandsen
- Wellcome Centre for Cell BiologyInstitute of Cell Biology, University of EdinburghEdinburghUK
| | - Peter L. Freddolino
- Department of Biological Chemistry, Computational Medicine and BioinformaticsUniversity of MichiganAnn ArborMichiganUSA
| | - Dominic Gilzer
- Department of ChemistryBielefeld UniversityBielefeldGermany
| | - Chris Greening
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityClaytonVictoriaAustralia
- Securing Antarctica's Environmental FutureMonash UniversityClaytonVictoriaAustralia
- Centre to Impact AMRMonash UniversityClaytonVictoriaAustralia
- ARC Research Hub for Carbon Utilisation and RecyclingMonash UniversityClaytonVictoriaAustralia
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Rhys Grinter
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityClaytonVictoriaAustralia
- Centre for Electron Microscopy of Membrane ProteinsMonash Institute of Pharmaceutical SciencesParkvilleVictoriaAustralia
| | - Manickam Gurusaran
- Wellcome Centre for Cell BiologyInstitute of Cell Biology, University of EdinburghEdinburghUK
| | - Marcus D. Hartmann
- Max Planck Institute for BiologyTübingenGermany
- Interfaculty Institute of Biochemistry, University of TübingenTübingenGermany
| | - Charlie J. Hitchman
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLeicesterUK
| | - Jeremy R. Keown
- Division of Structural Biology, Wellcome Centre for Human GeneticsUniversity of OxfordOxfordUK
| | - Ashleigh Kropp
- Department of Microbiology, Biomedicine Discovery InstituteMonash UniversityClaytonVictoriaAustralia
| | - Petri Kursula
- Department of BiomedicineUniversity of BergenBergenNorway
- Faculty of Biochemistry and Molecular Medicine & Biocenter OuluUniversity of OuluOuluFinland
| | | | - Bruno Lemaitre
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Andrea Lia
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLeicesterUK
- ISPA‐CNR Unit of LecceInstitute of Sciences of Food ProductionLecceItaly
| | - Shiheng Liu
- Department of Microbiology, Immunology, and Molecular GeneticsUniversity of CaliforniaLos AngelesCaliforniaUSA
- California NanoSystems InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Maria Logotheti
- Max Planck Institute for BiologyTübingenGermany
- Interfaculty Institute of Biochemistry, University of TübingenTübingenGermany
- Present address:
Institute of BiochemistryUniversity of GreifswaldGreifswaldGermany
| | - Shuze Lu
- Lanzhou University School of Life SciencesLanzhouChina
| | | | | | - George Minasov
- Department of Microbiology‐ImmunologyNorthwestern Feinberg School of MedicineChicagoIllinoisUSA
| | | | - Felipe Opazo
- NanoTag Biotechnologies GmbHGöttingenGermany
- Institute of Neuro‐ and Sensory PhysiologyUniversity of Göttingen Medical CenterGöttingenGermany
- Center for Biostructural Imaging of Neurodegeneration (BIN)University of Göttingen Medical CenterGöttingenGermany
| | - George N. Phillips
- Department of BiosciencesRice UniversityHoustonTexasUSA
- Department of ChemistryRice UniversityHoustonTexasUSA
| | - Owen R. Davies
- Wellcome Centre for Cell BiologyInstitute of Cell Biology, University of EdinburghEdinburghUK
| | - Samuel Rommelaere
- School of Life SciencesÉcole Polytechnique Fédérale de LausanneLausanneSwitzerland
| | - Monica Rosas‐Lemus
- Department of Microbiology‐ImmunologyNorthwestern Feinberg School of MedicineChicagoIllinoisUSA
- Present address:
Department of Molecular Genetics and MicrobiologyUniversity of New MexicoAlbuquerqueNew MexicoUSA
| | - Pietro Roversi
- IBBA‐CNR Unit of MilanoInstitute of Agricultural Biology and BiotechnologyMilanItaly
- Department of Molecular and Cell Biology, Leicester Institute of Structural and Chemical BiologyUniversity of LeicesterLeicesterUK
| | - Karla Satchell
- Department of Microbiology‐ImmunologyNorthwestern Feinberg School of MedicineChicagoIllinoisUSA
| | - Nathan Smith
- Department of Biochemistry and the Redox Biology CenterUniversity of NebraskaLincolnNebraskaUSA
| | - Mark A. Wilson
- Department of Biochemistry and the Redox Biology CenterUniversity of NebraskaLincolnNebraskaUSA
| | - Kuan‐Lin Wu
- Department of ChemistryRice UniversityHoustonTexasUSA
| | - Xian Xia
- Department of Microbiology, Immunology, and Molecular GeneticsUniversity of CaliforniaLos AngelesCaliforniaUSA
- California NanoSystems InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA
| | - Han Xiao
- Department of BiosciencesRice UniversityHoustonTexasUSA
- Department of ChemistryRice UniversityHoustonTexasUSA
- Department of BioengineeringRice UniversityHoustonTexasUSA
| | - Wenhua Zhang
- Lanzhou University School of Life SciencesLanzhouChina
| | - Z. Hong Zhou
- Department of Microbiology, Immunology, and Molecular GeneticsUniversity of CaliforniaLos AngelesCaliforniaUSA
- California NanoSystems InstituteUniversity of CaliforniaLos AngelesCaliforniaUSA
| | | | - Maya Topf
- University Medical Center Hamburg‐Eppendorf (UKE)HamburgGermany
- Centre for Structural Systems BiologyLeibniz‐Institut für Virologie (LIV)HamburgGermany
| | - John Moult
- Department of Cell Biology and Molecular Genetics, Institute for Bioscience and Biotechnology ResearchUniversity of MarylandRockvilleMarylandUSA
| | - Torsten Schwede
- BiozentrumUniversity of BaselBaselSwitzerland
- Computational Structural BiologySIB Swiss Institute of BioinformaticsBaselSwitzerland
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4
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Adams IR, Davies OR. Meiotic Chromosome Structure, the Synaptonemal Complex, and Infertility. Annu Rev Genomics Hum Genet 2023; 24:35-61. [PMID: 37159901 DOI: 10.1146/annurev-genom-110122-090239] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
In meiosis, homologous chromosome synapsis is mediated by a supramolecular protein structure, the synaptonemal complex (SC), that assembles between homologous chromosome axes. The mammalian SC comprises at least eight largely coiled-coil proteins that interact and self-assemble to generate a long, zipper-like structure that holds homologous chromosomes in close proximity and promotes the formation of genetic crossovers and accurate meiotic chromosome segregation. In recent years, numerous mutations in human SC genes have been associated with different types of male and female infertility. Here, we integrate structural information on the human SC with mouse and human genetics to describe the molecular mechanisms by which SC mutations can result in human infertility. We outline certain themes in which different SC proteins are susceptible to different types of disease mutation and how genetic variants with seemingly minor effects on SC proteins may act as dominant-negative mutations in which the heterozygous state is pathogenic.
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Affiliation(s)
- Ian R Adams
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, United Kingdom;
| | - Owen R Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, United Kingdom;
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5
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Gurusaran M, Biemans JJ, Wood CW, Davies OR. Molecular insights into LINC complex architecture through the crystal structure of a luminal trimeric coiled-coil domain of SUN1. Front Cell Dev Biol 2023; 11:1144277. [PMID: 37416798 PMCID: PMC10320395 DOI: 10.3389/fcell.2023.1144277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2023] [Accepted: 06/09/2023] [Indexed: 07/08/2023] Open
Abstract
The LINC complex, consisting of interacting SUN and KASH proteins, mechanically couples nuclear contents to the cytoskeleton. In meiosis, the LINC complex transmits microtubule-generated forces to chromosome ends, driving the rapid chromosome movements that are necessary for synapsis and crossing over. In somatic cells, it defines nuclear shape and positioning, and has a number of specialised roles, including hearing. Here, we report the X-ray crystal structure of a coiled-coiled domain of SUN1's luminal region, providing an architectural foundation for how SUN1 traverses the nuclear lumen, from the inner nuclear membrane to its interaction with KASH proteins at the outer nuclear membrane. In combination with light and X-ray scattering, molecular dynamics and structure-directed modelling, we present a model of SUN1's entire luminal region. This model highlights inherent flexibility between structured domains, and raises the possibility that domain-swap interactions may establish a LINC complex network for the coordinated transmission of cytoskeletal forces.
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Affiliation(s)
- Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Jelle J. Biemans
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Christopher W. Wood
- Institute of Quantitative Biology, Biochemistry and Biotechnology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
| | - Owen R. Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, Scotland, United Kingdom
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6
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Garner KE, Salter A, Lau CK, Gurusaran M, Villemant CM, Granger EP, McNee G, Woodman PG, Davies OR, Burke BE, Allan VJ. The meiotic LINC complex component KASH5 is an activating adaptor for cytoplasmic dynein. J Cell Biol 2023; 222:e202204042. [PMID: 36946995 PMCID: PMC10071310 DOI: 10.1083/jcb.202204042] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 12/15/2022] [Accepted: 02/10/2023] [Indexed: 03/23/2023] Open
Abstract
Cytoplasmic dynein-driven movement of chromosomes during prophase I of mammalian meiosis is essential for synapsis and genetic exchange. Dynein connects to chromosome telomeres via KASH5 and SUN1 or SUN2, which together span the nuclear envelope. Here, we show that KASH5 promotes dynein motility in vitro, and cytosolic KASH5 inhibits dynein's interphase functions. KASH5 interacts with a dynein light intermediate chain (DYNC1LI1 or DYNC1LI2) via a conserved helix in the LIC C-terminal, and this region is also needed for dynein's recruitment to other cellular membranes. KASH5's N-terminal EF-hands are essential as the interaction with dynein is disrupted by mutation of key calcium-binding residues, although it is not regulated by cellular calcium levels. Dynein can be recruited to KASH5 at the nuclear envelope independently of dynactin, while LIS1 is essential for dynactin incorporation into the KASH5-dynein complex. Altogether, we show that the transmembrane protein KASH5 is an activating adaptor for dynein and shed light on the hierarchy of assembly of KASH5-dynein-dynactin complexes.
