DOCSLIB.ORG

Kinetochore-Driven Control of Meiotic DNA Break Formation and Recombination at Centromere-Proximal Regions

Total Page：16

File Type：pdf, Size：1020Kb

Download full-text PDF Read full-text
Kinetochore-Driven Control of Meiotic DNA Break Formation and Recombination at Centromere-Proximal Regions Kinetochore-driven control of meiotic DNA break formation and recombination at centromere-proximal regions Inaugural-Dissertation zur Erlangung des Doktorgrades Dr. rer. nat. der Fakultät für Biologie an der Universität Duisburg-Essen vorgelegt von Lisa-Marie Kuhl aus Witten durchgeführt am Max Planck Institut für molekulare Physiologie Abteilung für mechanistische Zellbiologie Februar 2018 Die der vorliegenden Arbeit zugrunde liegenden Experimente wurden am Max Planck Institut für molekulare Physiologie in der Abteilung für mechanistische Zellbiologie durchgeführt. 1. Gutachter: Prof. Dr. Andrea Musacchio 2. Gutachter: Prof. Dr. Stefan Westermann Vorsitzender des Prüfungsausschusses: Prof. Dr. Hemmo Meyer Tag der mündlichen Prüfung: 13. April 2018 Diese Dissertation wird über DuEPublico, dem Dokumenten- und Publikationsserver der Universität Duisburg-Essen, zur Verfügung gestellt und liegt auch als Print-Version vor. DOI: 10.17185/duepublico/46030 URN: urn:nbn:de:hbz:464-20190418-114218-2 Alle Rechte vorbehalten. In the context of this doctoral work, the following article was published: - Vincenten, N., Kuhl, LM., Lam, I., Oke, A., Kerr, ARW., Hochwagen, A., Fung, J., Keeney, S., Vader, G., Marston, AL. (2015). The kinetochore prevents centromere- proximal crossover recombination during meiosis. Elife 4: e10850 Index I Content Content………………………………..………………………………………………...........I List of Figures ........................................................................................................... V List of Tables .......................................................................................................... VIII List of Abbreviations ............................................................................................... IX 1 Introduction .......................................................................................................... 1 1.1 An overview of meiosis: Similarities and differences from mitosis .......... 1 1.1.1 Cell cycle phases ....................................................................................... 3 1.1.2 G1 phase .................................................................................................... 4 1.1.3 S phase ...................................................................................................... 4 1.1.4 G2/ prophase I ............................................................................................ 5 1.1.5 Meiosis I and meiosis II .............................................................................. 8 1.1.6 Cyclin dependent kinases and Dbf4/ Cdc7 kinase ................................... 10 1.1.7 Checkpoints .............................................................................................. 11 1.2 An overview of meiotic recombination in S. cerevisiae ........................... 12 1.2.1 Meiotic recombination: From DSB formation to inter-homolog repair ........ 12 1.2.2 Non-random genome-wide distribution of meiotic recombination events .. 15 1.3 Centromeric and pericentromeric regions ................................................ 18 1.3.1 Centromeres and pericentromeres are cold regions for meiotic DSB formation and recombination .............................................................................. 19 1.3.2 Centromere- and pericentromere-associated proteins ............................. 22 1.4 The kinetochore: Composition and function in S. cerevisiae .................. 26 1.4.1 The Ctf19 complex ................................................................................... 29 1.5 Objectives ..................................................................................................... 32 2 Materials and Methods ....................................................................................... 34 2.1 Materials ........................................................................................................ 34 2.1.1 Chemicals and Reagents ......................................................................... 34 2.1.2 Enzymes and commercially prepared master mixes ................................ 35 2.1.3 Kits ........................................................................................................... 36 2.1.4. Laboratory instruments and supplies ....................................................... 37 2.1.5 Antibodies ................................................................................................. 39 2.1.6 Buffers and solutions. ............................................................................... 40 Index II 2.1.7 Media. ....................................................................................................... 