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Denis Chrétien

@dchretien.bsky.social
508 followers 1.1K following 96 posts

Microtubule and cryo-ET addict!

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Reposted by Denis Chrétien
Rémi Fronzes @fronzeslab.bsky.social · 29/09/2026
CryoFIB SEM installed at the @bic-bordeaux.bsky.social 🍾🎉🍾🎉
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Reposted by Denis Chrétien
McGill University @mcgill.ca · 14/09/2026
Meet the Titan Krios 300 kV cryo-EM. 🔬 One of only 3 in Canada, this towering 4.5 m microscope reveals highly accurate structures of cells, proteins and more. A key tool for advancing medical research. 📷 Nature Index, Integrated Structural Biology Grenoble (ISBG)
A McGill researcher wearing a white lab coat operates a Titan Krios cryo-electron microscope in a laboratory. The instrument’s access door is open, revealing internal components, with a computer workstation visible in the background.Close-up view of the internal components of a Titan Krios cryo-electron microscope. The image shows a complex assembly of metallic cylinders, cables, sensors, and electronic components mounted within the instrument’s chamber, illuminated by blue and white lighting.
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Reposted by Denis Chrétien
Ben Engel @cellarchlab.com · 08/09/2026
MemBrain v2 is on @natmethods.nature.com now? I never had a @biorxivpreprint.bsky.social with 164 citations before😅 ...Which is also to say: Thank you to the amazing #TeamTomo community, many of whom not only beta tested, but also contributed diverse training data. This one belongs to all of us! 🤗🔬🧪
BioRxiv FTW
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Reposted by Denis Chrétien
CNRS Biologie @cnrsbiologie.bsky.social · 07/09/2026
#ResultatScientifique🔎| L’attention adaptative au bruit : clé d’une segmentation robuste des microtubules en microscopie ✍️ @bouvraish.bsky.social 🔬 @igdrennes.bsky.social 👋 @cnrs-bretagneloire.bsky.social @rennesuniv.bsky.social buff.ly/EOhBolv
insb.cnrs.fr
L’attention adaptative au bruit : clé d’une segmentation robuste des microtubules en microscopie
Les 'squelette
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Reposted by Denis Chrétien
Institut Jacques Monod @ijmonod.bsky.social · 01/09/2026
📣Paris Cytoskeleton Day - Registrations are open! 📅 November, 24th 📍Institut Jacques Monod Abstract submission closes on 2 November Registration closes on 16 November 🔗 pcd2026.sciencesconf.org
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Denis Chrétien @dchretien.bsky.social · 28/08/2026
Dear #CryoEM and #Microtubule enthusiasts, I’m thrilled to have been part of this exciting journey: www.biorxiv.org/content/10.6... We discovered and characterized a manchette-like microtubule machinery in Xenopus spermatids, likely involved in sperm reshaping and membrane reorganization. (1/3)
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Denis Chrétien @dchretien.bsky.social · 27/08/2026
Dear #Cryo-EM and #Microtubule lovers. TubulePy is online at github.com/dchretien35/... TubulePy allows calculation of microtubule protofilament skew angles (θ) and helical parameters for different protofilament numbers (N) and helical-start numbers (S). (1/2).
github.com
GitHub - dchretien35/TubulePy: TubulePy allows calculation of microtubule helical parameters to built models from PDB files.
TubulePy allows calculation of microtubule helical parameters to built models from PDB files. - dchretien35/TubulePy
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Denis Chrétien @dchretien.bsky.social · 16/08/2026
Thanks for advancing the field! It's very nice to make these softs at the disposal of the cryo-EM/Microtubule community ;-)
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Reposted by Denis Chrétien
EMBL Events @events.embl.org · 22/06/2026
#EESMicrotubules brought together an amazing community of microtubule researchers last week 🥼 Thank you to our wonderful participants, speakers, and organisers for 4 days of outstanding science and thought-provoking discussions! We hope to see you again at the next edition.