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Affiliation(s)
- Kirsten E.L. Garner
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Anna Salter
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- A*STAR Institute of Medical Biology, Singapore, Singapore
| | - Clinton K. Lau
- MRC Laboratory of Molecular Biology, Francis Crick Avenue, Cambridge Biomedical Campus, Cambridge, UK
| | - Manickam Gurusaran
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Cécile M. Villemant
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Elizabeth P. Granger
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Gavin McNee
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Philip G. Woodman
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
| | - Owen R. Davies
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK
| | - Brian E. Burke
- A*STAR Institute of Medical Biology, Singapore, Singapore
| | - Victoria J. Allan
- School of Biological Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- A*STAR Institute of Medical Biology, Singapore, Singapore
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7
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Crichton JH, Dunce JM, Dunne OM, Salmon LJ, Devenney PS, Lawson J, Adams IR, Davies OR. Structural maturation of SYCP1-mediated meiotic chromosome synapsis by SYCE3. Nat Struct Mol Biol 2023; 30:188-199. [PMID: 36635604 PMCID: PMC7614228 DOI: 10.1038/s41594-022-00909-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2018] [Accepted: 12/06/2022] [Indexed: 01/13/2023]
Abstract
In meiosis, a supramolecular protein structure, the synaptonemal complex (SC), assembles between homologous chromosomes to facilitate their recombination. Mammalian SC formation is thought to involve hierarchical zipper-like assembly of an SYCP1 protein lattice that recruits stabilizing central element (CE) proteins as it extends. Here we combine biochemical approaches with separation-of-function mutagenesis in mice to show that, rather than stabilizing the SYCP1 lattice, the CE protein SYCE3 actively remodels this structure during synapsis. We find that SYCP1 tetramers undergo conformational change into 2:1 heterotrimers on SYCE3 binding, removing their assembly interfaces and disrupting the SYCP1 lattice. SYCE3 then establishes a new lattice by its self-assembly mimicking the role of the disrupted interface in tethering together SYCP1 dimers. SYCE3 also interacts with CE complexes SYCE1-SIX6OS1 and SYCE2-TEX12, providing a mechanism for their recruitment. Thus, SYCE3 remodels the SYCP1 lattice into a CE-binding integrated SYCP1-SYCE3 lattice to achieve long-range synapsis by a mature SC.
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Affiliation(s)
- James H Crichton
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - James M Dunce
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Orla M Dunne
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
- Vienna BioCenter Core Facilities GmbH, Vienna, Austria
| | - Lucy J Salmon
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Paul S Devenney
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Jennifer Lawson
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK
| | - Ian R Adams
- MRC Human Genetics Unit, MRC Institute of Genetics and Cancer, University of Edinburgh, Edinburgh, UK.
| | - Owen R Davies
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
- Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Edinburgh, UK.
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8
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Sandhu S, Sou IF, Hunter JE, Salmon L, Wilson CL, Perkins ND, Hunter N, Davies OR, McClurg UL. Centrosome dysfunction associated with somatic expression of the synaptonemal complex protein TEX12. Commun Biol 2021; 4:1371. [PMID: 34880391 PMCID: PMC8654964 DOI: 10.1038/s42003-021-02887-4] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Accepted: 11/12/2021] [Indexed: 12/22/2022] Open
Abstract
The synaptonemal complex (SC) is a supramolecular protein scaffold that mediates chromosome synapsis and facilitates crossing over during meiosis. In mammals, SC proteins are generally assumed to have no other function. Here, we show that SC protein TEX12 also localises to centrosomes during meiosis independently of chromosome synapsis. In somatic cells, ectopically expressed TEX12 similarly localises to centrosomes, where it is associated with centrosome amplification, a pathology correlated with cancer development. Indeed, TEX12 is identified as a cancer-testis antigen and proliferation of some cancer cells is TEX12-dependent. Moreover, somatic expression of TEX12 is aberrantly activated via retinoic acid signalling, which is commonly disregulated in cancer. Structure-function analysis reveals that phosphorylation of TEX12 on tyrosine 48 is important for centrosome amplification but not for recruitment of TEX12 to centrosomes. We conclude that TEX12 normally localises to meiotic centrosomes, but its misexpression in somatic cells can contribute to pathological amplification and dysfunction of centrosomes in cancers. Sandhu et al. report that the synaptonemal complex (SC) protein, TEX12, localises to centrosomes independently of the SC during meiosis. They also show that it provokes centrosome amplification in somatic cells, a pathology associated with cancer development.
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Affiliation(s)
- Sumit Sandhu
- Howard Hughes Medical Institute, Department of Microbiology and Molecular Genetics, University of California, Davis, CA, 95616, USA
| | - Ieng F Sou
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK
| | - Jill E Hunter
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Lucy Salmon
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Caroline L Wilson
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Neil D Perkins
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Neil Hunter
- Howard Hughes Medical Institute, Department of Microbiology and Molecular Genetics, University of California, Davis, CA, 95616, USA.
| | - Owen R Davies
- Biosciences Institute, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK. .,Wellcome Centre for Cell Biology, Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, EH9 3BF, UK.
| | - Urszula L McClurg
- Institute of Systems, Molecular and Integrative Biology, University of Liverpool, Liverpool, L69 7ZB, UK.
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9
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Thomas C, Wetherall B, Levasseur MD, Harris RJ, Kerridge ST, Higgins JMG, Davies OR, Madgwick S. A prometaphase mechanism of securin destruction is essential for meiotic progression in mouse oocytes. Nat Commun 2021; 12:4322. [PMID: 34262048 PMCID: PMC8280194 DOI: 10.1038/s41467-021-24554-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Accepted: 06/24/2021] [Indexed: 11/10/2022] Open
Abstract
Successful cell division relies on the timely removal of key cell cycle proteins such as securin. Securin inhibits separase, which cleaves the cohesin rings holding chromosomes together. Securin must be depleted before anaphase to ensure chromosome segregation occurs with anaphase. Here we find that in meiosis I, mouse oocytes contain an excess of securin over separase. We reveal a mechanism that promotes excess securin destruction in prometaphase I. Importantly, this mechanism relies on two phenylalanine residues within the separase-interacting segment (SIS) of securin that are only exposed when securin is not bound to separase. We suggest that these residues facilitate the removal of non-separase-bound securin ahead of metaphase, as inhibiting this period of destruction by mutating both residues causes the majority of oocytes to arrest in meiosis I. We further propose that cellular securin levels exceed the amount an oocyte is capable of removing in metaphase alone, such that the prometaphase destruction mechanism identified here is essential for correct meiotic progression in mouse oocytes.
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Affiliation(s)
- Christopher Thomas
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK. .,Max Planck Institute for Biophysical Chemistry, Gottingen, Germany.
| | - Benjamin Wetherall
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Mark D Levasseur
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Rebecca J Harris
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Scott T Kerridge
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Jonathan M G Higgins
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Owen R Davies
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.,Institute of Cell Biology, University of Edinburgh, Michael Swann Building, Max Born Crescent, Edinburgh, UK
| | - Suzanne Madgwick
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK.
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10
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Morton CR, Rzechorzek NJ, Maman JD, Kuramochi M, Sekiguchi H, Rambo R, Sasaki YC, Davies OR, Pellegrini L. Structural basis for the coiled-coil architecture of human CtIP. Open Biol 2021; 11:210060. [PMID: 34129781 PMCID: PMC8205527 DOI: 10.1098/rsob.210060] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
The DNA repair factor CtIP has a critical function in double-strand break (DSB) repair by homologous recombination, promoting the assembly of the repair apparatus at DNA ends and participating in DNA-end resection. However, the molecular mechanisms of CtIP function in DSB repair remain unclear. Here, we present an atomic model for the three-dimensional architecture of human CtIP, derived from a multi-disciplinary approach that includes X-ray crystallography, small-angle X-ray scattering (SAXS) and diffracted X-ray tracking (DXT). Our data show that CtIP adopts an extended dimer-of-dimers structure, in agreement with a role in bridging distant sites on chromosomal DNA during the recombinational repair. The zinc-binding motif in the CtIP N-terminus alters dynamically the coiled-coil structure, with functional implications for the long-range interactions of CtIP with DNA. Our results provide a structural basis for the three-dimensional arrangement of chains in the CtIP tetramer, a key aspect of CtIP function in DNA DSB repair.
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Affiliation(s)
- C R Morton
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - N J Rzechorzek
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - J D Maman
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
| | - M Kuramochi
- Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Kashiwa, Japan
| | - H Sekiguchi
- Centre for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - R Rambo
- Diamond Light Source, Didcot, Oxfordshire OX11 0DE, UK
| | - Y C Sasaki
- Graduate School of Frontier Sciences, The University of Tokyo, Tokyo, Japan.,AIST-UTokyo Advanced Operando-Measurement Technology Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology, Kashiwa, Japan.,Centre for Synchrotron Radiation Research, Japan Synchrotron Radiation Research Institute, Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
| | - O R Davies
- Institute of Cell Biology, University of Edinburgh, Edinburgh EH9 3BF, UK
| | - L Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, UK
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11
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Sánchez Rodríguez F, Simpkin AJ, Davies OR, Keegan RM, Rigden DJ. Helical ensembles outperform ideal helices in molecular replacement. Acta Crystallogr D Struct Biol 2020; 76:962-970. [PMID: 33021498 PMCID: PMC7543657 DOI: 10.1107/s205979832001133x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Accepted: 08/18/2020] [Indexed: 03/21/2023]
Abstract
Helical ensembles solve more structures by MR with AMPLE than do ideal helices and at no greater CPU cost. The conventional approach in molecular replacement is the use of a related structure as a search model. However, this is not always possible as the availability of such structures can be scarce for poorly characterized families of proteins. In these cases, alternative approaches can be explored, such as the use of small ideal fragments that share high, albeit local, structural similarity with the unknown protein. Earlier versions of AMPLE enabled the trialling of a library of ideal helices, which worked well for largely helical proteins at suitable resolutions. Here, the performance of libraries of helical ensembles created by clustering helical segments is explored. The impacts of different B-factor treatments and different degrees of structural heterogeneity are explored. A 30% increase in the number of solutions obtained by AMPLE was observed when using this new set of ensembles compared with the performance with ideal helices. The boost in performance was notable across three different fold classes: transmembrane, globular and coiled-coil structures. Furthermore, the increased effectiveness of these ensembles was coupled to a reduction in the time required by AMPLE to reach a solution. AMPLE users can now take full advantage of this new library of search models by activating the ‘helical ensembles’ mode.
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Affiliation(s)
- Filomeno Sánchez Rodríguez
- Institute of Structural, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Adam J Simpkin
- Institute of Structural, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Ronan M Keegan
- UKRI-STFC, Rutherford Appleton Laboratory, Research Complex at Harwell, Didcot OX11 0FA, United Kingdom
| | - Daniel J Rigden
- Institute of Structural, Molecular and Integrative Biology, University of Liverpool, Liverpool L69 7ZB, United Kingdom
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12
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Sánchez-Sáez F, Gómez-H L, Dunne OM, Gallego-Páramo C, Felipe-Medina N, Sánchez-Martín M, Llano E, Pendas AM, Davies OR. Meiotic chromosome synapsis depends on multivalent SYCE1-SIX6OS1 interactions that are disrupted in cases of human infertility. Sci Adv 2020; 6:6/36/eabb1660. [PMID: 32917591 PMCID: PMC7467691 DOI: 10.1126/sciadv.abb1660] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Accepted: 07/17/2020] [Indexed: 05/14/2023]
Abstract
Meiotic reductional division depends on the synaptonemal complex (SC), a supramolecular protein assembly that mediates homologous chromosomes synapsis and promotes crossover formation. The mammalian SC has eight structural components, including SYCE1, the only central element protein with known causative mutations in human infertility. We combine mouse genetics, cellular, and biochemical studies to reveal that SYCE1 undergoes multivalent interactions with SC component SIX6OS1. The N terminus of SIX6OS1 binds and disrupts SYCE1's core dimeric structure to form a 1:1 complex, while their downstream sequences provide a distinct second interface. These interfaces are separately disrupted by SYCE1 mutations associated with nonobstructive azoospermia and premature ovarian failure (POF), respectively. Mice harboring SYCE1's POF mutation and a targeted deletion within SIX6OS1's N terminus are infertile with failure of chromosome synapsis. We conclude that both SYCE1-SIX6OS1 binding interfaces are essential for SC assembly, thus explaining how SYCE1's reported clinical mutations give rise to human infertility.