44 2.1.8 Yeast strains. ............................................................................................ 45 2.1.9 Synthetic oligonucleotides. ....................................................................... 45 2.1.10 Plasmids. ............................................................................................... 45 2.1.11 Online Tools. .......................................................................................... 46 2.1.12 Software ................................................................................................ 46 2.2 Methods ........................................................................................................ 48 2.2.1 Growth and maintenance of S. cerevisiae ................................................ 48 2.2.1.1 Growth conditions of yeast strains ...................................................... 48 2.2.1.2 Meiotic cell cycle synchronization ....................................................... 48 2.2.1.3 Yeast stock preservation ..................................................................... 49 2.2.1.4 Yeast cell growth assay ...................................................................... 49 2.2.2 Construction of yeast strains .................................................................... 49 2.2.2.1 Competent yeast cells ......................................................................... 49 2.2.2.2 Yeast transformation ........................................................................... 50 2.2.2.3 Diploid yeast strain creation ................................................................ 50 2.2.3 Methods of DNA analysis ......................................................................... 51 2.2.3.1 Polymerase Chain Reaction (PCR) ..................................................... 51 2.2.3.2 Agarose gel electrophoresis ................................................................ 52 2.2.3.3 DNA extraction and purification ........................................................... 52 2.2.3.4 Gibson assembly ................................................................................. 52 2.2.3.5 Transformation of plasmid DNA into competent bacteria cells ........... 53 2.2.3.6 Colony PCR ........................................................................................ 53 2.2.3.7 Isolation of plasmid from Escherichia coli ........................................... 53 2.2.3.8 Determination of DNA concentration ................................................... 53 2.2.3.9 Sequencing ......................................................................................... 54 2.2.3.10 Real time quantitative PCR (qPCR) .................................................. 54 2.2.3.11 Southern Blot .................................................................................... 55 2.2.3.11.2 Digestion of genomic DNA ......................................................... 56 2.2.3.11.3 Southern blotting procedure ....................................................... 57 2.2.3.11.4 Southern blot hybridization and washing .................................... 57 2.2.3.11.5 Phosphorimaging ........................................................................ 58 2.2.3.12 Genomic DNA preparation from yeast for PCR-based genotyping ... 58 2.2.3.13 Analysis of the meiotic program by flow cytometry ........................... 59 Index III 2.2.4 Methods of protein analysis ...................................................................... 59 2.2.4.1 Western blot ........................................................................................ 59 2.2.4.2 Yeast whole cell extract for Western blotting using trichloroacetic acid ........................................................................................................................ 59 2.2.4.4 Western blotting procedure ................................................................. 61 2.2.4.5 Chromatin immunoprecipitation .......................................................... 62 2.2.4.6 Co-Immunoprecipitation ...................................................................... 63 2.2.5 Meiotic recombination, DNA double-strand breaks and spore analyses ... 64 2.2.5.1 Live cell reporter assay ....................................................................... 64 2.2.5.2 Sporulation efficiency and spore viability ............................................ 65 3 Results ................................................................................................................ 67 3.1 The Ctf19-C plays a role in controlling meiotic homologous recombination at pericentromeres ..................................................................... 67 3.2 The Ctf19-C minimizes meiotic DSB formation at pericentromeres ....... 72 3.3 CEN1-proximal DSB formation is reduced by the Ctf19-C
Load more

Recommended publications
  • PDW CV March 2014