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Denis Chrétien @dchretien.bsky.social · 03/07/2026
In situ structural biology: bridging molecular mechanisms with system-wide approaches www.embl.org/about/info/c...
embl.org
In situ structural biology: bridging molecular mechanisms with system-wide approaches
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Reposted by Denis Chrétien
Direct Electron @directelectron.bsky.social · 02/07/2026
More throughput. More particles. More structures. On a JEOL CRYO ARM 300 II, Apollo sustained 1,820 movies/hour across a complete cryo-EM dataset—collecting over 500,000 particles and reconstructing apoferritin to 1.72 Å in a single afternoon. Read how: ow.ly/kEYn50ZjOFX
ow.ly
HIGH-THROUGHPUT CRYO-EM WITH APOLLO - Direct Electron
Up to 2,904 movies per hour and sustained 1,820 movies per hour, reconstructing apoferritin at 1.72 Å in a single afternoon.
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Reposted by Denis Chrétien
Lena Schindler @lena-schindler.bsky.social · 23/06/2026
I am thrilled to share my PhD work with @nicolettapetridou.bsky.social @embl.org: www.biorxiv.org/cgi/content/... A fun collaboration with Bernat Corominas-Murtra, Adrián Aguirre-Tamaral, @bart-smeets.bsky.social , Jef Vanghel and Tom Belpaire! Read the story in the comments below ⤵️
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Denis Chrétien @dchretien.bsky.social · 23/06/2026
Well done. But is GTP-tubulin in an expanded state at the tip of growing microtubules? Indeed, nobody knows 🤔
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Reposted by Denis Chrétien
GIS IBiSA @ibisa.net · 15/06/2026
La #plateforme TEM2C de l'UAR Biosit propose ses services en cryo-microscopie électronique, cryo-tomographie et cryo-CLEM pour la biologie structurale et cellulaire ➡️ www.ibisa.net/plateformes-... @cnrsbiologie.bsky.social @inserm.fr @rennesuniv.bsky.social
ibisa.net
Transmission electron microscopy, cryo and CLEM (TEM2C)
Approches intégrées de cryo-microscopie électronique, cryo-tomographie et cryo-CLEM pour la biologie structurale et cellulaire.
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Denis Chrétien @dchretien.bsky.social · 13/06/2026
Nice story 😎
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Denis Chrétien @dchretien.bsky.social · 10/06/2026
So lovely 😍
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Reposted by Denis Chrétien
Eugene Katrukha 🇺🇦 @ekatrukha.bsky.social · 31/03/2026
The new release of #BigVolumeBrowser (0.1.0) finally adds animation render functionality to it, plus some other navigation improvements and bug fixes. Here is a movie I've made for the microtubule network (via ExM) in different cell types. Contact me if you want it for educational/research purposes.
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Reposted by Denis Chrétien
Leah @hoxinsocks.bsky.social · 31/05/2026
I love us
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Denis Chrétien @dchretien.bsky.social · 27/05/2026
Looks cool, will try!
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Reposted by Denis Chrétien
RCSB Protein Data Bank @rcsbpdb.bsky.social · 16/05/2026
Try this new online training game from Leandro F. Estrozi designed for newcomers in structural biology, with a focus on cryo-EM and cryo-ET map interpretation: rico.ibs.fr/helixplo...
Screenshot of online game
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Reposted by Denis Chrétien
Christophe 🔬 Leterrier @christlet.bsky.social · 13/05/2026
Check the little video they made from the interview (with the “Rolex” Rave skateboards tee-shirt 😆)
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Reposted by Denis Chrétien
Royal Microscopical Society @royalmicrosoc.bsky.social · 12/05/2026
We are very pleased to announce Prof. Paul Guichard and Dr. Virginie Hamel @centriolelab.bsky.social as joint winners of the RMS Award for Light Microscopy 🔬 👏 🏅 Huge congratulations to both! Read more about Paul and Virginie's achievements: www.rms.org.uk/resource/pro...
Prof. Paul Guichard (left) and Dr. Virginie Hamel both pictured smiling against a plain background. Head and shoulders images.
