MGC-Bulletin, Nr. 47, September 2012 In dit nummer:

MEDISCH-GENETISCH CENTRUM ZUID-WEST NEDERLAND - MGC

MGC-Bulletin, Nr. 47, September 2012 In dit nummer:

Coördinatie en redactie: M. Nivard/I. Braxhoven e-mail: [email protected]

: 071-5269605/9601

Onderwijs voor promovendi ........................... 2 PhD Teaching Programme Committee .......... 2 MGC Promovendi Workshop 2013 ................. 3 Promoties ......................................................... 3 Nieuwe medewerkers ...................................... 3 Lezingen/symposia ......................................... 4 Sectie 'DNA herstel-mechanismen'................ 5 Sectie ‘Lysosomal Storage Diseases’ ........... 5 Personalia ........................................................ 5 Prijzen ............................................................... 6 MGC-Bulletin no. 48 ........................................ 6 Program 22nd MGC Symposium ..................... 7 Abstracts 22nd MGC Symposium ................... 8 De MGC bestuurders en hun instituten ........ 18 Andere instituten/groepen binnen het MGC 18 Het MGC secretariaat ..................................... 18

De MGC AIO workshop 2012 in Düsseldorf was weer een groot succes!

Het Centrum is een initiatief van het Universitair Medisch Centrum Rotterdam en het Leids Universitair Medisch Centrum

From our sister school Molecular Medicine the following courses are available:  A "SNP Course" will be given 19-23 November 2012 in Rotterdam. The aim of this course is to give a broad introduction in SNP techniques and applications. The course is primarily organized for PhD students and postdocs. Other participants are also welcome on a “first- come-firstserved” basis. Max 60 participants. Topics: Study design, bio informatics for SNP's and hands-on-training, genotyping techniques and DNA management, data analysis, population identification and forensics; HapMap; Bio informatics for SNP's and GWA, hands-on training, applications in diseases, genetic risk factors and meta-analysis. For detailed information & registration info www.molmed.nl

Onderwijs voor promovendi Het aanbod van cursussen voor promovendi in het LUMC is tegenwoordig online beschikbaar. Deze informatie is te vinden op http://intranet.lumc.nl/kwo/scholing.htm. A course on "Next Generation Sequence data analysis” will be given 11 – 13 September 2012 in Rotterdam. It is open for MolMed and MGC members. This course aims at PhD students, postdocs and senior researchers who are interested in planning or already working with nextgeneration sequencing. We welcome researchers from both the genomics and bioinformatics fields. Currently available technologies as well as hardware solutions will be presented and discussed. The focus of the course will be on data and ways to analyse the data. There is a maximum of 60 places. For a complete programme, see the link at www.medgencentre.nl

Courses organized by Boerhaave CME:  Using R in Data Analysis: 28-30 November 2012. This 3-day course aims at helping researchers climb the steep learning curve, enabling them to perform basic data analysis and graphic displays at the end of the course, as well as giving a platform from which they can deepen their R knowledge later on if necessary.  Basic Methods and Reasoning in Biostatistics: 7 – 11 January 2013. In this course the basics of biostatistics will be covered and the participants will learn how to analyze problems in clinical research using SPSS. For detailed information & registration: www.boerhaavenet.nl

A workshop " ’Share your biotechnology research with a broad audience’" will be given on 27 September and 11 October in Leiden. Science journalists Marianne Heselmans and Astrid Smit have developed a workshop to learn to:  Get to know and understand your reader or listener.  Discover your own appealing and exciting story.  Write down this story in a clear and attractive way. More information and registration: www.medgencentre.nl A course on "Veilig werken in het laboratorium” will be given 13 December 2012 (Dutch version). The following points will be addressed: safe microbiological techniques; radionuclides; carcinogenic agents; blood, viruses; radiation. The course is also open for other new personal of the MGC. The course will be given twice a year depending on the interest in collaboration with the Department VSM of the LUMC. Apply through the MGC web site: www.medgencentre.nl or through the Boerhaave website: www.boerhaavenet.nl.

MGC-Bulletin no. 47; September 2012

PhD Teaching Programme Committee Since 2011 the MGC has a newly formed PhD Teaching Programme Committee. Members of the committee are: Raymond Poot and Kerstin Wendt of the Erasmus MC and Dorien Peters, Harry Vrieling and Madeleine Nivard of the LUMC. The committee will focus primarily on evaluation of the existing course program and will advise on new courses or teaching activities. (Contact email address: [email protected])

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strand break response". Promotor: Prof. L. Mullenders; co-promotoren: Dr. H. van Attikum en Dr. A. Pastink. Oluwatorotee Olusanya-Umuerri is op 12 september gepromoveerd in Rotterdam op het proefschrift "Caenorhabditis elegans response tos alt". Promotor: Prof. F. Grosveld; co-promotor: Dr. G. Jansen. Dwi Kemaladewi hoopt op 16 oktober te promoveren in Leiden op het proefschrift "From signal transduction to targeted therapy: interference with TGFbeta/myostatin signalling for Duchenne Muscular Dystrophy". Promotoren: Prof. G. van Ommen en Prof. P. ten Dijke; copromotoren: Dr. P. 't Hoen en Dr. W. Hoogaars. Jean-Charles Boisset hoopt op 25 oktober in Rotterdam te promoveren op het proefschrift "The origin of blood stem cells". Promotor: Prof. E. Dzierzak; co-promotor: Dr. C. Robin. Joost Melis hoopt op 6 november in Leiden te promoveren op het proefschrift "Nucleotide excision repair in aging and cancer". Promotoren: Prof. L. Mullenders en Prof. H. van Steeg; co-promotor: Dr. M. Luijten. Ali Aghajani hoopt op 14 november in Rotterdam te promoveren op het proefschrift "The role of ZBP-89 in globin regulation". Promotor: Prof. F. Grosveld. Polynikis Kaimakis hoopt op 15 november in Rotterdam te promoveren. Promotor: Prof. E. Dzierzak. Ook Ruben Musson hoopt op 15 november te promoveren, maar dan in Leiden, op het proefschrift "Calcineurin in skin: rising star or fallen angel". Promotor: Prof. L. Mullenders; co-promotor: Dr. N. Smit. Mischa Vrouwe hoopt op 20 november te promoveren in Leiden op het proefschrift "DNA damage response in mammalian cells. Focus on signaling and repair". Promotor: Prof. L. Mullenders.

MGC Promovendi Workshop 2013 Each year the MGC is organising a workshop for their PhD students and the last four years PhD students from the Institute of Genetic Medicine from the University of Newcastle are joining them. This meeting was originally conceived to give graduate students the opportunity to present their work to their peers in a relaxed and informal environment and to promote subsequent discussions and interactions. During this meeting graduate students have the opportunity to participate in discussions about each other's field of research, presented by either posters or presentations. This meeting is also a great opportunity to meet fellow graduate students, who could one day become your future colleagues or collaborators. This year's meeting from 29 May – 1 June in Düsseldorf was again a great success and we would like to invite all MGC graduate students to join the 2013 meeting. Pictures are posted on the website: www.mgcworkshop.nl/mgc2012 The MGC Ph.D.-student Workshop committee for the 20th edition is formed by Mattijs Heemskerk, José Maring, Irina Pulyakhina and Eleonora de Klerk. As usual Madeleine Nivard will assist them in making the plans, but we are still looking for some colleagues from Rotterdam! So please let us know if you are interested in joining the group!