    Curriculum Vitae Dr. ir. Peter De Wulf Contact information European Institute of Oncology Department of Experimental Oncology Via Adamello 16 20139 Milan, Italy E-mail: [email protected] Tel: (++39) 0294375036 Fax: (++39) 0294375990 Position 08/2005 - present Principal Investigator Director Kinetochore and Chromosome Segregation Research Unit Department of Experimental Oncology European Institute of Oncology Milan, Italy Education and training 11/1999 - 06/2005 Post-Doctoral Research in Yeast Kinetochore Biology Department of Biology Massachusetts Institute of Technology 77 Massachusetts Avenue 02139 Cambridge (MA), USA Mentor: Prof. Dr. Peter K. Sorger (now at Harvard Medical School, Department of Systems Biology) 07/1996 - 10/1999 Post-Doctoral Research in Bacterial Two-Component Signal Transduction Department of Microbiology and Molecular Genetics Harvard Medical School 210 Longwood Avenue 02115 Boston (MA), USA Mentor: Prof. Dr. Edmund C.C. Lin (deceased) 04-20/07/1999 Course in Protein Purification and Characterization Cold Spring Harbor Laboratory. Cold Spring Harbor (NY), USA Instructors: Dr. Richard Burgess, Dr. Albert Courey, Dr. Sue-Hwa Lin, Dr. Sheenah Mische 06-20/06/1997 Course in Advanced Bacterial Genetics Cold Spring Harbor Laboratory. Cold Spring Harbor (NY), USA Instructors: Dr. Bonnie Bassler, Dr. Colin Manoil, Dr. James Slauch 06/1995 - 06/1996 Training in Yeast Cell Biology Department of Applied Biochemistry University of Milan via Celoria 26 20133 Milan, Italy Mentor: Prof. Dr. Lilia Alberghina (now at the University of Milan-Bicocca, Department of Biotechnology and Biosciences) 1 01/1992-05/1995 Ph.D. in Industrial Microbiology and Biocatalysis Department of Biochemical and Microbial Technology School of Bioengineering University of Ghent Coupure Links 653 B-9000 Ghent, Belgium Mentor: Prof.
    [Show full text]
  • Molecular Determinants of the Ska-Ndc80 Interaction and Their
    RESEARCH ARTICLE Molecular determinants of the Ska-Ndc80 interaction and their influence on microtubule tracking and force-coupling Pim J Huis in ’t Veld1†, Vladimir A Volkov2†, Isabelle D Stender1, Andrea Musacchio1,3*, Marileen Dogterom2* 1Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany; 2Department of Bionanoscience, Faculty of Applied Sciences, Delft University of Technology, Delft, Netherlands; 3Centre for Medical Biotechnology, Faculty of Biology, University Duisburg, Essen, Germany Abstract Errorless chromosome segregation requires load-bearing attachments of the plus ends of spindle microtubules to chromosome structures named kinetochores. How these end-on kinetochore attachments are established following initial lateral contacts with the microtubule lattice is poorly understood. Two microtubule-binding complexes, the Ndc80 and Ska complexes, are important for efficient end-on coupling and may function as a unit in this process, but precise conditions for their interaction are unknown. Here, we report that the Ska-Ndc80 interaction is phosphorylation-dependent and does not require microtubules, applied force, or several previously identified functional determinants including the Ndc80-loop and the Ndc80-tail. Both the Ndc80- tail, which we reveal to be essential for microtubule end-tracking, and Ndc80-bound Ska stabilize microtubule ends in a stalled conformation. Modulation of force-coupling efficiency demonstrates *For correspondence: that the duration of stalled microtubule
    [Show full text]
  • Structure of Human Mad1 C-Terminal Domain Reveals Its Involvement in Kinetochore Targeting
    Structure of human Mad1 C-terminal domain reveals its involvement in kinetochore targeting Soonjoung Kima,b,1, Hongbin Suna,1,2, Diana R. Tomchickc, Hongtao Yua,b,3, and Xuelian Luoa,3 aDepartment of Pharmacology, bHoward Hughes Medical Institute, and cDepartment of Biochemistry, University of Texas Southwestern Medical Center, 6001 Forest Park Road, Dallas, TX 75390 Edited by Edward D. Salmon, University of North Carolina, Chapel Hill, NC, and accepted by the Editorial Board February 28, 2012 (received for review November 4, 2011) The spindle checkpoint prevents aneuploidy by delaying anaphase and sufficient for its kinetochore localization and checkpoint func- onset until all sister chromatids achieve proper microtubule attach- tion (18). By contrast, an N-terminal fragment of Xenopus Mad1 ment. The kinetochore-bound checkpoint protein complex Mad1- lacking the CTD has been shown to localize to kinetochores (19). Mad2 promotes the conformational activation of Mad2 and serves Finally, mutation of T680, a residue within the CTD and a poten- as a catalytic engine of checkpoint signaling. How Mad1 is targeted tial Plk1 phosphorylation site, in human Mad1 has been reported to kinetochores is not understood. Here, we report the crystal to diminish its kinetochore localization (20). It is thus unclear structure of the conserved C-terminal domain (CTD) of human whether Mad1 has conserved kinetochore-targeting domains. Mad1. Mad1 CTD forms a homodimer and, unexpectedly, has a fold The kinetochore receptor or receptors of Mad1 are also unknown. similar to those of the kinetochore-binding domains of Spc25 and In this study, we have determined the crystal structure of the Csm1.