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Denis Chrétien @dchretien.bsky.social · 12/05/2026
Great discovery from Manuel Thery, even the Musée d'Orsay has a cytoskeleton 😍
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Reposted by Denis Chrétien
Aryan Taheri @aryantaheri.bsky.social · 08/05/2026
How do #tubulin dimers assemble and disassemble to form the #microtubule #cytoskeleton? Our recent #cryo-EM structures, published in #ScienceAdvances, demonstrate the processes of tubulin biogenesis and degradation. Click on the video and link below to learn more! www.science.org/doi/10.1126/...
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Denis Chrétien @dchretien.bsky.social · 06/05/2026
You loved the A- and B-type lattices in microtubules? Discover the C- and D-types specific to the GTP-like state of tubulin during the talk of Matthieu Benoit, 8th May, 10:30 warwick.ac.uk/fac/sci/med/... #microtubule #tubulin #CryoEM
warwick.ac.uk
Motors and Filaments
Mechanochemistry of molecular motors and cytoskeletal filaments - a scientific meeting at the University of Warwick
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Denis Chrétien @dchretien.bsky.social · 06/05/2026
The full EMBO microtubule program is now online 🤩 Note the talk of Celine Callens from our lab presenting the discovery and structural characterization of internal proteins within Xenopus spermatid microtubules on Thursday, 10:40 😍 www.embl.org/about/info/c... #microtubule #CryoEM
embl.org
Microtubules: from atoms to complex systems
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Reposted by Denis Chrétien
SBCF @sbcf.bsky.social · 04/05/2026
Ready for #CellLaVie2026? Program & registration are live! Join us Oct 21–23, 2026 at Institut Pasteur, Paris, for multidisciplinary cell biology, imaging, talks, posters & outreach, w/ Manuel Théry's behind-the-scenes look at the Musée d’Orsay video-mapping project. www.atoutcom.com/cell-la-vie/
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Reposted by Denis Chrétien
Anne Straube @anne.mechanochemistry.org · 01/05/2026
Barely a week to go until our "Motors and Filaments" meeting. Programme is ready. Catering ordered. My 3d printer has been busy too: have a look into the mingle bingo and dinner quiz prizes box. tinyurl.com/mechanochemi...
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Reposted by Denis Chrétien
Alexis Verger 🧬🧫🧪 @alexis-verger.cpesr.fr · 30/04/2026
#ESR Faudra-t-il en arriver là pour financer la recherche ? youtu.be/x2XMfjfG2ug?...
youtu.be
ICM - Le strip-tease
YouTube video by Publicis Conseil
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Reposted by Denis Chrétien
Alex Merz 🇺🇸🇨🇦🇺🇦 @merz.bsky.social · 23/04/2026
Vaults are still among the most mysterious of all structures found in eukaryotes. This is extremely cool and unexpected.
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Quanta Magazine @quantamagazine.org · 20/04/2026
A powerful electrical motor propels bacteria in virtually every gut and puddle on Earth. After 50 years, it has finally been understood. @nattyover.bsky.social reports: www.quantamagazine.org/what-physica...
quantamagazine.org
What Physical ‘Life Force’ Turns Biology’s Wheels? | Quanta Magazine
The bacterial flagellar motor is finally understood after 50 years. In its workings, columnist Natalie Wolchover finds the essence of life.
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Denis Chrétien @dchretien.bsky.social · 14/04/2026
Stunning 😍, congrats!!!
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Reposted by Denis Chrétien
Bui Lab @McGill @builab.bsky.social · 12/04/2026
The cartwheel was first visualized ~70 years ago in the symbiont Trichonympha in the wood termite gut. We’ve discovered the cartwheel’s secret: a unique zigzag stacking of SAS-6 tetramers that facilitates the iconic 9-fold symmetry of cilia. #cellbiology #teamtomo #SAS6 #cartwheel
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Denis Chrétien @dchretien.bsky.social · 11/04/2026
Beautiful work 😍
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Denis Chrétien @dchretien.bsky.social · 11/04/2026
A very nice study showing that there is no obvious relationship between tubulin compaction/expansion state and its nucleotide state. Indeed, there is no experimental data demonstrating that GTP-tubulin is expanded in the GTP-cap at microtubule growing ends.