Promoties Yahya Anvar is op 6 juni in Leiden gepromoveerd op het proefschrift "Converging models for transcriptome studies of human studies; the case of oculopharyngeal muscular dystrophy". Promotor: Prof. S. van der Maarel; copromotoren: Dr. P. 't Hoen, Dr. V. Raz en Dr. A. Tucker. Eddy van Roon is op 20 juni in Leiden gepromoveerd op het proefschrift "High throughput DNA methylation analysis in colorectal cancer and childhood leukemia". Promotoren: Prof. G van Ommen en Prof. H. Morreau; co-promotor: Dr. J. Boer. Godelieve Smeenk is op 11 september in Leiden gepromoveerd op het proefschrift "Chromatin remodelers in the DNA double


Nieuwe medewerkers Bij de afdeling Celbiologie (Rotterdam): Mike Dekker is begonnen als analist bij Raymond Poot en werkt aan factorenbetrokken bij de neurale differentiatie van embryonale stamcellen.

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Selmar Leeuwenburgh has been appointed on a NGI Zenith project as a research technician in the group of Thamar van Dijk and Sjaak Philipsen. He will perform an shRNA screen to identify and functionally characterize novel regulators of fetal to adult globin switching.

Bij de afdeling Moleculaire Epidemiologie (Leiden): René Luijk is sinds 16 augustus in dienst als OIO bij de afdeling Medische Statistiek & Bio-informatica. Zijn onderzoek richt zich op “Development and application of new statistical analysis tools for genomescale DNA methylation data”.

Bij de afdeling Genetica (Rotterdam): Imke Mandemaker is in dienst per 1 september als OIO. Ze komt op het project getiteld "Remodeling the UV response: Chromatin dynamics in Nucleotide Excision Repair". Supervisie: Dr. J.A.F. Marteijn. Franczka Wienholz is ook per 1 september in dienst als OIO. Ze komt het project getiteld "Deciphering the UV-induced DNA damage proteome". Supervisie: Dr. J.A.F. Marteijn. Serena Bruens zal per 1 oktober in dienst komen als OIO. Ze komt op het project getiteld: "The role of DNA damage and repair in treatment and prevention of prostate and bladder cancer". Supervisie: Dr. J. Pothof.

Lezingen/symposia Op 1 oktober om 16.00 uur spreekt in Collegezaal 1 (Erasmus MC, Rotterdam) Titia de Lange, Heinekenprijswinnares over "How shelterin solves the telomere endprotection problem". In het kader van het wetenschapscafé spreekt op 24 september om 19.30 uur: Prof.dr. Onno Steenbeek: "De toekomst van uw pensioen". Locatie: Dik T, Hoogstraat 10, Rotterdam (naast Centrale Bibliotheek) Op zondag 4 november 2013 organiseert het MGC, in samenwerking met het Centre for Medical Systems Biology (CMSB) en het Cancer Genomics Center (CGC) voor het zesde achtereenvolgende jaar een informatiemiddag in het Museum Boerhaave in Leiden onder de noemer "Wijzer over DNA". Prof. Joke Meijer en Prof. Bert van de Horst geven die middag een lezing. In totaal zullen er drie lezingen zijn die allen in het teken staan van de ‘Biologische klok’. Deze middag is gratis voor het publiek, maar i.v.m. de maximum capaciteit van 100 personen is inschrijving via de MGC website wel gewenst (www.medgencentre.nl). Op deze site is ook het programma te vinden.

Bij de afdeling Humane Genetica (Leiden): OIO's: Lusine Khachatryan werkt onder leiding van Jeroen Laros aan metagenomics in een forensische setting. Analisten: Lisanne Vijfhuizen is als analist werkzaam binnen de groep van Arn van den Maagdenberg. Zij doet bioinformatica studies bij het genetisch onderzoek naar migraine. Onderzoekers: Erno Vreugdenhil (associate professor) en Nicole Datson (assistant professor) zijn toegetreden tot de groep van Arn van den Maagdenberg om het stress-onderzoek in relatie tot het migraine mechanisme verder uit te bouwen. Julie Rutten is werkzaam als onderzoeker en bestudeert exon skipping bij Cadasil onder leiding van Dorien Peters en Annemieke Aartsma. Overig Majella Bak is sinds 16 maart werkzaam als secretaresse van Gert-Jan van Ommen. Leolien Bakker ondersteunt sinds 1 maart als secretaresse de BBMRI-NL.


Leidse Genetische Colloquia : LGC lezingen beginnen om 16.00 uur, tenzij anders aangegeven; minisymposia and Technology Platform Presentations beginnen om 13.30 uur. Locatie: één van de LUMC collegezalen. Voor meer informatie en het programma: [email protected] ESI Deze lezingen worden gehouden in het Erasmus MC, in zaal Ee-1024 van 12.3013.30 tenzij anders vermeld.

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(: 071-5269600) en Jan Hoeijmakers (: 010-7043199).

October 3: Marie Jose Goumans "TGFbsignalling povital in exogenous or endogenous cardiac cell based repair". November 21: Peter Zandstra "Synthetic stem cell niche engineering in vitro and in vivo". November 28: Cedric Blanpain; title not known yet, zaal Ae-406, 11:00 – 12:00 uur. Deze lezingenserie wordt georganiseerd door Elaine Dzierzak.

Sectie ‘Lysosomal Storage Diseases’ Eens per week overleggen betrokkenen van de afdelingen Kindergeneeskunde, Klinische Genetica, Neurologie, Interne Geneeskunde, Ziekenhuis Apotheek en andere afdelingen van het Erasmus MC over de lopende zaken wat betreft patiëntenzorg en onderzoek aangaande lysosomale stapelingsziekten. Hierbij staat de toepassing van enzymvervangingstherapie en daaraan gerelateerd onderzoek centraal (ziekte van Pompe, ziekte van Hurler, ziekte van Hunter en Maroteaux-Lamy). De bijeenkomsten worden gehouden in het Sophia kinderziekenhuis, Dr Molewaterplein 60, Rotterdam. Voor meer informatie kunt U terecht bij Arnold JJ Reuser: 010-7043153; [email protected].