    [Show full text]
  • Farewell Symposium Erich Nigg, Director Biozentrum
    Thursday, Farewell February 1, 2018 Lecture Hall 1, Pharmazentrum Klingelbergstrasse 50/70 Symposium Basel Erich Nigg, Director Biozentrum. Farewell Symposium Erich Nigg. 09.00 – 09.05 Welcome address 15.05 – 15.40 Time of change – change over time Erich Nigg, Director Biozentrum, University of Basel Katharina Sonnen, European Molecular Biology Laboratory, Heidelberg 09.05 – 09.40 Chromosomal dynamics during spermatogenesis in Drosophila melanogaster 15.40 – 16.15 Studies on NEK family kinases: From molecular Christian Lehner, Institute of Molecular Life Sciences, mechanisms to cancer therapies University of Zurich Andrew Fry, Department of Molecular and Cell Biology, University of Leicester 09.40 – 10.15 How do cells count centrosomes? Luca Fava, Centre for Integrative Biology, University of 16.15 – 16.45 Coffee Break Trento 16.45 – 17.20 Structure and function of the kinetochore 10.15 – 10.50 Checkpoint kinases: Beyond cell cycle control Andrea Musacchio, Max Planck Institute of Molecular Susan Gasser, Director of Friedrich Miescher Institute for Physiology, Dortmund Biomedical Research, Basel 17.20 – 17.55 Centrosome function and dynamics 10.50 – 11.15 Coffee Break Jordan Raff, Department of Biochemistry, University of Oxford 11.15 – 11.50 Regulation of cell growth and division Matthias Peter, Institute of Biochemistry, ETH Zurich 17.55 – 18.15 Short Break 11.50 – 12.25 The biology of hypoxia response pathways in cancer Wilhelm Krek, Molecular Health Sciences, ETH Zurich 18.15 – 18.25 Erich Nigg: Director of the Biozentrum Andrea Schenker-Wicki,
    [Show full text]
  • Growtharrestinyeastwithaberrant
    Growth arrest in yeast with aberrant [kinetochore] is rescued by the loss of [Gcn5] Biancamaria Ricci, Sara Monte, Stefano Vernarecci, Claudia Canzonetta, Paola Ballario, Patrizia Filetici Department of Orthopedics„ Washington University School of Medicine, St. Louis, MO, USA; Dept. Biology and Biotechnol- Correspondence ogy ”C.Darwin”, Institute of Molecular Biology and Pathology - CNR; Scientific Police Service, Forensic Genetics Laboratory, [email protected] Minister of Interior; Department of Immunology, IRCCS Bambino Gesù Children’s Hospital; Dept. Biology and Biotechnol- ogy ”C.Darwin”, Sapienza University of Rome; Sapienza University of Rome, Institute of Molecular Biology and Pathology - CNR Disciplines Genetics Keywords Abstract Ndc80 Complex The kinetochore provides the end-on attachment of central core complexes, suchas Kinetochore Ndc80, to the spindle microtubules (MTs) for a balanced chromosome segregation. The Saccharomyces Cerevisiae Gcn5 K-acetyltransferase Gcn5, involved in acetylation dependent processes, is also engaged Protein Subunits in the control of the cell cycle progression. Here we show that in budding yeast the deletion of the KAT GCN5 gene leads to a complete growth recovery of a strain missing Type of Observation the central kinetochore component Ndc80. Accordingly, we obtained full deletion of Standalone the essential, highly conserved, Ndc80 KT subunit in the gcn5Δ strain. We also demon- Type of Link strated that the deletion of Gim3, a subunit of the tubulin chaperone, abrogates the Standard Data recovery of cell growth in the ndc80-1-gcn5Δ strain suggesting an involvement of the kinetochore-MT attachment in this process. Our observations suggest the notion that Submitted Apr 12, 2017 ⴑ Published Jun 3, 2017 KAT Gcn5 exerts a regulatory role in the interaction of the central kinetochore Ndc80 complex to the spindle microtubules exhorting us to dig more into the mechanistic of this process.