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Affiliation(s)
- Fernando Sánchez-Sáez
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain
| | - Laura Gómez-H
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain
| | - Orla M Dunne
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Cristina Gallego-Páramo
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK
| | - Natalia Felipe-Medina
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain
| | | | - Elena Llano
- Departamento de Fisiología y Farmacología, Universidad de Salamanca, Salamanca, Spain
| | - Alberto M Pendas
- Molecular Mechanisms Program, Centro de Investigación del Cáncer and Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), Salamanca, Spain.
| | - Owen R Davies
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, UK.
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13
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Landewé RB, van der Heijde D, Dougados M, Baraliakos X, Van den Bosch FE, Gaffney K, Bauer L, Hoepken B, Davies OR, de Peyrecave N, Thomas K, Gensler L. Maintenance of clinical remission in early axial spondyloarthritis following certolizumab pegol dose reduction. Ann Rheum Dis 2020; 79:920-928. [PMID: 32381562 PMCID: PMC7307216 DOI: 10.1136/annrheumdis-2019-216839] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Revised: 04/09/2020] [Accepted: 04/13/2020] [Indexed: 12/11/2022]
Abstract
Background The best strategy for maintaining clinical remission in patients with axial spondyloarthritis (axSpA) has not been defined. C-OPTIMISE compared dose continuation, reduction and withdrawal of the tumour necrosis factor inhibitor certolizumab pegol (CZP) following achievement of sustained remission in patients with early axSpA. Methods C-OPTIMISE was a two-part, multicentre phase 3b study in adults with early active axSpA (radiographic or non-radiographic). During the 48-week open-label induction period, patients received CZP 200 mg every 2 weeks (Q2W). At Week 48, patients in sustained remission (Ankylosing Spondylitis Disease Activity Score (ASDAS) <1.3 at Weeks 32/36 and 48) were randomised to double-blind CZP 200 mg Q2W (full maintenance dose), CZP 200 mg every 4 weeks (Q4W; reduced maintenance dose) or placebo (withdrawal) for a further 48 weeks. The primary endpoint was remaining flare-free (flare: ASDAS ≥2.1 at two consecutive visits or ASDAS >3.5 at any time point) during the double-blind period. Results At Week 48, 43.9% (323/736) patients achieved sustained remission, of whom 313 were randomised to CZP full maintenance dose, CZP reduced maintenance dose or placebo. During Weeks 48 to 96, 83.7% (87/104), 79.0% (83/105) and 20.2% (21/104) of patients receiving the full maintenance dose, reduced maintenance dose or placebo, respectively, were flare-free (p<0.001 vs placebo in both CZP groups). Responses in radiographic and non-radiographic axSpA patients were comparable. Conclusions Patients with early axSpA who achieve sustained remission at 48 weeks can reduce their CZP maintenance dose; however, treatment should not be completely discontinued due to the high risk of flare following CZP withdrawal. Trial registration number NCT02505542, ClinicalTrials.gov.
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Affiliation(s)
- Robert Bm Landewé
- Amsterdam Rheumatology & Clinical Immunology Center, Amsterdam, The Netherlands .,Zuyderland Medical Center, Heerlen, The Netherlands
| | | | - Maxime Dougados
- Hopital Cochin, Rheumatology, Université Paris Descartes, Paris, France
| | - Xenofon Baraliakos
- Rheumazentrum Ruhrgebiet, Ruhr University Bochum, Bochum, Herne, Germany
| | - Filip E Van den Bosch
- Department of Internal Medicine and Pediatrics, VIB Center for Inflammation Research, Ghent University, Ghent, Belgium
| | - Karl Gaffney
- Rheumatology Department, Norfolk and Norwich University Hospital NHS Foundation Trust, Norwich, UK
| | | | | | | | | | | | - Lianne Gensler
- University of California San Francisco, San Francisco, California, USA
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14
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Zhang J, Gurusaran M, Fujiwara Y, Zhang K, Echbarthi M, Vorontsov E, Guo R, Pendlebury DF, Alam I, Livera G, Emmanuelle M, Wang PJ, Nandakumar J, Davies OR, Shibuya H. The BRCA2-MEILB2-BRME1 complex governs meiotic recombination and impairs the mitotic BRCA2-RAD51 function in cancer cells. Nat Commun 2020; 11:2055. [PMID: 32345962 PMCID: PMC7188823 DOI: 10.1038/s41467-020-15954-x] [Citation(s) in RCA: 29] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2019] [Accepted: 04/03/2020] [Indexed: 11/10/2022] Open
Abstract
Breast cancer susceptibility gene II (BRCA2) is central in homologous recombination (HR). In meiosis, BRCA2 binds to MEILB2 to localize to DNA double-strand breaks (DSBs). Here, we identify BRCA2 and MEILB2-associating protein 1 (BRME1), which functions as a stabilizer of MEILB2 by binding to an α-helical N-terminus of MEILB2 and preventing MEILB2 self-association. BRCA2 binds to the C-terminus of MEILB2, resulting in the formation of the BRCA2-MEILB2-BRME1 ternary complex. In Brme1 knockout (Brme1-/-) mice, the BRCA2-MEILB2 complex is destabilized, leading to defects in DSB repair, homolog synapsis, and crossover formation. Persistent DSBs in Brme1-/- reactivate the somatic-like DNA-damage response, which repairs DSBs but cannot complement the crossover formation defects. Further, MEILB2-BRME1 is activated in many human cancers, and somatically expressed MEILB2-BRME1 impairs mitotic HR. Thus, the meiotic BRCA2 complex is central in meiotic HR, and its misregulation is implicated in cancer development.
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Affiliation(s)
- Jingjing Zhang
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Manickam Gurusaran
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Yasuhiro Fujiwara
- Institute for Quantitative Biosciences, University of Tokyo, 1-1-1 Yayoi, Tokyo, 113-0032, Japan
| | - Kexin Zhang
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Meriem Echbarthi
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Egor Vorontsov
- Proteomics Core Facility, Sahlgrenska Academy, University of Gothenburg, SE-40530, Gothenburg, Sweden
| | - Rui Guo
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Devon F Pendlebury
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Intekhab Alam
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH, 44106, USA
| | - Gabriel Livera
- Laboratory of Development of the Gonads, UMRE008 Genetic Stability Stem Cells and Radiation, Université de Paris, Université Paris Saclay, CEA, F-92265, Fontenay aux Roses, France
| | - Martini Emmanuelle
- Laboratory of Development of the Gonads, UMRE008 Genetic Stability Stem Cells and Radiation, Université de Paris, Université Paris Saclay, CEA, F-92265, Fontenay aux Roses, France
| | - P Jeremy Wang
- Department of Biomedical Sciences, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA, 19104, USA
| | - Jayakrishnan Nandakumar
- Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, 48109, USA
- Program in Chemical Biology, University of Michigan, Ann Arbor, MI, 48109, USA
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Hiroki Shibuya
- Department of Chemistry and Molecular Biology, University of Gothenburg, SE-40530, Gothenburg, Sweden.
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15
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Thomas JMH, Keegan RM, Rigden DJ, Davies OR. Extending the scope of coiled-coil crystal structure solution by AMPLE through improved ab initio modelling. Acta Crystallogr D Struct Biol 2020; 76:272-284. [PMID: 32133991 PMCID: PMC7057219 DOI: 10.1107/s2059798320000443] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 01/14/2020] [Indexed: 11/10/2022] Open
Abstract
The phase problem remains a major barrier to overcome in protein structure solution by X-ray crystallography. In recent years, new molecular-replacement approaches using ab initio models and ideal secondary-structure components have greatly contributed to the solution of novel structures in the absence of clear homologues in the PDB or experimental phasing information. This has been particularly successful for highly α-helical structures, and especially coiled-coils, in which the relatively rigid α-helices provide very useful molecular-replacement fragments. This has been seen within the program AMPLE, which uses clustered and truncated ensembles of numerous ab initio models in structure solution, and is already accomplished for α-helical and coiled-coil structures. Here, an expansion in the scope of coiled-coil structure solution by AMPLE is reported, which has been achieved through general improvements in the pipeline, the removal of tNCS correction in molecular replacement and two improved methods for ab initio modelling. Of the latter improvements, enforcing the modelling of elongated helices overcame the bias towards globular folds and provided a rapid method (equivalent to the time requirements of the existing modelling procedures in AMPLE) for enhanced solution. Further, the modelling of two-, three- and four-helical oligomeric coiled-coils, and the use of full/partial oligomers in molecular replacement, provided additional success in difficult and lower resolution cases. Together, these approaches have enabled the solution of a number of parallel/antiparallel dimeric, trimeric and tetrameric coiled-coils at resolutions as low as 3.3 Å, and have thus overcome previous limitations in AMPLE and provided a new functionality in coiled-coil structure solution at lower resolutions. These new approaches have been incorporated into a new release of AMPLE in which automated elongated monomer and oligomer modelling may be activated by selecting `coiled-coil' mode.
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Affiliation(s)
- Jens M. H. Thomas
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
| | - Ronan M. Keegan
- Research Complex at Harwell, STFC Rutherford Appleton Laboratory, Didcot OX11 0FA, England
| | - Daniel J. Rigden
- Institute of Integrative Biology, University of Liverpool, Liverpool L69 7ZB, England
| | - Owen R. Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, England
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16
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Prior C, Davies OR, Bruce D, Pohl E. Obtaining Tertiary Protein Structures by the ab Initio Interpretation of Small Angle X-ray Scattering Data. J Chem Theory Comput 2020; 16:1985-2001. [PMID: 32023061 PMCID: PMC7145352 DOI: 10.1021/acs.jctc.9b01010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
![]()
Small angle X-ray scattering (SAXS)
is an important tool for investigating
the structure of proteins in solution. We present a novel ab initio
method representing polypeptide chains as discrete curves used to
derive a meaningful three-dimensional model from only the primary sequence and SAXS data. High resolution structures were
used to generate probability density functions for each common secondary
structural element found in proteins, which are used to place realistic
restraints on the model curve’s geometry. This is coupled with
a novel explicit hydration shell model in order to derive physically
meaningful three-dimensional models by optimizing against experimental
SAXS data. The efficacy of this model is verified on an established
benchmark protein set, and then it is used to predict the lysozyme
structure using only its primary sequence and SAXS data. The method
is used to generate a biologically plausible model of the coiled-coil
component of the human synaptonemal complex central element protein.