NKI Seminars are given at the NKI, Plesmanlaan 121, Amsterdam: Location: Dc Auditorium, 11.00 hrs. Sept. 19: Jeroen van Heijst "Probing T cell immunity in clinical settings of immune deficiency and experimental tuberculosis infection" at room Z4. Sept. 28: Titia de Lange "How telomeres solve the chromosome end protection problem". Oct. 5: Edwin Cuppen: "Detection and decoding of structural variation in genomes". Oct. 12: Eric So: "Molecular dissection and targeting of epigenetic machinery in acute leukemia". Oct. 26: James Bradner: "Chemical inhibition of bromodomains". Nov. 2: Anton Wutz: "Derivation and characterization of haploid embryonic stem cells from mouse embryo" in the Piet Borst auditorium. Nov. 23: Niels Geijsen: "Dazl-in' Germ cells and pluripotent stem cells". Nov. 30: Joachim Lingner: "Telomerase structure and its regulation at chromosome ends". Dec. 7: Marileen Dogterom: "Positioning of microtubule organizing centers by pushing and pulling forces". Dec. 14: Charles Swanton: "Intratumour heterogeneity and personalised cancer medicine". Further info, also for the programme after December, at www.nki.nl

Personalia Berina Eppink (Genetica, EMC) heeft een Erasmus MC Grant gekregen, genaamd "Development of novel anti-cancer treatments based on localized induction of DNA repair deficiency by mild hyperthermia". Dit is een samenwerking met de Afdelingen Surgical Oncology en Radiation Oncology. Van de afdeling Genetica zijn de aanvragers: Jeroen Essers, Roland Kanaar en Berina Eppink. Sylvère van der Maarel (Humane Genetica, LUMC) is per 1 september benoemd tot afdelingshoofd Humane Genetica. Hij zal Gert-Jan van Ommen opvolgen, die op 28 september officieel afscheid neemt. Gert-Jan zal nog wel een aantal werkzaamheden, zoals CMSB en BBMRI-NL, blijven voortzetten. Barend Mons is op 15 maart 2012 benoemd tot bijzonder hoogleraar 'Biosemantiek'. Deze leerstoel is beschikbaar gesteld door Stichting NBIC en is voor de duur van 5 jaar.

Sectie 'DNA herstel-mechanismen' De volgende bijeenkomst zal plaatsvinden op vrijdag 26 oktober in Rotterdam, Erasmus MC, aanvang 9.30 uur. Deze sectie komt ca. 1 x per 2 maanden bijeen op een vrijdagochtend, alternerend in Leiden en Rotterdam. Coördinatoren: Leon Mullenders


De onderzoeksgroep Functional Cell Anatomy onder leiding van Prof. dr Adriaan B. Houtsmuller van het Erasmus Optical Imaging Centre (OIC), Erasmus MC, is per 1 september opgenomen in het MGC. Houtsmuller werkt sinds 1995 aan het Erasmus MC, waar hij destijds in het kader 5

Hierdoor zijn ze herkenbaar en ontstaan er aangrijpingspunten om ze te vernietigen. Prof. Hoeijmakers, bij een breed publiek bekend als ‘ouderdomsprofessor’, is een groot expert op het gebied van DNA-herstel. Het DNA in lichaamscellen wordt voortdurend beschadigd door factoren zoals UV-straling en gifstoffen. Die beschadigingen kunnen leiden tot fouten in het DNA (mutaties). Gelukkig kunnen mutaties in het DNA gerepareerd worden. Bij kankercellen zijn sommige reparatiesystemen echter beschadigd, waardoor kankercellen niet goed kunnen reageren op schade aan het DNA. Prof. Hoeijmakers doet onderzoek naar het verschil tussen normale en kankercellen, zodat het mogelijk wordt de kankercellen te herkennen en selectief te treffen en het gezonde weefsel intact te laten. Het onderzoek omvat:  een analyse van een groot aantal tumorsamples om beter te begrijpen hoe DNA-schaderespons bij prostaaten blaaskanker werkt en welke defecten daarin optreden;  het ontwikkelen van nieuwe methoden om met behulp van nog levend tumorweefsel vast te stellen of er een defect in de DNAschaderespons optreedt en zo ja welk;  nieuwe behandelingen ontwikkelen die selectief de tumor doden en het gezonde weefsel (nagenoeg) ongemoeid laten. Dit biedt mogelijk ook nieuwe aanknopingspunten voor preventie bij personen met een erfelijke gevoeligheid voor prostaaten blaaskanker.

van een gezamenlijke NWO-subsidie van Erasmus MC (Bosman) en LUMC (Tanke) de eerste confocale microscoop voor het onderzoek aan die instituten implementeerde. Momenteel is het daaruit voortgekomen Erasmus OIC een veelzijdig, intensief bezocht expertisecentrum voor microscopie. De onderzoeksgroep Functional Cell Anatomy werkt aan het ontrafelen van moleculaire regulatiemechanismen van gentranscriptie, DNA reparatie en celmigratie en aan de vraagstellingsgerichte ontwikkeling van kwantitatieve microscopische technologie. Catherine Robin heeft een ERC starting grant verworven (€ 1.5 million for 5 years): "From mesoderm to hematopoietic stem cell commitment: cellular and molecular events occurring during mouse embryonic development".

Prijzen Jan Hoeijmakers (Genetica, EMC) heeft op 6 december 2011 de KWO prijs (KWF Kankerbestrijding) in ontvangst mogen nemen. In verband hiermee is een aantal bijzondere evenementen georganiseerd: www.ridefortheroses.nl Opbrengst Ride for the Roses Westland 2012 voor nieuwe aanpak prostaaten blaaskanker Het doel van de Ride for the Roses is het geld inzamelen voor KWF Kankerbestrijding. Elk jaar wordt er samen met KWF Kankerbestrijding een nieuw projectdoel gekozen, deze is gekoppeld aan de KWOprijs. De opbrengst van de Ride for the Roses 2012 zal ten goede komen aan onderzoek voor nieuwe aanpak prostaaten blaaskanker onder leiding van prof.dr. Jan Hoeijmakers, hoogleraar Moleculaire Genetica aan het Erasmus Medisch Centrum Rotterdam. Prof. Hoeijmakers hoopt met zijn baanbrekend onderzoek over vijf tot tien jaar met nieuwe behandelmethoden te komen voor prostaaten blaaskanker, waardoor de ziekte teruggedrongen en in sommige gevallen geheel genezen kan worden. Zijn onderzoek berust op het feit dat elke cel continu fouten in het DNA herstelt. Vaak maken kankercellen gebruik van andere reparatiemechanismen dan normale cellen.