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Reposted by Denis Chrétien
Caitie McCafferty @computingcaitie.bsky.social · 08/04/2026
I am excited to share our most recent work collaborating with @centriolelab.bsky.social and @stearnslab.bsky.social to look at the ciliary base of mammalian multiciliated cells w/ cryo-ET, XL/MS, and U-ExM www.biorxiv.org/content/10.6...
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Denis Chrétien @dchretien.bsky.social · 03/04/2026
Opening of our JEOL Cryo-ARM 200, 2 April 2026 :-) Don't hesitate to get in touch with us if you want nice cryo-EM and/or cryo-ET data ! biosit.univ-rennes.fr/en/tem2c #cryo-EM #microtubule
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Benoît Zuber @benoitzuber.bsky.social · 30/03/2026
New paper in Nature Communications: we identified ANTXR2 (CMG2) as the cellular receptor for C. perfringens NetF toxin, causing hemorrhagic enteritis in dogs and foals. ANTXR2 was previously known as the receptor for anthrax toxin PA. doi.org/10.1038/s414...
doi.org
Identification and structural characterization of anthrax toxin receptor 2 as the Clostridium perfringens NetF receptor - Nature Communications
This study identifies ANTXR2 as the cellular receptor for Clostridium perfringens toxin NetF and determines its structure bound to the toxin using cryo-EM, revealing a distinct lateral binding mechani...
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Leah Lavery @helloleahlavery.bsky.social · 23/03/2026
Congratulations to Dr. Julia Mahamid on receiving the 2026 Gottfried Wilhelm Leibniz Prize! 🎉 Her pioneering work in cryo-ET is reshaping our understanding of how molecular architecture drives cellular processes and disease. #teamtomo #LeibnizPrize #StructuralBiology #LifeSciences #Innovation
dfg.de
Julia Mahamid, Ph.D. – Gottfried Wilhelm Leibniz Prizewinner 2026
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Carter Lab @carter-lab.bsky.social · 24/03/2026
Excited to share our work on the structure and function of cytoplasmic lattices within mouse embryos. A collaborative effort with @niakanlab.bsky.social and work led by @kashishsingh.bsky.social and @inaharasimov.bsky.social . It is now out on BioRxiv: www.biorxiv.org/content/10.6...
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Anne Straube @anne.mechanochemistry.org · 25/02/2026
The abstract deadline for our Motors and Filaments Meeting is approaching fast - 1st March. We have plenty slots for 15/10min talks and 3min flash talks to allocate. Thanks to generous support from @embo.org and @biologists.bsky.social, we can offer sustainable travel bursaries and a free livestream
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Vladimir Volkov 🇺🇦 @vladimirvolkov.bsky.social · 20/03/2026
Happy to see the first paper from the lab published in the EMBO J today: link.springer.com/article/10.1... In it, we reconstitute self-assembling cooperative oligomers of human Ndc80 and Ska kinetochore complexes that stabilise microtubule ends, and study these samples using cryoET and TIRF
link.springer.com
Microtubule end stabilisation by cooperative oligomers of Ska and Ndc80 complexes - The EMBO Journal
During mitosis, properly aligned chromosomes stabilise microtubule ends with the help of kinetochores to ensure timely segregation of chromosomes. Microtubule-binding components of the human outer kin...
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Journal of Cell Science @jcellsci.bsky.social · 19/03/2026
Cordula Reuther, Paula Santos-Otte, Stefan Diez and colleagues find that microtubule lattice defects facilitate spastin-mediated severing. journals.biologists.com/jcs/article/... #OpenAccess #ReadandPublish
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Atherton Lab KCL @athertonlabkcl.bsky.social · 07/07/2025
Excited to see our @natcomms.nature.com paper out! #Cryo-EM reveals a #microtubule stimulated ADP-release transition state of #kinesin 1. The auto-inhibitory tail has no affect on motor domain conformations. Focussed subunit processing helps! #cryoEM #microtubules www.nature.com/articles/s41...
nature.com
Microtubule association induces a Mg-free apo-like ADP pre-release conformation in kinesin-1 that is unaffected by its autoinhibitory tail - Nature Communications
Kinesin-1 utilizes ATP-driven conformational changes to transport vital intracellular cargoes along microtubules. The authors use cryo-EM to reveal a missing structural transition state of the kinesin...