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Affiliation(s)
- Christopher Prior
- Department of Mathematical Sciences, Durham University, Durham DH1 3LE, United Kingdom
| | - Owen R Davies
- Institute for Cell and Molecular Bioscience, Medical School, University of Newcastle, Newcastle upon Tyne, NE2 4HH, United Kingdom
| | - Daniel Bruce
- Department of Biosciences Durham University, Durham DH1 3LE, United Kingdom.,Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
| | - Ehmke Pohl
- Department of Biosciences Durham University, Durham DH1 3LE, United Kingdom.,Department of Chemistry, Durham University, Durham DH1 3LE, United Kingdom
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17
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Lepore R, Kryshtafovych A, Alahuhta M, Veraszto HA, Bomble YJ, Bufton JC, Bullock AN, Caba C, Cao H, Davies OR, Desfosses A, Dunne M, Fidelis K, Goulding CW, Gurusaran M, Gutsche I, Harding CJ, Hartmann MD, Hayes CS, Joachimiak A, Leiman PG, Loppnau P, Lovering AL, Lunin VV, Michalska K, Mir-Sanchis I, Mitra AK, Moult J, Phillips GN, Pinkas DM, Rice PA, Tong Y, Topf M, Walton JD, Schwede T. Target highlights in CASP13: Experimental target structures through the eyes of their authors. Proteins 2019; 87:1037-1057. [PMID: 31442339 PMCID: PMC6851490 DOI: 10.1002/prot.25805] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 08/09/2019] [Accepted: 08/19/2019] [Indexed: 01/10/2023]
Abstract
The functional and biological significance of selected CASP13 targets are described by the authors of the structures. The structural biologists discuss the most interesting structural features of the target proteins and assess whether these features were correctly reproduced in the predictions submitted to the CASP13 experiment.
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Affiliation(s)
- Rosalba Lepore
- BSC-CNS Barcelona Supercomputing Center, Barcelona, Spain
| | | | - Markus Alahuhta
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Harshul A Veraszto
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Yannick J Bomble
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Joshua C Bufton
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK.,School of Biochemistry, University of Bristol, Bristol, UK
| | - Alex N Bullock
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Cody Caba
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada
| | - Hongnan Cao
- Department of BioSciences, Rice University, Houston, Texas.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Ambroise Desfosses
- School of Biological Sciences, University of Auckland, Auckland, New Zealand.,Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Matthew Dunne
- Institute of Food, Nutrition and Health, Zurich, Switzerland
| | | | - Celia W Goulding
- Department of Molecular Biology and Biochemistry; Pharmaceutical Sciences, University of California Irvine, Irvine, California
| | - Manickam Gurusaran
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, UK
| | - Irina Gutsche
- Institut de Biologie Structurale, Université Grenoble Alpes, CEA, CNRS, Grenoble, France
| | | | - Marcus D Hartmann
- Department of Protein Evolution, Max Planck Institute for Developmental Biology, Tübingen, Germany
| | - Christopher S Hayes
- Department of Molecular, Cellular and Developmental Biology, Biomolecular Science and Engineering Program, University of California, Santa Barbara, California
| | - Andrzej Joachimiak
- Structural Biology Center, Biosciences Division, Midwest Center for Structural Genomics, Argonne.,Department of Biochemistry and Molecular Biology, University of Chicago, Chicago, Illinois
| | - Petr G Leiman
- Department of Biochemistry and Molecular Biology, Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, Texas
| | - Peter Loppnau
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | | | - Vladimir V Lunin
- Biosciences Center, National Renewable Energy Laboratory, Golden, Colorado
| | - Karolina Michalska
- Structural Biology Center, Biosciences Division, Midwest Center for Structural Genomics, Argonne
| | - Ignacio Mir-Sanchis
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - A K Mitra
- School of Biological Sciences, University of Auckland, Auckland, New Zealand
| | - John Moult
- Institute for Bioscience and Biotechnology Research, Department of Cell Biology and Molecular genetics, University of Maryland, Rockville, Maryland, USA
| | - George N Phillips
- Department of BioSciences, Rice University, Houston, Texas.,Great Lakes Bioenergy Research Center, University of Wisconsin, Madison, Wisconsin
| | - Daniel M Pinkas
- Nuffield Department of Medicine; Structural Genomics Consortium, University of Oxford, Oxford, UK
| | - Phoebe A Rice
- Department of Biochemistry and Molecular Biology, The University of Chicago, Chicago, Illinois
| | - Yufeng Tong
- Department of Chemistry and Biochemistry, University of Windsor, Windsor, Ontario, Canada.,Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Maya Topf
- Institute of Structural and Molecular Biology, Birkbeck, University College London, London, UK
| | - Jonathan D Walton
- Great Lakes Bioenergy Research Center and Department of Plant Biology, Michigan State University, East Lansing, Michigan
| | - Torsten Schwede
- Biozentrum University of Basel, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum University of Basel, Basel, Switzerland
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18
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Abstract
The synaptonemal complex (SC) is a supramolecular protein assembly that mediates homologous chromosome synapsis during meiosis. This zipper-like structure assembles in a continuous manner between homologous chromosome axes, enforcing a 100-nm separation along their entire length and providing the necessary three-dimensional framework for cross-over formation. The mammalian SC comprises eight components-synaptonemal complex protein 1-3 (SYCP1-3), synaptonemal complex central element protein 1-3 (SYCE1-3), testis-expressed 12 (TEX12), and six6 opposite strand transcript 1 (SIX6OS1)-arranged in transverse and longitudinal structures. These largely α-helical, coiled-coil proteins undergo heterotypic interactions, coupled with recursive self-assembly of SYCP1, SYCE2-TEX12, and SYCP2-SYCP3, to achieve the vast supramolecular SC structure. Here, we report a novel self-assembly mechanism of the SC central element component SYCE3, identified through multi-angle light scattering and small-angle X-ray scattering (SAXS) experiments. These analyses revealed that SYCE3 adopts a dimeric four-helical bundle structure that acts as the building block for concentration-dependent self-assembly into a series of discrete higher-order oligomers. We observed that this is achieved through staggered lateral interactions between self-assembly surfaces of SYCE3 dimers and through end-on interactions that likely occur through intermolecular domain swapping between dimer folds. These mechanisms are combined to achieve potentially limitless SYCE3 assembly, particularly favoring formation of dodecamers of three laterally associated end-on tetramers. Our findings extend the family of self-assembling proteins within the SC and reveal additional means for structural stabilization of the SC central element.
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Affiliation(s)
- Orla M Dunne
- From the Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
| | - Owen R Davies
- From the Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne NE2 4HH, United Kingdom
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19
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Levasseur MD, Thomas C, Davies OR, Higgins JMG, Madgwick S. Aneuploidy in Oocytes Is Prevented by Sustained CDK1 Activity through Degron Masking in Cyclin B1. Dev Cell 2019; 48:672-684.e5. [PMID: 30745144 PMCID: PMC6416240 DOI: 10.1016/j.devcel.2019.01.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2018] [Revised: 10/22/2018] [Accepted: 12/29/2018] [Indexed: 01/10/2023]
Abstract
Successful mitosis requires that cyclin B1:CDK1 kinase activity remains high until chromosomes are correctly aligned on the mitotic spindle. It has therefore been unclear why, in mammalian oocyte meiosis, cyclin B1 destruction begins before chromosome alignment is complete. Here, we resolve this paradox and show that mouse oocytes exploit an imbalance in the ratio of cyclin B1 to CDK1 to control CDK1 activity; early cyclin B1 destruction reflects the loss of an excess of non-CDK1-bound cyclin B1 in late prometaphase, while CDK1-bound cyclin B1 is destroyed only during metaphase. The ordered destruction of the two forms of cyclin B1 is brought about by a previously unidentified motif that is accessible in free cyclin B1 but masked when cyclin B1 is in complex with CDK1. This protects the CDK1-bound fraction from destruction in prometaphase, ensuring a period of prolonged CDK1 activity sufficient to achieve optimal chromosome alignment and prevent aneuploidy. In mouse oocytes, an excess of cyclin B1 preserves CDK1 activity A motif in non-CDK1-bound cyclin B1 confers preferential APC/C targeting Non-CDK1-bound cyclin B1 is gradually destroyed before CDK1-bound cyclin B1 Prolonged CDK1 activity assists the spindle checkpoint and prevents aneuploidy
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Affiliation(s)
- Mark D Levasseur
- Cell Division Biology Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Christopher Thomas
- Cell Division Biology Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Owen R Davies
- Cell Division Biology Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Jonathan M G Higgins
- Cell Division Biology Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Suzanne Madgwick
- Cell Division Biology Group, Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK.
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20
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Abstract
The reduction in chromosome number during meiosis is essential for the production of haploid germ cells and thereby fertility. To achieve this, homologous chromosomes are first synapsed together by a protein assembly, the synaptonemal complex (SC), which permits genetic exchange by crossing over and the subsequent accurate segregation of homologues. The mammalian SC is formed of a zipper-like array of SYCP1 molecules that bind together homologous chromosomes through self-assembly in the midline that is structurally supported by the central element. The SC central element contains five proteins—SYCE1, SYCE3, SIX6OS1, and SYCE2-TEX12—that permit SYCP1 assembly to extend along the chromosome length to achieve full synapsis. Here, we report the structure of human SYCE1 through solution biophysical methods including multi-angle light scattering and small-angle X-ray scattering. The structural core of SYCE1 is formed by amino acids 25–179, within the N-terminal half of the protein, which mediates SYCE1 dimerization. This α-helical core adopts a curved coiled-coil structure of 20-nm length in which the two chains are arranged in an anti-parallel configuration. This structure is retained within full-length SYCE1, in which long C-termini adopt extended conformations to achieve an elongated molecule of over 50 nm in length. The SYCE1 structure is compatible with it functioning as a physical strut that tethers other components to achieve structural stability of the SC central element.