MGC-Bulletin no. 48 Het achtenveertigste MGC Bulletin is gepland voor maart 2013. De sluitingsdatum voor kopij is gesteld op 15 januari 2013. Mededelingen, nieuws, agendapunten en andere wetenswaardigheden gaarne per e-mail inleveren bij Madeleine Nivard of Ingrid Braxhoven, afdeling Toxicogenetica,  071-5269605/ 5269601;e-mail: [email protected]/ [email protected]

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22nd MGC-SYMPOSIUM Thursday, September 13, 2012 Building 3, LUMC Program 22nd MGC Symposium 8.45 coffee and registration 9.30 9.35 9.55 10.15 10.35

10.55 11.15 11.35 11.55 12.15

opening: F.G. Grosveld Chairman: F.G. Grosveld Anastasia Egorova: “Ciliary regulation of endothelial response to shear stress. Consequences for TGFbeta signaling and endothelial-to-mesenchymal transition” (Anatomy and Embryology, LUMC) Linde Kegel: “The functional relationship between Lgi proteins and PNS myelin formation” (Genetics, Erasmus MC) Eleonora de Klerk: " Poly(A) binding protein nuclear 1 (PABPN1) levels affect alternative polyadenylation " (Human Genetics, LUMC) Marialuisa Quadri: " Mutations in SLC30A10 Cause Parkinsonism and Dystonia with Hypermanganesemia, Polycythemia, and Chronic Liver Disease " (Clinical Genetics, Erasmus MC) coffee/tea Chairman: G.J.B. van Ommen Joris Deelen: “Genome-wide association study to identify new loci contributing to survival into old age” (Molecular Epidemiology, LUMC) Thomas Clapes: “Role of CLASP2 during mouse embryonic and adult haematopoiesis” (Cell Biology, Erasmus MC) Bram Herpers: “Live cell imaging multiparametric RNAi screen of the NFkB nuclear oscillatory response identifies novel regulators of the ubiquitinase A20” (LACDR-Toxicology, UL) Julie Rutten: “Cysteine Quantity Correction in CADASIL; modification of the NOTCH3 protein using antisense oligonucleotides” (Human and Clinical Genetics, LUMC)

12.35 -14.00 lunch 14.00 14.20 14.40

15.00 15.20 15.40 16.00 16.30

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Chairman: B. v.d. Water Jessica Zuin: “Cohesin’s role for the higher order chromatin structure at the chromosome 11 p15.5 region” (Cell Biology, Erasmus MC) Thomas Costelloe: “The yeast Fun30 and human SMARCAD1 chromatin remodelers are novel factors involved in the repair of chromosomal DNA breaks” (Toxicogenetics, LUMC) Khek-Chian Tham: “Anti-recombination mediated by DNA mismatch repair proteins” (Genetics, Erasmus MC) Chairman: R.M.W. Hofstra Ashok Reddy: “Metabolic enzyme GMP synthetase relays control of p53” (Biochemistry, Erasmus MC) Laurens van Meeteren: “Neuropilin-1 signaling in trans regulates VEGF signaling and angiogenesis” (Molecular Cell Biology, LUMC) Marten van der Zee: “Aldehyde dehydrogenase activity earmarks cancer stem cells in endometrial cancer” (Josephine Nefkens Institute, Erasmus MC) coffee/tea Chairman: L.H.F. Mullenders MGC Symposium Lecture: Prof. dr. Karen Adelman: Potentiating Signal-responsive Transcription: A Dynamic Dance Between Paused Polymerase and Chromatin (Laboratory of Molecular Carcinogenesis, Research Triangle Park, USA ) drinks


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Abstracts 22nd MGC Symposium Ciliary regulation of endothelial response to shear stress. Consequences for TGFbeta signaling and endothelial-to-mesenchymal transition Anastasia Egorova Anatomy and Embryology/Molecular Cell Biology, LUMC Primary cilia are cellular protrusions which serve as mechanosensors for fluid flow. In endothelial cells (ECs) they function in transducing local blood flow information into functional responses, like nitric oxide production and modulation of gene expression. Cilia are present on ECs in areas of low or disturbed flow and absent in areas of high flow. In the embryonic heart high flow regime applies to the endocardial cushion area, and the absence of cilia here coincides with the process of endothelial-to-mesenchymal transition (EndoMT). EndoMT is responsible for populating the cushions with cells. In this process ECs lose their endothelial characteristics, acquire a mesenchymal phenotype and delaminate from the luminal surface into the cushion matrix. We investigated the role of the primary cilium and the associated signalling pathways in defining the responses of ECs to fluid shear stress and in EndoMT and elucidate the underlying mechanisms. Non-ciliated mouse embryonic ECs with a mutation in Tg737/Ift88 were used to compare the response to fluid shear stress to that of ciliated wild-type (WT) ECs. In vitro, non-ciliated ECs undergo shear-induced EndoMT which is accompanied by downregulation of Klf4. This Tgfβ/Alk5 dependent transformation is prevented by blocking Tgfβ signaling, overexpression of Klf4, or rescue of the primary cilium. We also show that specifically Tgfβ2 signaling through TgfβR3 is required for flow-induced EndoMT. In the hearts of Tg737orpk/orpk embryos Tgfβ/Alk5 signaling was activated in areas in which ECs would normally be ciliated, but now lack cilia due to the mutation. In these areas ECs show increased Smad2 phosphorylation and expression of αSMA. In addition, ligand (in-)dependent Hedgehog (Hh) signaling in nonciliated ECs was compared to ciliated WT ECs. ECs lacking primary cilia have high levels of Gli1 and are non-responsive to (canonical) ligand stimulation. This study demonstrates the central role of primary cilia in rendering ECs prone to shearinduced activation of Tgfβ2/Alk5 signaling and EndoMT and provides a functional link between primary cilia and flow-related endothelial performance. In addition, primary cilia serve as a switch between ligand dependent and independent Hh signaling in ECs.

The functional relationship between Lgi proteins and PNS myelin formation Linde Kegel Genetics, Erasmus MC Defects in myelination cause diverse forms of neurological disease, underscoring the importance of myelin for the normal structure and function of the nervous system. Interactions between Schwann cells and neurons shape the development and function of nerve tissue and regulate myelin formation. However, so far only few molecules involved in this communication process have been described. Recently we identified the Lgi4 gene as a major regulator of nerve development and function [1]. The Lgi4 gene was found mutated in the natural mouse mutant claw paw, which is characterized by limb posture abnormalities, delayed axonal sorting and hypomyelination in the PNS [2-3]. Lgi4 is a member of a gene family that encodes secreted proteins containing a Leucine-rich repeat


