Combining mechanical and superresolution measurements to reveal the plasticity of the Nuclear Pore Complexes

 

Nuclear pore complexes (NPCs) are the only gateways between the nucleus and cytoplasm in eukaryotic cells, facilitating the transport of selected cargoes of size from a few up to hundred nanometers. This versatility implies an important pore plasticity. Here, by combining atomic force microscopy (AFM) and single molecule localization microscopy (SMLM), a group led by Christine Doucet and Pierre Emmanuel Milhiet from the IBM team revealed that the NPC basket is very soft and explores a large conformational landscape: apart from its canonical basket shape, it dives into the central pore channel or opens, highlighting how this structure can adapt, and let morphologically diverse cargoes shuttle through NPCs.

 

Publication
Structure and mechanics of the human nuclear pore complex basket using correlative AFM-fluorescence superresolution microscopy
Vial et al., Nanoscale, 15, 5756-5770 (2023)
https://pubs.rsc.org/en/content/articlepdf/2023/NR/D2NR06034E

 

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Phosphorylation motif dictates GPCR C-terminal domain conformation and arrestin interaction

 

Link to publication: 
https://www.sciencedirect.com/science/article/abs/pii/S0969212623002897?dgcid=author

The signaling pathways of arrestin-dependent G protein-coupled receptors (GPCRs) are regulated by the phosphorylation state of its C-terminal domain. The molecular basis of the arrestin-receptor interaction is not fully understood. In this study, we investigated the impact of phosphorylation on the conformation of the C-terminal region of three rhodopsin-like GPCR (V2R, GHSR, and β2AR). Using phosphomimetic models, the team of Nathalie Sibille, in collaboration with the team of Jean-Louis Banères (IBMM), has identified pre-formed secondary structure elements, or short linear motifs (SLiMs), that undergo specific conformational transitions upon phosphorylation. It's important to note that such conformational transitions occur in the region interacting with arrestin-2. Thus, our results suggest a model in which the phosphorylation-dependent conformation of the C-terminal regions of GPCRs would modulate arrestin binding and consequently the signaling of arrestin-dependent pathways. This illuminates how signaling through GPCRs in the arrestin-dependent pathway could proceed, further paving our understanding of this central process in cell-cell communication.

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The “Impulscience” prize awarded to Ashley Nord

The Impulscience® program aims to reward and support excellent researchers in France, and to strengthen the attractiveness of France as a place of research to retain its talents and attract others. It meets two imperatives: preserving the freedom of innovation for researchers and supporting them over time.
Ashley Nord, CNRS biophysics researcher in the “Physics and mechanics of biological systems” Team at the CBS is one of the 7 winners this year. By studying the formation of bacterial biofilms through the prism of physical, it aims to radically disrupt everything that what we knew about them until now.

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Multi-scale dynamic imaging reveals that cooperative motility behaviors promote efficient predation in bacteria

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Overlay of Myxococcus xanthus bacteria trajectories
during the invasion of an Escherichia coli colony.

 

Publication link:
Rombouts, S., Mas, A., Le Gall, A. Fiche, J.B., Mignot, T., Nollmann, M.. Multi-scale dynamic imaging reveals that cooperative motility behaviors promote efficient predation in bacteria. Nat Commun 14, 5588 (2023). https://doi.org/10.1038/s41467-023-41193-x

 

Video: “Synchronized synergy: collective movement in Myxococcus xanthus”
https://www.wibbitz.com/watch/b603898e8c7d54592955b58828cb8d349/?cl=#5c6168&cl4=%2315324e&lg=8132e369779d4f878702ab25f531c8cf&type=produced

 

Abstract
Many species, such as fish schools or bird flocks, rely on collective motion to forage, prey, or escape predators. Likewise, Myxococcus xanthus forages and moves collectively to prey and feed on other bacterial species. These activities require two distinct motility machines enabling adventurous (A) and social (S) gliding, however when and how these mechanisms are used has remained elusive. Here, we address this long-standing question by applying multiscale semantic cell tracking during predation. We show that: (1) foragers and swarms can comprise A- and S-motile cells, with single cells exchanging frequently between these groups; (2) A-motility is critical to ensure the directional movement of both foragers and swarms; (3) the combined action of A- and S-motile cells within swarms leads to increased predation efficiencies. These results challenge the notion that A- and S-motilities are exclusive to foragers and swarms, and show that these machines act synergistically to enhance predation efficiency.

Le Centre de Biologie Structurale (CBS) de Montpellier s’engage à accueillir 6 stagiaires de seconde générale et technologique, du 17 au 28 juin 2024

STAGES de SECONDE

Le Centre de Biologie Structurale (CBS) de Montpellier s’engage à accueillir 6 stagiaires de seconde générale et technologique, du 17 au 28 juin 2024.

Durant les 2 semaines passées au laboratoire, les stagiaires répartis en binômes alterneront entre des ateliers de découverte dans différentes disciplines (biologie moléculaire et cellulaire, biochimie, microscopie, biophysique…) et des journées d’observation auprès du personnel exerçant différents métiers de la recherche. A l’issue du stage, les élèves devront réaliser et présenter un poster en lien avec l’une des thématiques scientifiques abordées lors du stage.

Ces stages s’adressent en priorité à des élèves de seconde, s'engageant dans des spécialités scientifiques en première et terminale. Les demandes doivent etre adressées exclusivement via le formulaire:

https://docs.google.com/forms/d/e/1FAIpQLSeZOCBlIV1QPZcAa-5NFVG7PI5CcAEY2cFENcIItx1lbKwvzw/viewform?usp=sf_link

En complément, un CV et une lettre de motivation devront être envoyés à l'adresse This email address is being protected from spambots. You need JavaScript enabled to view it. avant le 31 mars 2024 (fichier pdf unique au nom du candidat). Une sélection sera effectuée sur la base de ce dossier. Nous serons aussi particulièrement attentifs à la parité et une liste d’attente sera établie pour pallier tout désistement. Les réponses seront données aux élèves le 5 avril 2024

Il est recommandé de rechercher un autre stage dans l’éventualité où votre candidature ne serait pas retenue.

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