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Affiliation(s)
- Orla M Dunne
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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21
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Dunce JM, Milburn AE, Gurusaran M, da Cruz I, Sen LT, Benavente R, Davies OR. Structural basis of meiotic telomere attachment to the nuclear envelope by MAJIN-TERB2-TERB1. Nat Commun 2018; 9:5355. [PMID: 30559341 PMCID: PMC6297230 DOI: 10.1038/s41467-018-07794-7] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 11/27/2018] [Indexed: 01/12/2023] Open
Abstract
Meiotic chromosomes undergo rapid prophase movements, which are thought to facilitate the formation of inter-homologue recombination intermediates that underlie synapsis, crossing over and segregation. The meiotic telomere complex (MAJIN, TERB1, TERB2) tethers telomere ends to the nuclear envelope and transmits cytoskeletal forces via the LINC complex to drive these rapid movements. Here, we report the molecular architecture of the meiotic telomere complex through the crystal structure of MAJIN-TERB2, together with light and X-ray scattering studies of wider complexes. The MAJIN-TERB2 2:2 hetero-tetramer binds strongly to DNA and is tethered through long flexible linkers to the inner nuclear membrane and two TRF1-binding 1:1 TERB2-TERB1 complexes. Our complementary structured illumination microscopy studies and biochemical findings reveal a telomere attachment mechanism in which MAJIN-TERB2-TERB1 recruits telomere-bound TRF1, which is then displaced during pachytene, allowing MAJIN-TERB2-TERB1 to bind telomeric DNA and form a mature attachment plate. The meiotic telomere complex (MAJIN, TERB1, TERB2) tethers telomere ends to the nuclear envelope. Here the authors present the crystal structure of human MAJIN-TERB2 and combine biophysical approaches and structured illumination microscopy analysis of mouse meiotic chromosomes to characterize the molecular architecture of the wider MAJIN-TERB2-TERB1 complex and its interactions with TRF1.
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Affiliation(s)
- James M Dunce
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Amy E Milburn
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Manickam Gurusaran
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Irene da Cruz
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, D-97074, Würzburg, Germany
| | - Lee T Sen
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Ricardo Benavente
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, D-97074, Würzburg, Germany.
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
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22
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Dunce JM, Dunne OM, Ratcliff M, Millán C, Madgwick S, Usón I, Davies OR. Structural basis of meiotic chromosome synapsis through SYCP1 self-assembly. Nat Struct Mol Biol 2018; 25:557-569. [PMID: 29915389 DOI: 10.1038/s41594-018-0078-9] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2018] [Accepted: 04/25/2018] [Indexed: 11/10/2022]
Abstract
Meiotic chromosomes adopt unique structures in which linear arrays of chromatin loops are bound together in homologous chromosome pairs by a supramolecular protein assembly, the synaptonemal complex. This three-dimensional scaffold provides the essential structural framework for genetic exchange by crossing over and subsequent homolog segregation. The core architecture of the synaptonemal complex is provided by SYCP1. Here we report the structure and self-assembly mechanism of human SYCP1 through X-ray crystallographic and biophysical studies. SYCP1 has an obligate tetrameric structure in which an N-terminal four-helical bundle bifurcates into two elongated C-terminal dimeric coiled-coils. This building block assembles into a zipper-like lattice through two self-assembly sites. N-terminal sites undergo cooperative head-to-head assembly in the midline, while C-terminal sites interact back to back on the chromosome axis. Our work reveals the underlying molecular structure of the synaptonemal complex in which SYCP1 self-assembly generates a supramolecular lattice that mediates meiotic chromosome synapsis.
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Affiliation(s)
- James M Dunce
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Orla M Dunne
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Matthew Ratcliff
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.,Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Claudia Millán
- Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona, Spain
| | - Suzanne Madgwick
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Isabel Usón
- Crystallographic Methods, Institute of Molecular Biology of Barcelona (IBMB-CSIC), Barcelona, Spain.,ICREA, Institució Catalana de Recerca i Estudis Avançats, Barcelona, Spain
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK.
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23
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Yang Y, Denton H, Davies OR, Smith-Jackson K, Kerr H, Herbert AP, Barlow PN, Pickering MC, Marchbank KJ. An Engineered Complement Factor H Construct for Treatment of C3 Glomerulopathy. J Am Soc Nephrol 2018; 29:1649-1661. [PMID: 29588430 PMCID: PMC6054357 DOI: 10.1681/asn.2017091006] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2017] [Accepted: 02/26/2018] [Indexed: 01/06/2023] Open
Abstract
Background C3 glomerulopathy (C3G) is associated with dysregulation of the alternative pathway of complement activation, and treatment options for C3G remain limited. Complement factor H (FH) is a potent regulator of the alternative pathway and might offer a solution, but the mass and complexity of FH makes generation of full-length FH far from trivial. We previously generated a mini-FH construct, with FH short consensus repeats 1-5 linked to repeats 18-20 (FH1-5^18-20), that was effective in experimental C3G. However, the serum t1/2 of FH1-5^18-20 was significantly shorter than that of serum-purified FH.Methods We introduced the oligomerization domain of human FH-related protein 1 (denoted by R1-2) at the carboxy or amino terminus of human FH1-5^18-20 to generate two homodimeric mini-FH constructs (FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2, respectively) in Chinese hamster ovary cells and tested these constructs using binding, fluid-phase, and erythrocyte lysis assays, followed by experiments in FH-deficient Cfh-/- mice.Results FHR1-2^1-5^18-20 and FH1-5^18-20^R1-2 homodimerized in solution and displayed avid binding profiles on clustered C3b surfaces, particularly FHR1-2^1-5^18-20 Each construct was >10-fold more effective than FH at inhibiting cell surface complement activity in vitro and restricted glomerular basement membrane C3 deposition in vivo significantly better than FH or FH1-5^18-20 FH1-5^18-20^R1-2 had a C3 breakdown fragment binding profile similar to that of FH, a >5-fold increase in serum t1/2 compared with that of FH1-5^18-20, and significantly better retention in the kidney than FH or FH1-5^18-20Conclusions FH1-5^18-20^R1-2 may have utility as a treatment option for C3G or other complement-mediated diseases.
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Affiliation(s)
- Yi Yang
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Harriet Denton
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne, UK
| | - Kate Smith-Jackson
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK
| | - Heather Kerr
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Andrew P Herbert
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | - Paul N Barlow
- Department of Chemistry, Edinburgh University, Edinburgh, UK; and
| | | | - Kevin J Marchbank
- Institute of Cellular Medicine, Newcastle University and National Renal Complement Therapeutics Centre, Royal Victoria Infirmary, Newcastle upon Tyne, UK;
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24
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van der Heijde D, Baraliakos X, Hermann KGA, Landewé RBM, Machado PM, Maksymowych WP, Davies OR, de Peyrecave N, Hoepken B, Bauer L, Nurminen T, Braun J. Limited radiographic progression and sustained reductions in MRI inflammation in patients with axial spondyloarthritis: 4-year imaging outcomes from the RAPID-axSpA phase III randomised trial. Ann Rheum Dis 2018; 77:699-705. [PMID: 29343510 PMCID: PMC5909752 DOI: 10.1136/annrheumdis-2017-212377] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Revised: 12/20/2017] [Accepted: 12/29/2017] [Indexed: 12/17/2022]
Abstract
OBJECTIVES To report 4-year imaging outcomes in the RAPID-axSpA (NCT01087762) study of patients with ankylosing spondylitis (AS) and non-radiographic axial spondyloarthritis (nr-axSpA), treated with certolizumab pegol (CZP). METHODS This phase III, randomised trial was placebo-controlled and double-blind to week 24, dose-blind to week 48 and open-label to week 204. Patients fulfilling the Assessment of Spondyloarthritis International Society (ASAS) axSpA criteria with active disease were stratified (AS/nr-axSpA) according to the modified New York (mNY) criteria at randomisation. Spinal radiographs were assessed using the modified Stoke Ankylosing Spondylitis Spine Score (mSASSS). MRI inflammation used the Spondyloarthritis Research Consortium of Canada (SPARCC) score for sacroiliac joints (SIJ) and the Berlin spinal score (remission defined as SPARCC <2 and Berlin ≤2, respectively). RESULTS MRI improvements from baseline (BL) to week 12 were maintained to week 204 (SPARCC BL: AS=8.5, nr-axSpA=7.5; SPARCC week 204: AS=1.3, nr-axSpA=2.4; Berlin BL: AS=7.4, nr-axSpA=4.4; Berlin week 204: AS=2.6, nr-axSpA=1.9). 66.7% of patients with AS and 69.6% of patients with nr-axSpA with BL SPARCC scores ≥2, and 65.4% of patients with AS and 57.3% of patients with nr-axSpA with BL Berlin score >2, achieved remission at week 204. Mean mSASSS change in AS from BL to week 204 was 0.98 (95% CI 0.34, 1.63); 0.67 (95% CI 0.21,1.13) from BL to week 96; and 0.31 (95% CI 0.02,0.60) from week 96 to week 204. Corresponding nr-axSpA changes were 0.06 (95% CI -0.17,0.28), -0.01 (95% CI -0.19,0.17) and 0.07 (95% CI -0.07,0.20). 4.5% of patients with nr-axSpA fulfilled the mNY criteria at week 204, while 4.3% of patients with AS no longer did so. CONCLUSIONS In patients with CZP-treated axSpA, rapid decreases in spinal and SIJ MRI inflammation were maintained to week 204. Overall, 4-year spinal progression was low, with less progression during years 2-4 than 0-2. Radiographic SIJ grading changes demonstrated limited progression. TRIAL REGISTRATION NUMBER NCT01087762; Post-results.
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Affiliation(s)
| | | | | | - Robert B M Landewé
- Academic Medical Center, Amsterdam and Atrium Medical Center, Heerlen, The Netherlands
| | - Pedro M Machado
- Centre for Rheumatology and MRC Centre for Neuromuscular Diseases, University College London, London, UK
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25
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Syrjänen JL, Heller I, Candelli A, Davies OR, Peterman EJG, Wuite GJL, Pellegrini L. Single-molecule observation of DNA compaction by meiotic protein SYCP3. eLife 2017; 6. [PMID: 28287952 PMCID: PMC5348128 DOI: 10.7554/elife.22582] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2016] [Accepted: 03/04/2017] [Indexed: 12/14/2022] Open
Abstract
In a previous paper (Syrjänen et al., 2014), we reported the first structural characterisation of a synaptonemal complex (SC) protein, SYCP3, which led us to propose a model for its role in chromosome compaction during meiosis. As a component of the SC lateral element, SYCP3 has a critical role in defining the specific chromosome architecture required for correct meiotic progression. In the model, the reported compaction of chromosomal DNA caused by SYCP3 would result from its ability to bridge distant sites on a DNA molecule with the DNA-binding domains located at each end of its strut-like structure. Here, we describe a single-molecule assay based on optical tweezers, fluorescence microscopy and microfluidics that, in combination with bulk biochemical data, provides direct visual evidence for our proposed mechanism of SYCP3-mediated chromosome organisation. DOI:http://dx.doi.org/10.7554/eLife.22582.001
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Affiliation(s)
- Johanna L Syrjänen
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
| | - Iddo Heller
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Andrea Candelli
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, University of Newcastle, Newcastle upon Tyne, United Kingdom
| | - Erwin J G Peterman
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Gijs J L Wuite
- Department of Physics and Astronomy, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands.,LaserLaB, Vrije Universiteit Amsterdam, Amsterdam, The Netherlands
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge, United Kingdom
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26
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Gómez-H L, Felipe-Medina N, Sánchez-Martín M, Davies OR, Ramos I, García-Tuñón I, de Rooij DG, Dereli I, Tóth A, Barbero JL, Benavente R, Llano E, Pendas AM. C14ORF39/SIX6OS1 is a constituent of the synaptonemal complex and is essential for mouse fertility. Nat Commun 2016; 7:13298. [PMID: 27796301 PMCID: PMC5095591 DOI: 10.1038/ncomms13298] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 09/19/2016] [Indexed: 11/16/2022] Open
Abstract
Meiotic recombination generates crossovers between homologous chromosomes that are essential for genome haploidization. The synaptonemal complex is a ‘zipper'-like protein assembly that synapses homologue pairs together and provides the structural framework for processing recombination sites into crossovers. Humans show individual differences in the number of crossovers generated across the genome. Recently, an anonymous gene variant in C14ORF39/SIX6OS1 was identified that influences the recombination rate in humans. Here we show that C14ORF39/SIX6OS1 encodes a component of the central element of the synaptonemal complex. Yeast two-hybrid analysis reveals that SIX6OS1 interacts with the well-established protein synaptonemal complex central element 1 (SYCE1). Mice lacking SIX6OS1 are defective in chromosome synapsis at meiotic prophase I, which provokes an arrest at the pachytene-like stage and results in infertility. In accordance with its role as a modifier of the human recombination rate, SIX6OS1 is essential for the appropriate processing of intermediate recombination nodules before crossover formation. The synaptonemal complex is a meiosis-specific proteinaceous structure that supports homologous chromosome pairs during meiosis. Here, the authors show that SIX6OS1 (of previously unknown function) is part of the synaptonemal complex central element and upon deletion in mice, causes defective chromosome synapsis and infertility.