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domain and an epitempin or epilepsy associated domain [4]. The latter domain most likely folds into a seven-bladed propeller structure, a structural motif found in a wide variety of proteins. Both protein domains are generally involved in protein-protein interactions. It is suggested that members of the Adams family function as receptors for Lgi4 and other Lgi family members [5]. In particular, Lgi4 binds Adam22 and Adam22 null mice exhibit a peripheral nerve phenotype similar to that of claw paw mice. Genetic evidence has shown that Adam22 is required in neurons of the PNS [6]. Thus, Lgi4-Adam22 interactions play a crucial role in the development and functional maturation of the nervous system. However, as other members of the Lgi family also bind to Adam22 and are widely expressed in the nervous system we asked whether these proteins are functionally equivalent to Lgi4 in the PNS and, additionally, what protein domains within the Lgi proteins are relevant for stimulating myelin formation. Using a Schwann cell-neuron co-culture system derived from claw paw embryos we demonstrate that Lgi4 function is specifically required in Schwann cells to stimulate myelination as its function cannot be replaced by any of the other Lgi proteins. Furthermore, we show that this specificity critically depends on protein sequence within the carboxy-terminal half of the epitempin domain of Lgi4. Interestingly, a mutation in this domain that compromises Lgi1 function and causes epilepsy in humans does not compromise Lgi4 function in the PNS. To further identify functionally relevant sequences within the Lgi4 protein we took advantage of the more than 900 million years of independent evolutionary history between modern day fishes and mammals. Curiously, comparative genomics had failed to identify an Lgi4 homologue among the five Lgi genes in the genomes of fish. However, we found that zebrafish Lgi1A and to a lesser degree Lgi1B, can functionally replace Lgi4 and stimulate myelin formation in our co-culture system. Careful sequence alignment between fish Lgi1A and mammalian Lgi4 proteins identifies two short peptide sequences that are conserved and that map next to each other on the outer surface of the epitempin domain, suggesting that this patch represents an interaction domain that uniquely distinguishes Lgi4 function from that of Lgi1. Thus, despite the fact that both Lgi1 and Lgi4 biological functions are mediated through Adam22, the functional outcome of these interactions is distinct.

Poly(A) binding protein nuclear 1 (PABPN1) levels affect alternative polyadenylation Eleonora de Klerk Human Genetics, LUMC The choice for a polyadenylation site (PAS) determines the length of the 3'-untranslated region (3’-UTRs) of an mRNA. Inclusion or exclusion of regulatory sequences in the 3’-UTR may ultimately affect gene expression levels. Poly(A) binding protein nuclear 1 (PABPN1) is involved in polyadenylation of pre-mRNAs. A repeat expansion in PABPN1 causes oculopharyngeal muscular dystrophy (OPMD), a late onset and progressive muscle disorder. Microarray expression profiling of mice overexpressing expandedPABPN1 showed alternative PAS usage in 8% of the interrogated genes. We hypothesized that previously observed disturbed gene expression patterns in OPMD muscles may have been the result of an effect of PABPN1 on alternative PAS usage. To explore PAS usage on a genome-wide level, we developed a single molecule PAS sequencing method. We identified 2,012 transcripts with altered PAS usage. In the far majority, alternative more proximal PAS were used. This resulted in overall shortening of 3’UTRs and increased expression for most of the transcripts. We recapitulated these changes in PAS usage in myogenic cells by low overexpression of expanded but not wild-type PABPN1. Since expanded-PABPN1 is known to be trapped in intranuclear inclusions, we investigated the effect of sh-RNA mediated downregulation of PABPN1. We found that reduced Pabpn1 levels also resulted in shortening of 3’-UTRs. Our data suggest that PABPN1 is involved in PAS selection. We propose therefore that reduced


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availability of functional PABPN1 in OPMD muscles results in use of alternative, proximal PAS, leading to large-scale deregulation of gene expression.

Mutations in SLC30A10 Cause Parkinsonism and Dystonia with Hypermanganesemia, Polycythemia, and Chronic Liver Disease Marialuisa Quadri Clinical Genetics, Erasmus MC Manganese is essential for several metabolic pathways but becomes toxic in excessive amounts. Manganese levels in the body are therefore tightly regulated, but the responsible protein(s) remain incompletely known. We studied two consanguineous families with neurologic disorders including juvenile-onset dystonia, adult-onset parkinsonism, severe hypermanganesemia, polycythemia, and chronic hepatic disease, including steatosis and cirrhosis.We localized the genetic defect by homozygosity mapping and then identified two different homozygous frameshift SLC30A10 mutations, segregating with disease. SLC30A10 is highly expressed in the liver and brain, including in the basal ganglia. Its encoded protein belongs to a large family of membrane transporters, mediating the efflux of divalent cations from the cytosol.We show the localization of SLC30A10 in normal human liver and nervous system, and its depletion in liver from one affected individual. Our in silico analyses suggest that SLC30A10 possesses substrate specificity different from its closest (zinc-transporting) homologs. We also show that the expression of SLC30A10 and the levels of the encoded protein are markedly induced by manganese in vitro. The phenotype associated with SLC30A10 mutations is broad, including neurologic, hepatic, and hematologic disturbances. Intrafamilial phenotypic variability is also present. Chelation therapy can normalize the manganesemia, leading to marked clinical improvements. In conclusion, we show that SLC30A10 mutations cause a treatable recessive disease with pleomorphic phenotype, and provide compelling evidence that SLC30A10 plays a pivotal role in manganese transport. This work has broad implications for understanding of the manganese biology and pathophysiology in multiple human organs.

Genome-wide association study to identify new loci contributing to survival into old age Joris Deelen Molecular Epidemiology, LUMC Human longevity is a complex trait which is mainly influenced by environmental factors, like nutrition, hygiene and health care. From twin studies it was estimated that the genetic contribution to human lifespan variation is about 25 – 30%. However, up till now, very few genes influencing longevity have been identified and genome-wide association studies (GWAS) revealed only one common locus influencing survival into old age; apolipoprotein E (APOE). In order to identify additional common longevity loci, we conducted a metaanalysis with (imputed) GWAS data of 7,729 long-lived cases aged over 85 years and 16,121 younger controls (< 65 years of age) of European descent. In addition, we analyzed a more stringent selection of cases older than 90 years of age (n = 5,406). In the discovery phase indeed the APOE locus, for which the ApoE ε4 allele contributes to increased mortality and the ApoE ε2 allele to longevity, reached genome-wide significance (rs4420638; P = 6.14 x 10-19 (cases ≥ 85 years) and P = 4.09 x 10-21 (cases ≥ 90 years)) and


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14 loci showed p-values between 1 x 10-5 and 5 x 10-8 in one of the two meta-analyses. These 14 potential longevity loci are currently being tested for association in at least 3,500 additional cases (≥ 85 years of age) and 5,000 younger controls (< 65 years of age). We will test which of the 14 loci will reach a p-value < 0.003 (significance after adjustment for multiple testing) within the replication phase.