    [Show full text]
  • A Molecular Basis for the Differential Roles of Bub1 and Bubr1 In
    RESEARCH ARTICLE elifesciences.org A molecular basis for the differential roles of Bub1 and BubR1 in the spindle assembly checkpoint Katharina Overlack1†, Ivana Primorac1†, Mathijs Vleugel2, Veronica Krenn1, Stefano Maffini1, Ingrid Hoffmann1, Geert J P L Kops3,4,6,7,8, Andrea Musacchio1,5* 1Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany; 2Molecular Cancer Research, University Medical Center Utrecht, Utrecht, Netherlands; 3Department of Molecular Cancer Research, University Medical Center Utrecht, Utrecht, Netherlands; 4Department of Medical Oncology, University Medical Center Utrecht, Utrecht, Netherlands; 5Centre for Medical Biotechnology, University Duisburg-Essen, Essen, Germany; 6Cancer Genomics Netherlands, University Medical Center, Utrecht, Netherlands; 7Department of Biology, Utrecht University, Utrecht, Netherlands; 8Netherlands Proteomics Center, Utrecht, Netherlands Abstract The spindle assembly checkpoint (SAC) monitors and promotes kinetochore–microtubule attachment during mitosis. Bub1 and BubR1, SAC components, originated from duplication of an ancestor gene. Subsequent sub-functionalization established subordination: Bub1, recruited first to kinetochores, promotes successive BubR1 recruitment. Because both Bub1 and BubR1 hetero-dimerize with Bub3, a targeting adaptor for phosphorylated kinetochores, the molecular basis for such sub- *For correspondence: andrea. functionalization is unclear. We demonstrate that Bub1, but not BubR1, enhances binding of Bub3 to [email protected].
    [Show full text]
  • Microtubules: 50 Years on from the Discovery of Tubulin
    PERSPECTIVES microtubule dynamics and organization VIEWPOINT emerge from a defined set of proteins Microtubules: 50 years on from through reconstitution experiments. Jonathon Howard. One of the big questions back when I got into the microtubule the discovery of tubulin business, around 1990, was how motor proteins such as kinesin and dynein use Gary Borisy, Rebecca Heald, Jonathon Howard, Carsten Janke, ATP hydrolysis to generate force for Andrea Musacchio and Eva Nogales transport along microtubules (such as axonal transport) or for cell motility (such as Abstract | Next year will be the 50th anniversary of the discovery of tubulin. ciliary or flagellar motion). The interaction To celebrate this discovery, six leaders in the field of microtubule research reflect of kinesin with microtubules was a model on key findings and technological breakthroughs over the past five decades, system, because it was clear that only a discuss implications for therapeutic applications and provide their thoughts on relatively small number of kinesins must what questions need to be addressed in the near future. be capable of moving small vesicles along microtubules. A related question was how microtubule growth and shrinkage could Identifying the main component of Rebecca Heald. In the mid-1990s, one generate force to move chromosomes microtubules was obviously the pressing question was why microtubules during mitosis. Polymerization and pressing task in the field around 50 years ago. in cells were so much more dynamic than depolymerization forces were very What key questions were being pursued microtubules assembled from purified mysterious: how could you hold on to the when you entered the arena of tubulin.