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Affiliation(s)
- Laura Gómez-H
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain
| | - Natalia Felipe-Medina
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain
| | - Manuel Sánchez-Martín
- Departamento de Medicina, Universidad de Salamanca, 37007 Salamanca, Spain.,Transgenic Facility, Nucleus platform, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Owen R Davies
- Institute for Cell and Molecular Biosciences, Newcastle University, Newcastle upon Tyne NE2 4HH, UK
| | - Isabel Ramos
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain
| | - Ignacio García-Tuñón
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain
| | - Dirk G de Rooij
- Reproductive Biology Group, Division of Developmental Biology, Department of Biology, Faculty of Science, Utrecht University, 3584CM Utrecht, The Netherlands
| | - Ihsan Dereli
- Institute of Physiological Chemistry, Medical Faculty of TU Dresden, Fiedlerstrasse 42, 01307 Dresden, Germany
| | - Attila Tóth
- Institute of Physiological Chemistry, Medical Faculty of TU Dresden, Fiedlerstrasse 42, 01307 Dresden, Germany
| | - José Luis Barbero
- Departamento de Biología Celular y Molecular, Centro de Investigaciones Biológicas (CSIC), Madrid 28040, Spain
| | - Ricardo Benavente
- Department of Cell and Developmental Biology, Biocenter, University of Würzburg, D-97074 Würzburg, Germany
| | - Elena Llano
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain.,Departamento de Fisiología y Farmacología, Universidad de Salamanca, 37007 Salamanca, Spain
| | - Alberto M Pendas
- Instituto de Biología Molecular y Celular del Cáncer (CSIC-Universidad de Salamanca), 37007 Salamanca, Spain
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27
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Carroll B, Maetzel D, Maddocks ODK, Otten G, Ratcliff M, Smith GR, Dunlop EA, Passos JF, Davies OR, Jaenisch R, Tee AR, Sarkar S, Korolchuk VI. Control of TSC2-Rheb signaling axis by arginine regulates mTORC1 activity. eLife 2016; 5:e11058. [PMID: 26742086 PMCID: PMC4764560 DOI: 10.7554/elife.11058] [Citation(s) in RCA: 126] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 12/30/2015] [Indexed: 01/07/2023] Open
Abstract
The mammalian target of rapamycin complex 1 (mTORC1) is the key signaling hub that regulates cellular protein homeostasis, growth, and proliferation in health and disease. As a prerequisite for activation of mTORC1 by hormones and mitogens, there first has to be an available pool of intracellular amino acids. Arginine, an amino acid essential during mammalian embryogenesis and early development is one of the key activators of mTORC1. Herein, we demonstrate that arginine acts independently of its metabolism to allow maximal activation of mTORC1 by growth factors via a mechanism that does not involve regulation of mTORC1 localization to lysosomes. Instead, arginine specifically suppresses lysosomal localization of the TSC complex and interaction with its target small GTPase protein, Rheb. By interfering with TSC-Rheb complex, arginine relieves allosteric inhibition of Rheb by TSC. Arginine cooperates with growth factor signaling which further promotes dissociation of TSC2 from lysosomes and activation of mTORC1. Arginine is the main amino acid sensed by the mTORC1 pathway in several cell types including human embryonic stem cells (hESCs). Dependence on arginine is maintained once hESCs are differentiated to fibroblasts, neurons, and hepatocytes, highlighting the fundamental importance of arginine-sensing to mTORC1 signaling. Together, our data provide evidence that different growth promoting cues cooperate to a greater extent than previously recognized to achieve tight spatial and temporal regulation of mTORC1 signaling.
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Affiliation(s)
- Bernadette Carroll
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Dorothea Maetzel
- Whitehead Institute for Biomedical ResearchMassachusetts Institute of TechnologyCambridgeUnited States
| | | | - Gisela Otten
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Matthew Ratcliff
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Graham R Smith
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Elaine A Dunlop
- Institute of Cancer and GeneticsCardiff UniversityCardiffUnited Kingdom
| | - João F Passos
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Owen R Davies
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
| | - Rudolf Jaenisch
- Whitehead Institute for Biomedical ResearchMassachusetts Institute of TechnologyCambridgeUnited States
| | - Andrew R Tee
- Institute of Cancer and GeneticsCardiff UniversityCardiffUnited Kingdom
| | - Sovan Sarkar
- Institute of Cancer and Genomic Sciences, Institute of Biomedical Research, College of Medical and Dental SciencesUniversity of BirminghamBirminghamUnited Kingdom
| | - Viktor I Korolchuk
- Institute for Cell and Molecular BiosciencesNewcastle UniversityNewcastle upon TyneUnited Kingdom
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28
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Davies OR, Forment JV, Sun M, Belotserkovskaya R, Coates J, Galanty Y, Demir M, Morton CR, Rzechorzek NJ, Jackson SP, Pellegrini L. CtIP tetramer assembly is required for DNA-end resection and repair. Nat Struct Mol Biol 2015; 22:150-157. [PMID: 25558984 PMCID: PMC4564947 DOI: 10.1038/nsmb.2937] [Citation(s) in RCA: 58] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2014] [Accepted: 11/21/2014] [Indexed: 12/20/2022]
Abstract
Mammalian CtIP protein has major roles in DNA double-strand break (DSB) repair. Although it is well established that CtIP promotes DNA-end resection in preparation for homology-dependent DSB repair, the molecular basis for this function has remained unknown. Here we show by biophysical and X-ray crystallographic analyses that the N-terminal domain of human CtIP exists as a stable homotetramer. Tetramerization results from interlocking interactions between the N-terminal extensions of CtIP's coiled-coil region, which lead to a 'dimer-of-dimers' architecture. Through interrogation of the CtIP structure, we identify a point mutation that abolishes tetramerization of the N-terminal domain while preserving dimerization in vitro. Notably, we establish that this mutation abrogates CtIP oligomer assembly in cells, thus leading to strong defects in DNA-end resection and gene conversion. These findings indicate that the CtIP tetramer architecture described here is essential for effective DSB repair by homologous recombination.
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Affiliation(s)
- Owen R. Davies
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Josep V. Forment
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
- The Wellcome Trust Sanger Institute, Hinxton, UK
| | - Meidai Sun
- Department of Biochemistry, University of Cambridge, Cambridge, UK
| | - Rimma Belotserkovskaya
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
| | - Julia Coates
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
| | - Yaron Galanty
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
| | - Mukerrem Demir
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
| | | | | | - Stephen P. Jackson
- Department of Biochemistry, University of Cambridge, Cambridge, UK
- The Gurdon Institute, University of Cambridge, Cambridge, UK
- The Wellcome Trust Sanger Institute, Hinxton, UK
| | - Luca Pellegrini
- Department of Biochemistry, University of Cambridge, Cambridge, UK
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Smolen JS, Emery P, Ferraccioli GF, Samborski W, Berenbaum F, Davies OR, Koetse W, Purcaru O, Bennett B, Burkhardt H. Certolizumab pegol in rheumatoid arthritis patients with low to moderate activity: the CERTAIN double-blind, randomised, placebo-controlled trial. Ann Rheum Dis 2014; 74:843-50. [PMID: 24431394 PMCID: PMC4392224 DOI: 10.1136/annrheumdis-2013-204632] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2013] [Accepted: 12/14/2013] [Indexed: 12/29/2022]
Abstract
Objectives This 52-week, randomised, double-blind phase IIIb study assessed efficacy and safety of certolizumab pegol (CZP) as add-on therapy to non-biologic disease-modifying antirheumatic drugs (DMARDs) in rheumatoid arthritis (RA) patients with low to moderate disease activity, and stopping therapy in patients in sustained remission. Methods Patients were randomised 1:1 to CZP (400 mg at weeks 0, 2 and 4, then 200 mg every 2 weeks) or placebo (every 2 weeks) plus current non-biologic DMARDs. At week 24, patients who achieved the primary endpoint of Clinical Disease Activity Index (CDAI) remission at both weeks 20 and 24 stopped study treatment and continued in the study until week 52. Results Of 194 patients (CZP=96; placebo=98), >90% had moderate disease activity at baseline. Significantly more CZP patients met the primary endpoint than placebo patients (week 20 and 24 CDAI remission rates: 18.8% vs 6.1%; p≤0.05). At week 24, 63.0% vs 29.7% of CZP versus placebo patients (p<0.001) achieved LDA. Disease activity score (ESR) based on 28-joint count and Simplified Disease Activity Index remission rates were also significantly higher with CZP versus placebo (19.8% vs 3.1%; p≤0.01 and 14.6% vs 4.1%; p≤0.05). CZP patients reported improvements in physical function versus placebo (mean Health Assessment Questionnaire-Disability-Index change from baseline: CZP, −0.25 vs placebo, −0.03; p≤0.01). During the period following withdrawal of CZP or placebo, only 3/17 prior CZP patients and 2/6 prior placebo patients maintained CDAI remission until week 52, but CZP reinstitution allowed renewed improvement. Adverse and serious adverse event rates were comparable between CZP and placebo groups. Conclusions Addition of CZP to non-biologic DMARDs is an effective treatment in RA patients with predominantly moderate disease activity, allowing low-disease activity or remission to be reached in a majority of the patients. However, the data suggest that CZP cannot be withdrawn in patients achieving remission. Trial registration number NCT00674362.