Role of CLASP2 during mouse embryonic and adult haematopoiesis Thomas Clapes Cell Biology, Erasmus MC Hematopoietic Stem Cells (HSCs) are generated during embryonic development. They are first detected in the Aorta-Gonad-Mesonephros (AGM) region at mid-gestation. HSCs remain attached to the aortic endothelium until they migrate to the fetal liver, where they expand, before colonizing the bone marrow prior to birth. Cell attachment, migration, and division are very important for HSCs. It is known that the microtubule (MT) cytoskeleton plays an important role in these processes, however, little is known about the organization and function of this network in HSCs. Mammalian CLASPs are MT plus-end tracking proteins that play essential roles in the local regulation of MT dynamics. To determine the function of CLASPs in vivo, we have generated Clasp2 knockout mice. Although viable, the mice have thrombocytopenia, progressive anemia, and pancytopenia. Importantly, the Clasp2 knockout mice have a strong HSC defect, as these cells do not home efficiently towards their niche and are not properly maintained in the bone marrow. Furthermore, MT stability and organization are affected in HSCs upon attachment. Interestingly, HSC-enriched populations sorted from the bone marrow of Clasp2 knockout mice contain reduced mRNA levels of two essential factors for HSC maintenance: c-Mpl (thrombopoietin receptor) and Meis1, a transcription factor regulated by c-Mpl. To determine whether CLASP2 also plays a role in HSC activity during development, we performed in vivo transplantations with cells isolated from the AGM and fetal liver of Clasp2 knockout embryos. We observed a dramatic HSC defect indicating that normal expression of CLASP2 in HSCs is crucial for their generation and/or maintenance in the AGM and for a proper expansion in the fetal liver. We propose that CLASP2-mediated stabilization of MTs is required for HSC homing, attachment, and signalling, and is necessary to activate specific transcription programs involved in HSC maintenance in the adult bone marrow and possibly also during embryonic development. This is the first time that a deficiency in a MT-tethering protein has been linked to defects in the transcription of essential HSC genes.


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Live cell imaging multiparametric RNAi screen of the NFkB nuclear oscillatory response identifies novel regulators of the ubiquitinase A20 Bram Herpers LACDR-Toxicology, UL Stimulation of cells with the cytokine TNF-alpha (TNFα) triggers cytoplasmic-to-nuclear oscillation of the dimeric transcription factor NF-kappaB (NF-κB). In the nucleus, NF-κB stimulates transcription of its own response inhibitors, IkappaBalpha (IκBα) and the deubiquitinase A20. The concerted induction of IκBα and A20 functions to prevent over-activation of the response and timedependent inactivation is observed as a dampened NF-κB nuclear oscillation pattern. The number of nuclear oscillations dictates the transcription of downstream pro-inflammatory, anti-oxidant and antiapoptotic genes. The number of nuclear translocation events is markedly reduced under hepatotoxic drug (diclofenac) exposure conditions in association with enhanced apoptosis. To understand the mechanism of the perturbed oscillatory response, we used a live-cell imaging-based siRNA screen to identify individual kinases and ubiquitinases that control the NF-κB oscillatory response. We applied high content confocal laser scanning microscopy in combination with multiparametric image analysis to follow the NF-κB oscillation in ~300 individual cells per condition simultaneously. Out of the ~1500 kinases and (de)ubiquitinases we identified 115 that significantly affected the NF-κB oscillatory response. Using 4 individual siRNAs we confirmed the action for 49 genes. These 49 either altered the amplitude or duration of nuclear oscillations, or the time between oscillations, leading to an increase of the number of nuclear translocations, or an inhibition of the response altogether. In this last category we identified six genes, four novel, whose reduced expression protects against the diclofenac/TNFα-induced apoptosis. Interestingly, the knockdown of these six genes led to a basic upregulation of A20 expression. In contrast, A20 knockdown promoted the NF-κB oscillation and enhanced apoptosis. Moreover, double knockdown experiments indicated a direct relationship between these six genes and A20 in the control of the NF-κB activation and apoptosis. These findings indicate that the deubiquitinase A20 is a master regulator in the life-death decision upon TNFα stimulation in drug-induced hepatotoxic responses, which, in turn, is kept under control by a network of genes that control its expression levels.

Cysteine Quantity Correction in CADASIL; modification of the NOTCH3 protein using antisense oligonucleotides Julie Rutten Human and Clinical Genetics, LUMC CADASIL (Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy) is the most common monogenetic cause of ischemic stroke and vascular dementia, caused by highly stereotyped missense mutations in the NOTCH3 gene. Mutations in CADASIL invariably lead to the gain or loss of a cysteine residue in one of the epidermal growth factor repeats (EGFR) of the NOTCH3 protein. This causes disrupted disulphide bridge formation and NOTCH3 aggregation, leading to vascular smooth muscle cell (VSMC) degeneration and disturbed cerebral blood flow. We have developed a potential therapeutic strategy for CADASIL aimed at preventing NOTCH3 aggregate formation (Cysteine Quantity Correction, CQC). In CQC, antisense oligonucleotides (AON) are used to skip targeted exons from the NOTCH3 premRNA in order to restore the number of cysteines in the mutated EGFR. Skipping of


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NOTCH3 exons 4 and 5 targets up to 70% of CADASIL mutations, and is predicted to result in an internally deleted protein with an EGFR fusion domain with normal disulphide bridge formation (NOTCH3CQC). Using a cocktail of 3 AON, CQC exon skipping has been proven efficient and robust in multiple cell models. Currently, we are optimizing experimental conditions to determine the processing and function of the NOTCH3CQC protein. Human NOTCH3 transgenic mice with an archetypal CADASIL mutation have been generated and will be used to study CQC exon skipping in vivo, starting with the optimization of AON administration. Taken together, these studies will form the basis for future studies aimed at determining the therapeutic effect of CQC exon skipping on the CADASIL phenotype.

Cohesin’s role for the higher order chromatin structure at the chromosome 11 p15.5 region Jessica Zuin Cell Biology, Erasmus MC Cohesin is a chromosome associated protein with several functions such as sister chromatids cohesion, DNA double strand break repair and insulation function. Cohesin co-localizes genome-wide with CCCTCbinding factor (CTCF) and it is essential for CTCF-insulation activity (2,3). Since the insulation function has been related with long range chromosomal interactions (1), our hypothesis is that cohesin might mediate chromatin insulation by promoting the formation of this higher order chromatin structures. In particular, we are interested in understanding whether cohesin/CTCF-binding sites are in general involved in the formation of long range chromosomal interactions, how cohesin/CTCF organize the chromatin and the relevance of the chromatin loops for gene activity. To analyze cohesin-dependent chromatin loops, I improved the 3C-sequencing (Chromosome Conformation Capture) technique in a way that allows us to study multiple regions at the same time. We started to analyze the organization of the human imprinted IGF2-H19 locus, with already know cohesin/CTCF-dependent chromosomal interactions (1). To study the structure of the IGF2-H19 locus by 3C-sequencing, we have chosen three different regions (or viewpoints) corresponding to different cohesin/CTCF binding sites within the locus: CTCF AD (cohesin/CTCF-binding site upstream the IGF2 gene), Centrally Conserved Domain (CCD) and CTCF DS (cohesin/CTCF-binding site downstream the H19 gene). The results of the sequencing show a structure of almost 1Mb, spanning on the chr11p15.5 region and forming three distinct domains: the major domain is represented by the IGF2-H19 locus, the second domain is located upstream the locus and the third one is downstream the locus. At the IGF2-H19 locus we found that the three cohesin/CTCF binding sites, used as viewpoints, strongly interact forming in this way the structure of the locus, as already demonstrated by 3C-qPCR (1). In the upstream region we found novel intra-chromosomal contacts between the three cohesin/CTCF binding sites and the TNNT3, LSP1 and KRTAP5 genes while in the downstream region the main interactions were with the KCNQ1 locus. Interestingly, all these interactions involve only inactive genes, suggesting that the domains might form active and inactive chromatin hubs. To further investigate the structure of the chr11p15.5 region, we planned to perform the 3C-sequencing using new viewpoints localized at the border of the domains detected. The interactions found will be tested to understand their dependency from cohesin and the influence of the activity of the genes involved by both 3C-seq and 3C-qPCR methods and RT-qPCR in cohesin depleted cells.