    [Show full text]
  • Research Interests – Prof. Dr. Andrea Musacchio
    Research Interests – Prof. Dr. Andrea Musacchio The main focus of Andrea Musacchio’s laboratory is the study of the molecular mechanisms supporting chromosome inheritance. As carriers of the genetic information stored in DNA (deoxyribonucleic acid), chromosomes play a crucial role in cellular and organismal heredity. Collectively, the 23 pairs of chromosomes present in each human cell carry almost exact copies of the three billion nucleotides of the human genome. In addition to be DNA carriers, chromosomes provide a protein-based scaffold that allows the genetic information contained in DNA to be decoded. Furthermore, and equally importantly, chromosomes act as units for the replication of the DNA in a mother cell and for its subsequent segregation into its two daughters. This foundational process in genetic heredity, which repeats itself in our bodies billions of times every day, is astonishingly accurate, with essentially negligible natural rates of chromosome gain or loss. However, this process goes often awry in tumours, generating imbalances in chromosome number that have dire consequences for cell physiology. Defects in this process are also observed in sexual reproduction, especially as a consequence of organismal aging, and represent prominent causes of infertility, miscarriage and birth de- fects. The series of events that allow a mother cell to replicate itself to generate two identical daughters is known as the cell cycle. This process is responsible for inter-generational prop- agation or organisms and for their development. In adult organisms, the cell cycle also pro- motes the continued, rapid renewal of many tissues, such as the intestine, the skin and the blood.
    [Show full text]
  • Spindly Attachments
    Downloaded from genesdev.cshlp.org on September 26, 2021 - Published by Cold Spring Harbor Laboratory Press PERSPECTIVE Spindly attachments Filiz Çivril1 and Andrea Musacchio1,2,3 1Department of Experimental Oncology, European Institute of Oncology, I-20139 Milan, Italy; 2Research Unit of the Italian Institute of Technology (IIT) Foundation at the IFOM-IEO Campus, I-20139 Milan, Italy The attachment of chromosomes to spindle microtu- and associated binding partners in the so-called consti- bules during mitosis is a delicate and intricate process on tutive centromere-associated network (CCAN; also which eukaryotic cells critically depend to maintain known as NAC/CAD) (Cheeseman and Desai 2008). The their ploidy. In this issue of Genes & Development, second module provides the core of the microtubule- Gassmann and colleagues (pp. 2385–2399) present an binding interface. Its most prominent component is the analysis of the recently discovered Spindly/SPDL-1 pro- KNL1–Mis12–Ndc80 complex (KMN) network, an array tein that casts new lights onto the attachment process of 10 proteins (Cheeseman and Desai 2008). Besides cre- and the way it relates to the control of cell cycle progres- ating a receptor for the microtubule, the KMN network sion. also serves as a recruitment pad for additional proteins, including molecular motors like dynein, which have been implicated in the early stages of attachment (see The basics below). Although the points of contact between the first Mitotic prometaphase is quite an eventful phase of the and second modules have not been elucidated, the two eukaryotic cell cycle. Its most characteristic trait is the modules contribute a structural core of the kinetochore mitotic spindle’s frantic engagement in the capture of that physically links chromosomes to spindle microtu- replicated chromosomes (the sister chromatids) that bules (Fig.