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Denis Chrétien @dchretien.bsky.social · 13/03/2026
Microtubules: from atoms to complex systems www.embl.org/about/info/c... Deadline extended to 18 March See you there :-) #microtubules
embl.org
Microtubules: from atoms to complex systems
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EMBL Events @events.embl.org · 11/03/2026
Join #EMBOCryoEM to get a comprehensive foundation in advanced single-particle and cellular tomography techniques – we'll cover the entire workflow from sample preparation to data collection and image processing. s.embl.org/cry26-01-bl Apply by: 11 May 2026 @embo.org
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Aritz Roa-Eguiara @aritz-roa.bsky.social · 07/03/2026
🚨Preprint! Happy to share the research from my PhD “Genome delivery of a contractile tailed phage and its superinfection exclusion mechanism”. We use cryoEM to study the genome ejection of the phage T4, revealing how the tape measure protein regulates the process. www.biorxiv.org/content/10.6...
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Simone Reber @simonereber.bsky.social · 06/03/2026
In vitro reconstitution is powerful: we can rebuild Plasmodium microtubule architectures from purified components and recapitulate what cells actually do 🤩 Thanks to an incredible team that made this possible 🙌 @carolynmoores1.bsky.social in particular rdcu.be/e7eM2
rdcu.be
Adaptations in Plasmodium tubulin determine distinct microtubule architectures, mechanics and drug susceptibility
Nature Communications - Tubulin conservation presents a challenge to understanding microtubules’ diverse functions in eukaryotes. Here, the authors characterize the structures of P....
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Denis Chrétien @dchretien.bsky.social · 26/02/2026
A cryo-EM processing pipeline for microtubules using CryoSPARC www.biorxiv.org/content/10.6... #CryoEM, #microtubule
biorxiv.org
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sdvupsaclay.bsky.social @sdvupsaclay.bsky.social · 22/02/2026
FOCUS PLATEFORME : La plateforme de Cryo-Microscopie Électronique I2BC accueille Heddy Soufari, ingénieur-chercheur CEA, pour renforcer le développement méthodologique en cryo-EM
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FOCUS PLATEFORME : La plateforme de Cryo-Microscopie Électronique I2BC accueille Heddy Soufari, ingénieur-chercheur CEA, pour renforcer le développement méthodologique en cryo-EM
La plateforme conjointe de Cryo-Microscopie Électronique de l’Institut de Biologie Intégrative de la Cellule (I2BC, Gif-sur-Yvette, Institut Joliot, CEA, Saclay) et du Synchrotron SOLEIL renforce son expertise avec l’arrivée de Heddy Soufari, recruté en tant qu’ingénieur-chercheur CEA. Spécialisé en biologie structurale et en cryo-microscopie électronique (cryo-EM), il consacre l’essentiel de son activité au développement méthodologique et au soutien scientifique des utilisateurs régionaux et nationaux sur les sites de SOLEIL et de l’I2BC.   Docteur en biologie structurale de l’Université de Bordeaux, Heddy Soufari a orienté ses recherches vers la compréhension de la structure et de la dynamique des complexes macromoléculaires. Après un parcours académique entre la France et le Canada, il a acquis une solide expertise en cryo-microscopie électronique appliquée à l’étude de systèmes biologiques complexes. Il a notamment contribué à la caractérisation de ribosomes de mitochondries et de complexes protéiques chez différents modèles eucaryotes, avant de rejoindre la société NovAliX où il dirige le pôle Cryo-EM et met la microscopie au service du structure-based drug design (SBDD) sur des cibles thérapeutiques.   Depuis son recrutement au CEA en septembre 2024, il accompagne les chercheurs de l’I2BC et de la région dans leurs projets de cryo-EM, de la préparation d’échantillons à l’analyse des reconstructions tridimensionnelles. Il développe parallèlement une activité méthodologique centrée sur la cryo-tomographie électronique (cryo-ET) et l’imagerie corrélative cryo-CLEM, avec pour objectif d’étudier l’organisation et la dynamique de complexes macromoléculaires in situ. Sa vision scientifique repose sur une approche multi-échelle, allant de la molécule unique à la cellule entière, afin d’explorer la tridimensionnalité des systèmes biologiques dans toute leur complexité.   