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The yeast Fun30 and human SMARCAD1 chromatin remodelers are novel factors involved in the repair of chromosomal DNA breaks Thomas Costelloe Toxicogenetics, LUMC Several homology dependent pathwayscan repair potentially lethal DNA double strand breaks (DSBs). The first step common to all homologous recombination reactions is the 5'-3' degradation of DSB ends that yields 3' single-stranded DNA (ssDNA) required for loading of checkpoint and recombination proteins. The Mre11-Rad50Xrs2/NBS1 complex and Sae2/CtIPinitiate end resection while longrange resection depends on the exonuclease Exo1 or the helicasetopoisomerase complex Sgs1-Top3-Rmi1 with the endonuclease Dna2. DSBs occur in the context of chromatin, but how the resection machinery navigates through nucleosomal DNA is a process that is not well understood. Here, we show that the S. cerevisiae yeast Fun30 protein and its human counterpart SMARCAD1, two poorly characterized ATP-dependent chromatin remodelers of the Snf2 ATPase family, are novel factors that are directly involved in the DSB response in yeast and human cells, respectively. Fun30 physically associates with DSB ends and directly promotes both Exo1- and Sgs1-dependent end resection through a mechanism involving its ATPase activity. The function of Fun30 in resection facilitates repair of camptothecin-induced DNA lesions, and it becomes dispensable when Exo1 is ectopically overexpressed. Interestingly, SMARCAD1 is also recruited to DSBs and the kinetics of recruitment is similar to that of Exo1. Loss of SMARCAD1 impairs end resection, recombinational DNA repair and renders cells hypersensitive to DNA damage induced by camptothecin or PARP inhibitor. These findings unveil an evolutionarily conserved role for the Fun30 and SMARCAD1 chromatin remodelers in controlling end resection, homologous recombination and genome stability in the context of chromatin. Anti-recombination mediated by DNA mismatch repair proteins Khek-Chian Tham Genetics, Erasmus MC Homologous recombination, a process of DNA strand exchange between two homologous DNA molecules, is important for DNA repair, including that of double-strand breaks, and for efficient DNA replication. DNA strand exchange in Escherichia coli is mediated by the recombinase RecA. DNA mismatch repair (MMR) corrects replication errors and prevents accumulation of mutations in the genome. When the sequences of two recombining duplexes diverge, DNA MMR proteins prevent this heterologous recombination event. In vivo, interspecies conjugational crosses between E. coli and Salmonella typhimurium are orders of magnitude more efficient in MutS-, MutL-, MutH- or UvrD-mutant recipients compared to wild-type recipients [1]. In vitro, the formation of heteroduplex product from recombination between M13 and fd bacteriophage DNA is inhibited by E. coli MutS and MutL [2]. We probed the mechanism of this reaction using purified proteins and DNA substrates. We uncovered how the mismatch recognizing proteins MutS and MutL trap intermediates generated by recombination proteins and how a DNA helicase, UvrD, is recruited to directionally resolve these intermediates back into DNA substrates. Our model explains how the interplay between two DNA repair systems allows cells maintain genome stability.


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Metabolic enzyme GMP synthetase relays control of p53 Ashok Reddy Biochemistry, Erasmus MC Integrity of the eukaryotic genome is constantly challenged by the genotoxic stress factors. Cells have evolved counteractive mechanisms to overcome the stress. Among these, stabilization of p53 is found to be the major mechanism to carry out cellular adaptation to stress. p53 is a transcription factor that mediates the stress response through the transcriptional activation or repression of genes involved in cell cycle regulation, apoptosis and metabolism. p53 stability is regulated by ubiquitin dependent mechanisms mainly catalyzed by E3-ubiquitin ligase MDM2 that induces p53 degradation. However, stabilization of p53 by deubiquitilation upon stress is poorly understood. Here, we report that biosynthetic enzyme GMP synthetase stabilizes p53 by forming a complex with the deubiquitilase USP7 upon stress. GMPS predominantly resides in the cytoplasm in unstressed cells but translocate into the nucleus upon induction of stress and stabilizes p53 through the USP7-mediated deubiquitilation. Thus, GMPS acts as a metabolic sensor and activates the p53-mediated replicative stress response to the nucleotides depletion. We have obtained evidence suggesting that the GMPS subcellular localization is controlled in an ubiquitilation-dependent manner. We will present results of experiments aimed at identifying the relevant E3 ubiquitin ligase that determines GMPS localization, and consequently p53 levels. We conclude that the nucleotide biosynthetic enzyme GMPS acts as a switch that relays p53 induction. These findings uncovered a novel pathway to regulate the tumor-suppressor p53.


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Neuropilin-1 signaling in trans regulates VEGF signaling and angiogenesis Laurens van Meeteren Molecular Cell Biology, LUMC The tumor-stroma microenvironment plays a key role in cancer progression and metastasis, particularly through the neovascular supply of growth factors, nutrients and oxygen. Increased tumor vascularization and expression of angiogenic factors has been associated with poor clinical prognosis. Angiogenesis, formation of new blood vessels, is regulated by growth factors such as vascular endothelial growth factor (VEGF) which stimulates endothelial cells to secrete proteases, and to migrate, proliferate and differentiate. VEGF signals via different tyrosine kinase VEGF receptors such as the VEGF receptor 2 (VEGFR2). In addition, there are the neuropilin co-receptors that form a complex with the signalling receptors and determine the biological outcome of VEGFsignalling. We show that blocking neuropilin-1 (NRP1), by the use of blocking antibodies, inhibits vascular sprouting in a 3D model for angiogenesis. In addition we have studied the role of NRP1-VEGFR2 complex formation in trans (i.e. complex formation between cells individually expressing either VEGFR2 or NRP1). Proximity ligation assays showed that complex formation in trans occurred at the interface between VEGFR2- and NRP1-expressing cells. The complexes in trans established slower and remained for a prolonged time at the cell-cell interface whereas complexes in cis (i.e. between VEGFR2 and NRP1 co-expressed in the same cell) rapidly became internalized and degraded. Since internalization of VEGFR2 is needed for its efficient signaling, we hypothesized that VEGFR2-mediated signaling in trans complexes is altered. Complex formation in cis and trans was further studied in vivo by silencing NRP1 in the endothelium (using an inducible, endothelial-specific NRP1 knockout mouse model). Mice with or without endothelial NRP1 expression were subjected to tumor challenge. Remarkably, signaling in trans by tumor cells expressing NRP1 attenuated tumor growth in several models. A possible mechanism underlying the decreased tumor growth with NRP1 presentation in trans, is the different kinetics and distinct VEGF signaling. In conclusion, we show that NRP1 is essential for angiogenesis and suggest that VEGFdependent complex formation in trans by NRP1 and VEGFR2 may be negative regulator of VEGF signalling.