    [Show full text]
  • Edoardo (Born 03/02/2006) and Tommaso (Born 14/12/2008) Italian Citizenship
    Andrea Musacchio ORCID ID: 0000-0003-2362-8784 August 2019 Prof. Andrea Musacchio, PhD Director, Department of Mechanistic Cell Biology Max Planck Institute of Molecular Physiology, Dortmund, Germany Curriculum vitae Personal Born in Rome, 11 July 1964 Married to Roberta Palumbo Two kids: Edoardo (born 03/02/2006) and Tommaso (born 14/12/2008) Italian citizenship Education 1985-90 Degree in Biology, University of Rome-Tor Vergata (summa cum laude), Rome (Italy). Advisor: Prof Giovanni Cesareni 1991-95 PhD in Biochemistry at EMBL-University of Heidelberg (summa cum laude), Heidelberg (Germany). Advisor: Dr Matti Saraste Postdoctoral 1995-98 Postdoctoral Fellow at Harvard Medical School, Boston (USA). Advisor: Prof Stephen C. Harrison Appointments 1999-03 Assistant Professor, Department of Experimental Oncology, European Institute of Oncology, Milan (Italy) 2003-06 Associate Professor, Department of Experimental Oncology, European Institute of Oncology, Milan (Italy) 2006-2011 Full Professor, Department of Experimental Oncology, European Institute of Oncology, Milan (Italy) 2011- Director, Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund (Germany) Honors § Human Frontier Science Program postdoctoral fellow (1995-1997) § American Cancer Society Senior postdoctoral fellow (1997-1998) § Scholar of the Italian Foundation for Cancer Research (1999-2004) § EMBO Young Investigator (2000-2004) § Scientific Director of the Milan branch of SEMM (European School of Molecular Medicine) (2003-2006) § Chiara
    [Show full text]
  • Contents Will Come Baden-Württemberg Ministry of (OIPA) Several Times a Year
    1 EMBL July 1999 &cetera Newsletter of the European Molecular Biology Laboratory published by the Office of Information and Public Affairs News about services, staff, EMBL's PhD officially recognized science and society by Baden-Württemberg his is the first edition of a newsletter This will be a valuable resource if it The EMBL International PhD Pro- Tthat will be published by the EMBL receives interesting contributions. Ideally, gramme has received a letter from the Office of Information and Public Affairs a significant part of its contents will come Baden-Württemberg Ministry of (OIPA) several times a year. Its production from the staff. For the next issue, we are Science, Research, and the Arts is motivated by the need for an efficient soliciting the following types of contribu- announcing that the State is prepared to way to spread the word on issues relevant tions: treat a PhD degree granted by the to the entire Laboratory. Over the last Laboratory in the same way that other quarter of a century, EMBL has grown • news from each Outstation and from international PhDs are accepted. The from an easily-purveyable number of sci- Monterotondo; ministry has now recommended that entists busy at a single Laboratory to a • news from EMBO and the EMBC; the degree be recognized nation-wide, a large community spread over five sites in • announcements from services and the decision which must be made by a four countries, and at last count the num- computer group; national commission called the ber of our scientific Alumni has reached Kultusministerkonferenz. • announcements of upcoming talks or 1,500.
    [Show full text]
  • The Molecular Biology of Spindle Assembly Checkpoint Signaling Dynamics
    View metadata, citation and similar papers at core.ac.uk brought to you by CORE provided by Elsevier - Publisher Connector Current Biology Review The Molecular Biology of Spindle Assembly Checkpoint Signaling Dynamics Andrea Musacchio1,2 1Department of Mechanistic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany 2Centre for Medical Biotechnology, Faculty of Biology, University Duisburg-Essen, Essen, Germany Correspondence: [email protected] http://dx.doi.org/10.1016/j.cub.2015.08.051 The spindle assembly checkpoint is a safeguard mechanism that coordinates cell-cycle progression during mitosis with the state of chromosome attachment to the mitotic spindle. The checkpoint prevents mitotic cells from exiting mitosis in the presence of unattached or improperly attached chromosomes, thus avoiding whole-chromosome gains or losses and their detrimental effects on cell physiology. Here, I review a consid- erable body of recent progress in the elucidation of the molecular mechanisms underlying checkpoint signaling, and identify a number of unresolved questions. Introduction and Securin, in turn promoting their rapid destruction by the The spindle assembly checkpoint (SAC, also known as mitotic or proteasome [11,12]. By inhibiting the APC/C, the MCC stabilizes metaphase checkpoint) is a feedback-control system that oper- these substrates, effectively preventing mitotic exit. ates during cell division in eukaryotic cells [1–3]. The SAC mon- itors chromosome bi-orientation on the mitotic spindle, and as Kinetochores long as improperly attached chromosomes remain, it halts cells Kinetochores mediate chromosome attachment to microtu- in mitosis and precludes passage into the final phases of cell bules. They are complex multi-subunit structures with an ‘inner’ division (Figure 1).
    [Show full text]