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Affiliation(s)
- J S Smolen
- Division of Rheumatology, Department of Medicine 3, Medical University of Vienna, and 2nd Department of Medicine, Hietzing Hospital, Vienna, Austria
| | - P Emery
- Leeds Institute of Rheumatic and Musculoskeletal Medicine, University of Leeds, Chapel Allerton Hospital, Leeds, UK NIHR Leeds Musculoskeletal Biomedical Research Unit, Leeds Teaching Hospitals NHS Trust, Leeds, UK
| | - G F Ferraccioli
- Institute of Rheumatology and Affine Sciences, Catholic University of the Sacred Heart, Rome, Italy
| | - W Samborski
- University of Medical Sciences, Poznan, Poland
| | - F Berenbaum
- Department of Rheumatology, DHU i2B, INSERM UMR-S938, Pierre & Marie Curie University Paris 06, Saint-Antoine hospital, AP-HP, Paris, France
| | | | - W Koetse
- UCB Pharma, Raleigh, North Carolina, USA
| | | | | | - H Burkhardt
- CIRI/Division of Rheumatology and Fraunhofer TMP, Goethe-University, Frankfurt am Main, Germany
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Davies OR, Maman JD, Pellegrini L. Structural analysis of the human SYCE2-TEX12 complex provides molecular insights into synaptonemal complex assembly. Open Biol 2013; 2:120099. [PMID: 22870393 PMCID: PMC3411106 DOI: 10.1098/rsob.120099] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2012] [Accepted: 06/26/2012] [Indexed: 11/12/2022] Open
Abstract
The successful completion of meiosis is essential for all sexually reproducing organisms. The synaptonemal complex (SC) is a large proteinaceous structure that holds together homologous chromosomes during meiosis, providing the structural framework for meiotic recombination and crossover formation. Errors in SC formation are associated with infertility, recurrent miscarriage and aneuploidy. The current lack of molecular information about the dynamic process of SC assembly severely restricts our understanding of its function in meiosis. Here, we provide the first biochemical and structural analysis of an SC protein component and propose a structural basis for its function in SC assembly. We show that human SC proteins SYCE2 and TEX12 form a highly stable, constitutive complex, and define the regions responsible for their homotypic and heterotypic interactions. Biophysical analysis reveals that the SYCE2–TEX12 complex is an equimolar hetero-octamer, formed from the association of an SYCE2 tetramer and two TEX12 dimers. Electron microscopy shows that biochemically reconstituted SYCE2–TEX12 complexes assemble spontaneously into filamentous structures that resemble the known physical features of the SC central element (CE). Our findings can be combined with existing biological data in a model of chromosome synapsis driven by growth of SYCE2–TEX12 higher-order structures within the CE of the SC.
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Affiliation(s)
- Owen R Davies
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Old Addenbrookes Site, Cambridge CB2 1GA, UK.
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Weinblatt ME, Fleischmann R, Huizinga TWJ, Emery P, Pope J, Massarotti EM, van Vollenhoven RF, Wollenhaupt J, Bingham CO, Duncan B, Goel N, Davies OR, Dougados M. Efficacy and safety of certolizumab pegol in a broad population of patients with active rheumatoid arthritis: results from the REALISTIC phase IIIb study. Rheumatology (Oxford) 2012; 51:2204-14. [PMID: 22923753 DOI: 10.1093/rheumatology/kes150] [Citation(s) in RCA: 93] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
OBJECTIVE To investigate the efficacy and safety of certolizumab pegol (CZP) in a broad population of patients with active RA. METHODS In this 12-week, double-blind period of the phase IIIb trial, RA patients with inadequate response to at least one DMARD were randomized 4:1 to CZP (400 mg at weeks 0, 2 and 4, followed by 200 mg every 2 weeks) or placebo (every 2 weeks) plus current therapy stratified by previous TNF inhibitor use, concomitant methotrexate use and disease duration (<2 vs ≥2 years). The primary outcome was ACR20 response rate at week 12. RESULTS Of 1063 patients (CZP = 851; placebo = 212), 37.6% had previous TNF inhibitor use. Baseline mean HAQ Disability Index (HAQ-DI) and DAS 28-joint assessment-ESR [DAS28(ESR)] values were 1.5 and 6.4 in the CZP group, and 1.6 and 6.4 in the placebo group, respectively. The primary endpoint was significant (week 12 ACR20, CZP vs placebo: 51.1 vs 25.9%; P < 0.001); differences were noted at week 2 (31.8 vs 8.5%; P < 0.001). HAQ-DI and DAS28(ESR) change from baseline and ACR50 were significant from week 2. Week 12 ACR20 responses were similar across CZP patient subgroups regardless of concomitant DMARD use at baseline. Adverse and serious adverse events were comparable between CZP and placebo, with no new safety signals. CONCLUSION CZP was associated with rapid and consistent clinical responses and improved physical function in a diverse group of RA patients, irrespective of concomitant or previous therapy. TRIAL REGISTRATION ClinicalTrials.gov, http://clinicaltrials.gov/, NCT00717236.
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Affiliation(s)
- Michael E Weinblatt
- Harvard Medical School, Division of Rheumatology, Immunology and Allergy, Brigham and Women's Hospital, 75 Francis Street, Boston, MA 02115, USA.
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Baxendale A, van Hooff P, Durrant LG, Spendlove I, Howdle SM, Woods HM, Whitaker MJ, Davies OR, Naylor A, Lewis AL, Illum L. Single shot tetanus vaccine manufactured by a supercritical fluid encapsulation technology. Int J Pharm 2011; 413:147-54. [PMID: 21554938 DOI: 10.1016/j.ijpharm.2011.04.053] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Revised: 04/17/2011] [Accepted: 04/19/2011] [Indexed: 01/26/2023]
Abstract
Single shot vaccines of tetanus toxoid (TT) were manufactured using the NanoMix process - a low temperature solvent free encapsulation technology using supercritical fluids. The formulations were injected into mice, and compared to multiple injections of a commercially available alum adsorbed TT vaccine. After 5 months the antibody titres were found to be similar for both the alum adsorbed and microparticle formulations, demonstrating for the first time the potential of formulating antigens in PLA microparticles using the supercritical fluid (NanoMix) technique to produce single shot vaccines. The results are likely to be due to the maintenance of toxoid bioactivity and some degree of sustained release of the encapsulated antigens, resulting in repeated stimulation of antigen presenting cells eliminating the need for multiple immunisations. This demonstrates the potential of this supercritical fluid processing technique to reduce the need for booster doses in a vaccine regimen.
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Affiliation(s)
- Aj Baxendale
- Critical Pharmaceuticals Ltd., BioCity Nottingham, Pennyfoot Street, Nottingham NG1 1GF, UK
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Abstract
BubR1 is essential for the mitotic checkpoint that prevents aneuploidy in cellular progeny by triggering anaphase delay in response to kinetochores incorrectly/not attached to the mitotic spindle. Here, we define the molecular architecture of the functionally significant N-terminal region of human BubR1 and present the 1.8 A crystal structure of its tetratricopeptide repeat (TPR) domain. The structure reveals divergence from the classical TPR fold and is highly similar to the TPR domain of budding yeast Bub1. Shared distinctive features include a disordered loop insertion, a 3(10)-helix, a tight turn involving glycine positive Phi angles, and noncanonical packing of and between the TPR motifs. We also define the molecular determinants of the interaction between BubR1 and kinetochore protein Blinkin. We identify a shallow groove on the concave surface of the BubR1 TPR domain that forms multiple discrete and potentially cooperative interactions with Blinkin. Finally, we present evidence for a direct interaction between BubR1 and Bub1 mediated by regions C-terminal to their TPR domains. This interaction provides a mechanism for Bub1-dependent kinetochore recruitment of BubR1. We thus present novel molecular insights into the structure of BubR1 and its interactions at the kinetochore-microtubule interface. Our studies pave the way for future structure-directed engineering aimed at dissecting the roles of kinetochore-bound and other pools of BubR1 in vivo.
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Affiliation(s)
- Sheena D'Arcy
- Department of Biochemistry, University of Cambridge, Cambridge CB2 1GA, United Kingdom
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Davies OR, Junker K, Jansen R, Crowe TM, Boomker J. Age- and sex-based variation in helminth infection of helmeted guineafowl (Numida meleagris) with comments on Swainson's spurfowl (Pternistis swainsonii) and Orange River francolin (Scleroptila levaillantoides). ACTA ACUST UNITED AC 2008. [DOI: 10.3957/0379-4369-38.2.163] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022]
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Abstract
Novel macroporous and surface functionalized polymeric microparticles were prepared using a modified emulsion technique. The microparticles were able to surface load DNA and have a range of potential applications in drug delivery of biologics and tissue engineering.
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Affiliation(s)
- Owen R Davies
- School of Pharmacy, University of Nottingham, University Park, Nottingham, UKNG7 2RD.
| | - Maria Marlow
- AstraZeneca R&D Charnwood, Bakewell Road, Loughborough, UKLE12 5RH
| | - Snow Stolnik
- School of Pharmacy, University of Nottingham, University Park, Nottingham, UKNG7 2RD.
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Davies OR, Head L, Armitage D, Pearson EA, Davies MC, Marlow M, Stolnik S. Surface modification of microspheres with steric stabilizing and cationic polymers for gene delivery. Langmuir 2008; 24:7138-7146. [PMID: 18558783 DOI: 10.1021/la703735n] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
In this paper, we describe surface modification of poly( D,L-lactide- co-glycolide) (PLG) microspheres, intended for DNA vaccine application, with two functionalities: a steric stabilizing component, provided by poly(vinyl alcohol) (PVA) and a cationic component, aimed at subsequent DNA surface loading. The cationic functionality arises from polycations, such as PEI, poly( L-lysine), trimethyl chitosan, and (dimethylamino)ethyl methacrylate, introduced into the water phase of classical oil-in-water (o/w) solvent evaporation method of PLG microsphere fabrication. By systematic evaluation of production variables, a system was produced with balanced properties in terms of microsphere size appropriate for uptake by antigen presenting (e.g., dendritic) cells, colloidal stability, and relatively high DNA loading. The polycation (PEI) molecular weight and preparation concentration were both found to increase the surface polycation content and DNA binding capacity; however, they lead to an increased tendency for aggregation, particularly when the microsphere size was decreased. DNA loading of almost 100% efficiency was achieved under optimized conditions in physiologically acceptable buffers, resulting in a surface DNA loading appropriate for vaccine purposes. A further increase in surface DNA loading was however associated with an increase in the particles negative potential, indicating the surface presence of DNA charges not neutralized by the polycation and hence potentially not protected from in vivo enzymatic degradation. The internalization of surface-loaded DNA into the target cells was confirmed by monitoring fluorescent DNA after the microspheres were endocytosed by the cells in culture.