Aldehyde dehydrogenase activity earmarks cancer stem cells in endometrial cancer Marten van der Zee Josephine Nefkens Institute, Erasmus MC Cancer stem cells (CSCs) are considered to play key roles in the maintenance and malignant behavior of a broad spectrum of cancers. Moreover, they are thought to be resistant to conventional cytotoxic treatment and to underlie dissemination from the primary mass and the formation of distant metastases. Recently, it was found that patients with endometrial tumors that display high levels of aldehyde dehydrogenase (ALDH), a detoxifying enzyme found characteristic of many progenitor and stem cells, have a reduced survival when compared to patients with endometrial tumors with low ALDH levels. Based on this observation we hypothesized that ALDH activity could be used to enrich for CSCs in endometrial cancer. Here, we found that ALDH can be employed as a marker to enrich for CSCs in endometrial cancer cell lines and primary malignancies, as indicated by the


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increased tumor-initiating capacity of ALDHhi cells upon transplantation into immune deficient mice. Also, ALDHhi cells revealed increased clonogenicity and organoid-forming capacity when compared with the parental cell line and ALDHlow cells. Notably, the number of ALDHhi cells in both human endometrial cancer cell lines and primary human endometrial tumors inversely correlates with their differentiation grade. Gene expression analysis of ALDHhi vs. ALDHlow tumor cells revealed that the IL-6 receptor subunits CD126 and GP130 are differentially expressed (upregulated in ALDHhi). On the other hand, ALDHlow tumor cells express IL-6, i.e. the ligand for the CD126 and GP130 receptors. These results provide additional surface antigen markers to both improve endometrial CSC isolation and to allow their specific targeting towards the development of novel therapeutic strategies.

MGC Symposium Lecture Potentiating Signal-responsive Transcription: A Dynamic Dance Between Paused Polymerase and Chromatin Prof. dr. Karen Adelman Laboratory of Molecular Carcinogenesis, Research Triangle Park, USA RNA polymerase II (Pol II) transcription in metazoans is punctuated by promoter-proximal pausing, during which the polymerase begins RNA synthesis but then halts within the first 100 nucleotides. The stable pausing and regulated release of Pol II into productive elongation is increasingly recognized as an important checkpoint in gene expression, particularly in pathways involved in the responses to stimuli, development, and cell differentiation. However, important questions remain concerning the mechanisms underlying establishment vs. release of paused Pol II and the functional consequences of this mode of regulation. We have recently shown that a major role for the paused Pol II is to maintain accessible promoter chromatin around genes within stimulus-responsive pathways. Importantly, using models of development and immune responsiveness, we find that perturbations of pausing lead to defects in both basal and activated transcription that can be linked to disruption of chromatin architecture around key genes in these pathways.


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De MGC bestuurders en hun instituten Instituut Celbiologie  010-7043593 Erasmus Universiteit Rotterdam Postbus 2040, 3000 CA Rotterdam hoofd: Prof.dr. F.G. Grosveld (voorzitter MGC bestuur)

Centrum voor Humane en Klinische Genetica, LUMC  071-5269401 Postbus 9600, 2300 RC Leiden hoofd: Prof.dr. G.J.B. van Ommen (secretaris MGC bestuur)

Instituut Genetica  010-7043199 Erasmus Universiteit Rotterdam Postbus 2040, 3000 CA Rotterdam hoofd: Prof.dr. J.H.J. Hoeijmakers (lid MGC bestuur)

Afd. Toxicogenetica  071-5269603 Leids Universitair Medisch Centrum Postbus 9600, 2300 RC Leiden hoofd: Prof.dr. L.H.F. Mullenders (lid MGC bestuur)

LACDR/ Toxicology  071-5276223 Faculteit W&N, Universiteit Leiden Postbus 9502, 2300 RA Leiden hoofd: Prof.dr. B. van de Water (lid MGC bestuur)

Instituut Klinische Genetica  010-7043198 Erasmus Universiteit Rotterdam Postbus 2040, 3000 CA Rotterdam hoofd: Prof.dr. R.M.W. Hofstra (lid MGC bestuur)

Andere instituten/groepen binnen het MGC Moleculaire Celbiologie, LUMC: (Prof.dr. H.J. Tanke en Prof.dr. P. ten Dijke) Heelkunde, LUMC (Prof. Dr. R.A.E.M. Tollenaar) Neurologie, groep neurogenetica, LUMC (Prof.dr. R.A.C. Roos en Prof.dr. M.D. Ferrari) Huid- en geslachtsziekten, groep erfelijke melanomen, LUMC (Prof. R. Willemze, Prof.dr. W. Bergman, Dr. F. de Gruijl & Dr. N.A. Gruis) Pathologie: moleculaire tumorpathologie, LUMC (Prof.dr. P.C.W. Hogendoorn, Prof.dr. J. Morreau, Dr. A.M. Cleton-Jansen en Dr. J.V.M.G. Bovee) Medische Statistiek en Bio-informatica: Moleculaire epidemiologie, LUMC (Prof.dr. T. Stijnen en Prof.dr. P.E. Slagboom) Anatomie en Embryologie, LUMC (Prof.dr. C.L. Mummery) Projectgroep Biochemie van lipide metabolisme, LUMC (Prof.dr. Ir. L. Havekes) Instituut Pathologie, Oncogenengroep, ErasmusMC (Prof.dr. E.C. Zwarthoff) Instituut Pathologie, groep Fodde, ErasmusMC (Prof.dr. R. Fodde) Optical Imaging Centre (OIC), Department of Pathology, Erasmus MC (Prof. Dr. A. B. Houtsmuller) Kinderheelkunde, Ontwikkelingsbiologie groep, ErasmusMC (Prof.dr. D. Tibboel) Instituut Neurowetenschappen, ErasmusMC (Prof.dr. C.I. De Zeeuw) Epidemiologie en Biostatistiek, ErasmusMC (Prof.dr. C.M. van Duijn) Afd. Voortplanting en Ontwikkeling, ErasmusMC (Prof.dr. J.A. Grootegoed) Forensische Moleculaire Biologie, ErasmusMC (Prof.dr. M. Kayser) Bioinformatica, ErasmusMC (Prof.dr. P. van der Spek) Biochemie, ErasmusMC (Prof.dr. P. Verrijzer) [n.b. verbeteringen voor deze lijst gaarne doorgeven aan het secretariaat]

Het MGC secretariaat is gevestigd op de afdeling Toxicogenetica, Leiden.  071-5269600; Fax 071-5268284 Directie secretaris: Dr. M.J.M. Nivard  071-5269605 e-mail: [email protected]


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MGC-Bulletin, Nr. 47, September 2012 In dit nummer:

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