Avec l’arrivée d’Heddy Soufari, la plateforme renforce sa capacité à développer de nouvelles méthodologies et pipelines pour la tomographie cellulaire, l’analyse d’images 3D et la corrélation optique-électronique. Ces efforts visent à faire de la plateforme un pôle de référence pour la visualisation in situ des architectures cellulaires et des complexes macromoléculaires à haute résolution.   -> Contact : Stéphane Bressanelli (plt-cryoem@i2bc.paris-saclay.fr)   Plug In Labs Université Paris-Saclay : cliquer ICI   Envie de (re)lire leurs précédents FOCUS PLATEFORME ? 17 février 2020 FOCUS PLATEFORME : Des analyses par cryo-microscopie électronique révèlent les mécanismes d'auto-assemblage de l'α-synucléine, une protéine impliquée notamment dans la maladie de Parkinson 4 décembre 2023 FOCUS PLATEFORME : Un assemblage protéique à façon visualisé par cryo-microscopie électronique et reconstruction 3D   I2BC / Plateforme de cryo-microscopie électronique (CRYO-EM). La plateforme pour la cryo-microscopie électronique I2BC met à disposition une large gamme d’instruments et de services pour la biologie structurale : vitrification d’échantillons (Vitrobot, Leica GP2), microscope Tecnai Spirit (120 kV) pour les expériences préliminaires, microscopes de dernière génération Glacios (200 kV) pour les expériences à haute résolution, ainsi qu’un microscope confocal cryogénique Stellaris pour les approches corrélatives optique-électronique. La plateforme a la capacité de préparer et d’imager des échantillons biologiques de niveau de sécurité 2. Elle s’est associée au mésocentre de calcul Paris-Saclay pour l’hébergement des serveurs de stockage et d’analyse des images produites. La plateforme CryoEM de l’I2BC est associée à SOLEIL dans le cadre de la plateforme conjointe CryoEM@Paris-Saclay. Les images obtenues en cryo-microscopie électronique sur le microscope Glacios, ainsi que les moyens de calcul disponibles sur la plateforme, permettent le crible de grilles et la détermination de structures 3D à des résolutions dépassant fréquemment 3 Å et pouvant atteindre 2 Å. Ces premières structures permettent si nécessaire d'accéder aux microscopes plus puissants, notamment le Titan Krios G4 (300 kV) à SOLEIL, mais aussi les microscopes Titan Krios de l'ESRF, de l’IBS (Grenoble) ou de l'IGBMC (Strasbourg), menant aux résolutions atomiques. La plateforme CryoEM de l’I2BC permet aussi l'observation de complexes in situ (protéines à la surface d'organites purifiés ou de virus enveloppés, protéines membranaires reconstituées dans des liposomes...) par cryo-tomographie électronique. La plateforme accueille des projets issus de la recherche académique, institutionnelle et industrielle, et s’inscrit dans le réseau des infrastructures nationales en biologie structurale et intégrative (FRISBI). Ses missions couvrent la préparation d’échantillons, la collecte de données, le traitement d’images, la formation et l’accompagnement des utilisateurs. Cette plateforme fait partie du pôle des plateformes de Biologie Structurale de l'I2BC qui comprend six plateformes : cristallographie, RMN, CryoEM, mesures d'interactions macromoléculaires (PIM), expression de protéines recombinantes en systèmes eucaryotes (Prot-Ex) et sélection sur mesure de protéines artificielles comme ligands spécifiques de toute protéine d’intérêt (AlphaRep). D’autre part, les plateformes CryoEM, cristallographie, PIM et AlphaRep sont aujourd’hui labélisées IBISA sous la bannière BioStruct@UPSAY.   A propos de l’Institut de Biologie Intégrative de la Cellule (I2BC - UMR 9198). L’I2BC est une Unité Mixte de Recherche (CEA, CNRS, Université Paris-Saclay), accueillant une soixantaine d’équipes de recherche et hébergeant 17 plateformes technologiques, réparties en 6 pôles. 2025 a aussi été une année clé pour l’I2BC : cette unité a fêté ses 10 ans !
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