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Mai 2022



Salle Condorcet

Séminaire Externe

« Cytoplasmic forces organize the oocyte nucleus across scales »

Marie-Hélène VERLHAC  (Collège de France, Paris)
Contact : Gael Yvert

The Terret/Verlhac lab uses interdisciplinary approaches (biophysics, imaging and more) to study how mouse oocytes get organized for meiotic divisions and early embryogenesis. You can learn about her research here:

Lundi 02/05/2022


Séminaire Externe

« Anatomy of icosahedral capsids: from structure to function »

Mihnea BOSTINA Laboratory of Microbiology & Immunology, University of Otago , New Zealand)                       
Host : Patrice Gouet & Christophe Grangeasse
Viruses are capable to precisely assemble complex icosahedral capsids of hundreds or thousands of copies of just a few viral proteins. I will present a gallery of structures of viral capsids with different triangulation (T) numbers, sizes, composition, and origin. I will start with small picornaviruses (T=1) via a series of bacteriophages of increasing dimensions to a large iridovirus (T=147). Finally, I will illustrate how the structure of Seneca Valley Virus, a picornavirus with oncolytic properties, explains its specific tropism for cancer cells.

Vendredi 06/05/2022

Salle des Thèses CRC

Séminaire Externe

« Regulation of large-scale chromatin architecture in mammalian cells »

 Nick GILBERT (Professor of Chromatin Biology, Medical Research Council Human Genetics Unit at the University of Edinburgh)
Contact : V. Vanoosthuyse
Mammalian transcripts are processed to form abundant chromatin-associated RNAs (caRNA) with a half-life of 60 min; they interact with HNRNPU (also called SAF-A, scaffold attachment factor A) to create a protein/RNA mesh (1) that regulates large-scale chromatin structures (2). Using super-resolution microscopy we show this mesh forms a net comprised of 80-nm SAF-A clusters interacting with thread-like filaments, separating transcriptionally active regions from the nucleoplasm. Transcription inhibition, triggering caRNA degradation, causes the mesh to collapse, compacting chromatin, and is re-created by polymer model simulations. Under normal conditions the caRNA mesh is rapidly turned over by XRN2, a HNRNPU interacting protein. XRN2 depletion maintains caRNA levels, even after transcription inhibition, and retains chromatin in a decompacted configuration. However, loss of XRN2 and a build-up of caRNA triggers a DNA damage response. Surprisingly, caRNA degradation by XRN2 sustains the ribonucleotide pool, and in its absence causes transcription inhibition. For the first time we show that caRNAs both perform a structural role regulating chromosome structure but are also recycled by XRN2, linking together chromatin architecture and transcriptional regulation.

(1) Marenda M, Lazarova E, van de Linde S, Gilbert N, Michieletto D. Parameter-free molecular super-structures quantification in single-molecule localization microscopy. J Cell Biol. 2021 220(5):e202010003.
(2) Nozawa RS, Boteva L, Soares DC, Naughton C, Dun AR, Buckle A, Ramsahoye B, Bruton PC, Saleeb RS, Arnedo M, Hill B, Duncan RR, Maciver SK, Gilbert N. SAF-A Regulates Interphase Chromosome Structure through Oligomerization with Chromatin-Associated RNAs. Cell. 2017 169:1214-122

Lundi 09/05/2022


Salle Condorcet

Séminaire Externe


Host : Marie-Cecile Caillaud

Mardi 10/05/2022



Séminaire externe

 « Culturing Hepatitis E Virus– recent advances and novel perspectives for basic science and drug discovery »

Eike STEINMANN (Molecular and Medical Virology, Ruhr-University Bochum, Germany)
Contact: Marlène Dreux
Hepatitis E virus is the leading cause of liver cirrhosis and liver failure with increasing prevalence worldwide. The single-stranded RNA virus is predominantly transmitted by blood transfusions, inadequate sanitary conditions and contaminated food products. To date the off-label drug ribavirin (RBV) is the treatment of choice for many patients. Nonetheless, a specific HEV treatment remains to be identified. So far, the knowledge about the HEV life cycle and pathogenesis has been severely hampered because of the lack of an efficient HEV cell culture system. In this presentation a method and its characterization will be presented to produce high titers of non-enveloped and enveloped HEV particles. Using this cell culture system, different novel findings with respect to HEV entry, replication and assembly as well as drug design strategies will be shown.

Jeudi 19/05/2022


Amphi Pasteur

Séminaire externe

 « Supramolecular assemblies in the immunological synapse »

MICKAEL DUSTIN (Institut Kennedy à Oxford)
Contact: Antoine Marçais & Marlène Dreux
In this talk I will provide a historical background on immunological synapses and then discuss three ongoing stories. We started our analysis of supramolecular assemblies in the immunological synapse through study of CD4 helper T cells- first looking at signaling through antigen receptors and then the fate of those receptors in extracellular vesicles created by T
cell at the synaptic interface to coordinate immune responses. We next adapted our technology to investigated how CD8 cytotoxic T cells and NK cells us supramolecular assemblies to kill infected and cancerous cells. Which cytotoxic mechanisms are deployed is
tactical and basic on what target-associated receptors are discovered by the T cell. FAS on targets triggered extracellular vesicles with FasL to trigger target suicide, whereas 100 nm protein “bombs” with a core of cytotoxic perforin and granzymes and a shell of
thrombospondin-1 were deployed when the target expressed ICAM1 or CD47. We refer to these protein bombs as supramolecular attack particles and these have potential as novel therapeutics. Finally, I will discuss how malaria parasites use some members of a large family of proteins called RIFINs to inhibit attack by innate natural killer (NK) cells-creating an inhibitory immunological synapse to protect parasitized red blood cells. In order to defeat this mechanism, the host makes extraordinary antibodies that incorporate entire RIFIN targets into antibody V-regions

Lundi 30/05/2022


Salle de conférence IBCP

Séminaire externe

« Mechanism of acquisition of the Cholera Toxin genes by Vibrio cholerae »

François-Xavier BARRE (I2BC, gif-sur-Yvette)           
Host : S. Bigot











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