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Affiliation(s)
- Owen R Davies
- School of Pharmacy, University of Nottingham, University Park, Nottingham NG7 2RD, United Kingdom
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Davies OR, Lewis AL, Whitaker MJ, Tai H, Shakesheff KM, Howdle SM. Applications of supercritical CO2 in the fabrication of polymer systems for drug delivery and tissue engineering. Adv Drug Deliv Rev 2008; 60:373-87. [PMID: 18069079 DOI: 10.1016/j.addr.2006.12.001] [Citation(s) in RCA: 227] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2006] [Accepted: 12/14/2006] [Indexed: 11/26/2022]
Abstract
Supercritical CO(2) has the potential to be an excellent environment within which controlled release polymers and dry composites may be formed. The low temperature and dry conditions within the fluid offer obvious advantages in the processing of water, solvent or heat labile molecules. The low viscosity and high diffusivity of scCO(2) offer the possibility of novel processing routes for polymer drug composites, but there are still technical challenges to overcome. Moreover, the low solubility of most drug molecules in scCO(2) presents both challenges and advantages. This review explores the current methods that use high pressure and scCO(2) for the production of drug delivery systems and the more specialized application of the fluid in the formation of highly porous tissue engineering scaffolds.
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Li Y, Chirgadze DY, Bolanos-Garcia VM, Sibanda BL, Davies OR, Ahnesorg P, Jackson SP, Blundell TL. Crystal structure of human XLF/Cernunnos reveals unexpected differences from XRCC4 with implications for NHEJ. EMBO J 2007; 27:290-300. [PMID: 18046455 PMCID: PMC2104711 DOI: 10.1038/sj.emboj.7601942] [Citation(s) in RCA: 98] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2007] [Accepted: 11/02/2007] [Indexed: 11/30/2022] Open
Abstract
The recently characterised 299-residue human XLF/Cernunnos protein plays a crucial role in DNA repair by non-homologous end joining (NHEJ) and interacts with the XRCC4–DNA Ligase IV complex. Here, we report the crystal structure of the XLF (1–233) homodimer at 2.3 Å resolution, confirming the predicted structural similarity to XRCC4. The XLF coiled-coil, however, is shorter than that of XRCC4 and undergoes an unexpected reverse in direction giving rise to a short distorted four helical bundle and a C-terminal helical structure wedged between the coiled-coil and head domain. The existence of a dimer as the major species is confirmed by size-exclusion chromatography, analytical ultracentrifugation, small-angle X-ray scattering and other biophysical methods. We show that the XLF structure is not easily compatible with a proposed XRCC4:XLF heterodimer. However, we demonstrate interactions between dimers of XLF and XRCC4 by surface plasmon resonance and analyse these in terms of surface properties, amino-acid conservation and mutations in immunodeficient patients. Our data are most consistent with head-to-head interactions in a 2:2:1 XRCC4:XLF:Ligase IV complex.
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Affiliation(s)
- Yi Li
- Department of Biochemistry, University of Cambridge, Cambridge, UK.
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Shivji MKK, Davies OR, Savill JM, Bates DL, Pellegrini L, Venkitaraman AR. A region of human BRCA2 containing multiple BRC repeats promotes RAD51-mediated strand exchange. Nucleic Acids Res 2006; 34:4000-11. [PMID: 16914443 PMCID: PMC1557805 DOI: 10.1093/nar/gkl505] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Human BRCA2, a breast and ovarian cancer suppressor, binds to the DNA recombinase RAD51 through eight conserved BRC repeats, motifs of ∼30 residues, dispersed across a large region of the protein. BRCA2 is essential for homologous recombination in vivo, but isolated BRC repeat peptides can prevent the assembly of RAD51 into active nucleoprotein filaments in vitro, suggesting a model in which BRCA2 sequesters RAD51 in undamaged cells, and promotes recombinase function after DNA damage. How BRCA2 might fulfill these dual functions is unclear. We have purified a fragment of human BRCA2 (BRCA2BRC1–8) with 1127 residues spanning all 8 BRC repeats but excluding the C-terminal DNA-binding domain (BRCA2CTD). BRCA2BRC1–8 binds RAD51 nucleoprotein filaments in a ternary complex, indicating it may organize RAD51 on DNA. Human RAD51 is relatively ineffective in vitro at strand exchange between homologous DNA molecules unless non-physiological ions like NH4+ are present. In an ionic milieu more typical of the mammalian nucleus, BRCA2BRCI–8 stimulates RAD51-mediated strand exchange, suggesting it may be an essential co-factor in vivo. Thus, the human BRC repeats, embedded within their surronding sequences as an eight-repeat unit, mediate homologous recombination independent of the BRCA2CTD through a previously unrecognized role in control of RAD51 activity.
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Affiliation(s)
| | - Owen R. Davies
- Department of Biochemistry, University of CambridgeTennis Court Road, Cambridge CB2 1GA, UK
| | | | | | - Luca Pellegrini
- Department of Biochemistry, University of CambridgeTennis Court Road, Cambridge CB2 1GA, UK
| | - Ashok R. Venkitaraman
- To whom correspondence should be addressed. Ashok R. Venkitaraman, Hutchison/MRC Research Centre, University of Cambridge, Hills Road, Cambridge CB2 2XZ, UK. Tel: +44 1223 336901; Fax: +44 1223 763374;
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Doré AS, Furnham N, Davies OR, Sibanda BL, Chirgadze DY, Jackson SP, Pellegrini L, Blundell TL. Structure of an Xrcc4-DNA ligase IV yeast ortholog complex reveals a novel BRCT interaction mode. DNA Repair (Amst) 2006; 5:362-8. [PMID: 16388993 DOI: 10.1016/j.dnarep.2005.11.004] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2005] [Revised: 11/10/2005] [Accepted: 11/10/2005] [Indexed: 11/26/2022]
Abstract
DNA ligase IV catalyses the final ligation step in the non-homologous end-joining (NHEJ) DNA repair pathway and requires interaction of the ligase with the Xrcc4 'genome-guardian', an essential NHEJ factor. Here we report the 3.9 A crystal structure of the Saccharomyces cerevisiae Xrcc4 ortholog ligase interacting factor 1 (Lif1p) complexed with the C-terminal BRCT domains of DNA ligase IV (Lig4p). The structure reveals a novel mode of protein recognition by a tandem BRCT repeat, and in addition provides a molecular basis for a human LIG4 syndrome clinical condition.
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Affiliation(s)
- Andrew S Doré
- Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
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Whitaker MJ, Hao J, Davies OR, Serhatkulu G, Stolnik-Trenkic S, Howdle SM, Shakesheff KM. The production of protein-loaded microparticles by supercritical fluid enhanced mixing and spraying. J Control Release 2005; 101:85-92. [PMID: 15588896 DOI: 10.1016/j.jconrel.2004.07.017] [Citation(s) in RCA: 84] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2004] [Accepted: 07/12/2004] [Indexed: 11/26/2022]
Abstract
In this study, we use supercritical carbon dioxide as a processing medium for the fabrication of poly(DL-lactic acid) P(DLLA) microparticles that encapsulate a protein material. We have previously demonstrated that this polymer and a dry powder of a protein can be mixed under supercritical carbon dioxide conditions (above 31.1 degrees C and 73.8 bar) and that the protein component retains its biological activity. In this paper, we progress the work to demonstrate that the plasticized polymer and dry powder protein mixture can be sprayed to form solid polymer particles that encapsulate the protein. Particle size range is between 10 and 300 microm after spraying. Ribonuclease A and lysozyme were encapsulated in the polymer without significant loss of enzymatic activity. Biological assays of insulin and calcitonin confirm retention of activity after fabrication of the microparticles and release of the peptides/proteins.
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Abstract
A vaccine against the human hookworm Necator americanus is urgently required to reduce hookworm-induced morbidity in endemic areas. In the present study, recombinant hookworm calreticulin, a nominated vaccine candidate, has been tested in mice. Mice given calreticulin had 43-49% fewer worms in their lungs, compared to non-vaccinated controls, following challenge infection with infective hookworm larvae. These levels of protection were achieved in the absence of adjuvant following intraperitoneal administration of three doses of 15 microg antigen. Antigen was also encapsulated in PLG microparticles. Encapsulated calreticulin elicited higher levels of anti-calreticulin IgG1 than free antigen but failed to induce protective immunity. The protection induced by free calreticulin was associated with low levels of serum IgE and moderate lung eosinophilia whilst administration of calreticulin-loaded microparticles was associated with high levels of serum IgE and higher lung eosinophil activity, suggesting that the classical Th2 phenotype may not always be associated with protective immunity, albeit in experimental necatoriasis.
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Affiliation(s)
- J A Winter
- University of Nottingham, School of Pharmacy, University Park, Nottingham, NG7 2RD, UK
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Garrett SW, Davies OR, Milroy DA, Wood PJ, Pouton CW, Threadgill MD. Synthesis and characterisation of polyamine-poly(ethylene glycol) constructs for DNA binding and gene delivery. Bioorg Med Chem 2000; 8:1779-97. [PMID: 10976527 DOI: 10.1016/s0968-0896(00)00113-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Improved non-viral vector systems are needed for efficient delivery of DNA to target cell nuclei in gene therapy. A series of linear polyamine poly(ethylene glycol) (PEG) constructs has been synthesised by reaction of appropriately Boc-protected thermine derivatives with omega-methoxyPEG oxiranylmethyl ethers. Constructs carrying 1-3 MeOPEG units and 0, 2 or 4 N-methyl groups have been prepared by this method. H2N(CH2)3NBoc(CH2)3NBoc(CH2)3NHBoc was prepared efficiently by mono-trifluoroacetylation of thermine, attachment of Boc and removal of the trifluoroacetyl group in one pot. A similar process gave H2N(CH2)3NBoc(CH2)3NBoc(CH2)3NH2. BocMeN(CH2)3NHMe was alkylated by 1,3-dibromopropane to give BocMeN(CH2)3NMe(CH2)3NMe(CH2)3NMeBoc. A cyanoethylation/reduction sequence extended H2N(CH2)3NBoc(CH2)3NBoc(CH2)3NH2 to give H2N(CH2)3NBoc(CH2)3NBoc(CH2)3NBoc(CH2)3NBoc(CH2) 3NH2, which was converted to its mono- and di-MeOPEG550 derivatives. Deprotection gave the linear polyamine MeOPEG constructs. A branched triamine-poly(ethylene glycol) construct was prepared by acylation of (BocHN(CH2)3)2N(CH2)3NH2 with omega-methoxyPEG 550 chloroformate, followed by deprotection. A cyanoethylation/reduction/protection sequence from (H2N(CH2)3)2 N(CH2)3NHBoc gave a protected pentamine. Alkylation with Br(CH2)5CONH(CH2)2NHBoc, deprotection, acylation with MeOPEG chloroformate and deprotection gave a pentamine MeOPEG construct in which the MeOPEG is attached through a linker to the central amine. The linear hexamine construct carrying MeOPEG550 at only one terminus was the most effective DNA-interactive member of the two series in an ethidium displacement assay and was effective in delivering a reporter gene to RIF-1 tumours.
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Affiliation(s)
- S W Garrett
- Department of Pharmacy and Pharmacology, University of Bath, Claverton Down, UK
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