UMR168 – Laboratoire Physico-Chimie Curie

Publications de l’UMR 168

Année de publication : 2021

Kaushik Inamdar, Feng-Ching Tsai, Rayane Dibsy, Aurore de Poret, John Manzi, Peggy Merida, Remi Muller, Pekka Lappalainen, Philippe Roingeard, Johnson Mak, Patricia Bassereau, Cyril Favard, Delphine Muriaux (2021 Jun 11)

Full assembly of HIV-1 particles requires assistance of the membrane curvature factor IRSp53.

eLife : DOI : 10.7554/eLife.67321 En savoir plus
Résumé

During HIV-1 particle formation, the requisite plasma membrane curvature is thought to be solely driven by the retroviral Gag protein. Here, we reveal that the cellular I-BAR protein IRSp53 is required for the progression of HIV-1 membrane curvature to complete particle assembly. siRNA-mediated knockdown of IRSp53 gene expression induces a decrease in viral particle production and a viral bud arrest at half completion. Single-molecule localization microscopy at the cell plasma membrane shows a preferential localization of IRSp53 around HIV-1 Gag assembly sites. In addition, we observe the presence of IRSp53 in purified HIV-1 particles. Finally, HIV-1 Gag protein preferentially localizes to curved membranes induced by IRSp53 I-BAR domain on giant unilamellar vesicles. Overall, our data reveal a strong interplay between IRSp53 I-BAR and Gag at membranes during virus assembly. This highlights IRSp53 as a crucial host factor in HIV-1 membrane curvature and its requirement for full HIV-1 particle assembly.

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Daniel Lévy, Aurélie Di Cicco, Aurélie Bertin, Manuela Dezi (2021 Jun 7)

[Cryo-electron microcopy for a new vision of the cell and its components]

Medecine/Sciences : 379-385 : DOI : 10.1051/medsci/2021034 En savoir plus
Résumé

Cryo-electron microscopy (cryo-EM) is a technique for imaging biological samples that plays a central role in structural biology, with high impact on research fields such as cell and developmental biology, bioinformatics, cell physics and applied mathematics. It allows the determination of structures of purified proteins within cells. This review describes the main recent advances in cryo-EM, illustrated by examples of proteins of biomedical interest, and the avenues for future development.

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Eugenio de la Mora, Manuela Dezi, Aurélie Di Cicco, Joëlle Bigay, Romain Gautier, John Manzi, Joël Polidori, Daniel Castaño Díez, Bruno Mesmin, Bruno Antonny, Daniel Lévy. (2021 Jun 7)

Nanoscale architecture of a VAP-A-OSBP tethering complex at membrane contact sites

Nature Communications : DOI : 10.1038/s41467-021-23799-1 En savoir plus
Résumé

Membrane contact sites (MCS) are subcellular regions where two organelles appose their membranes to exchange small molecules, including lipids. Structural information on how proteins form MCS is scarce. We designed an in vitro MCS with two membranes and a pair of tethering proteins suitable for cryo-tomography analysis. It includes VAP-A, an ER transmembrane protein interacting with a myriad of cytosolic proteins, and oxysterol-binding protein (OSBP), a lipid transfer protein that transports cholesterol from the ER to the trans Golgi network. We show that VAP-A is a highly flexible protein, allowing formation of MCS of variable intermembrane distance. The tethering part of OSBP contains a central, dimeric, and helical T-shape region. We propose that the molecular flexibility of VAP-A enables the recruitment of partners of different sizes within MCS of adjustable thickness, whereas the T geometry of the OSBP dimer facilitates the movement of the two lipid-transfer domains between membranes.

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John F Nagle, Evan A Evans, Patricia Bassereau, Tobias Baumgart, Stephanie Tristram-Nagle, Rumiana Dimova (2021 May 6)

A needless but interesting controversy.

Proceedings of the National Academy of Sciences of the United States of America : DOI : e2025011118 En savoir plus
Résumé

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Maryam Alqabandi, Nicola de Franceschi, Sourav Maity, Nolwenn Miguet, Marta Bally, Wouter H Roos, Winfried Weissenhorn, Patricia Bassereau, Stéphanie Mangenot (2021 Apr 9)

The ESCRT-III isoforms CHMP2A and CHMP2B display different effects on membranes upon polymerization.

BMC biology : 66 : DOI : 10.1186/s12915-021-00983-9 En savoir plus
Résumé

ESCRT-III proteins are involved in many membrane remodeling processes including multivesicular body biogenesis as first discovered in yeast. In humans, ESCRT-III CHMP2 exists as two isoforms, CHMP2A and CHMP2B, but their physical characteristics have not been compared yet.

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Tsai Feng-Ching, Simunovic Mijo, Sorre Benoit , Bertin Aurélie, Manzi John, Callan-Jones Andrew, Bassereau Patricia (2021 Apr 6)

Comparing physical mechanisms for membrane curvature-driven sorting of BAR-domain proteins

Soft Matter : DOI : 10.1039/D0SM01573C En savoir plus
Résumé

Protein enrichment at specific membrane locations in cells is crucial for many cellular functions. It is well-recognized that the ability of some proteins to sense membrane curvature contributes partly to their enrichment in highly curved cellular membranes. In the past, different theoretical models have been developed to reveal the physical mechanisms underlying curvature-driven protein sorting. This review aims to provide a detailed discussion of the two continuous models that are based on the Helfrich elasticity energy, (1) the spontaneous curvature model and (2) the curvature mismatch model. These two models are commonly applied to describe experimental observations of protein sorting. We discuss how they can be used to explain the curvature-induced sorting data of two BAR proteins, amphiphysin and centaurin. We further discuss how membrane rigidity, and consequently the membrane curvature generated by BAR proteins, could influence protein organization on the curved membranes. Finally, we address future directions in extending these models to describe some cellular phenomena involving protein sorting.

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Année de publication : 2020

Zack Jarin, Alexander J Pak, Patricia Bassereau, Gregory A Voth (2020 Nov 28)

Lipid-Composition-Mediated Forces Can Stabilize Tubular Assemblies of I-BAR Proteins.

Biophysical journal : 46-54 : DOI : S0006-3495(20)30925-5 En savoir plus
Résumé

Collective action by inverse-Bin/Amphiphysin/Rvs (I-BAR) domains drive micron-scale membrane remodeling. The macroscopic curvature sensing and generation behavior of I-BAR domains is well characterized, and computational models have suggested various mechanisms on simplified membrane systems, but there remain missing connections between the complex environment of the cell and the models proposed thus far. Here, we show a connection between the role of protein curvature and lipid clustering in the relaxation of large membrane deformations. When we include phosphatidylinositol 4,5-bisphosphate-like lipids that preferentially interact with the charged ends of an I-BAR domain, we find clustering of phosphatidylinositol 4,5-bisphosphate-like lipids that induce a directional membrane-mediated interaction between membrane-bound I-BAR domains. Lipid clusters mediate I-BAR domain interactions and cause I-BAR domain aggregates that would not arise through membrane fluctuation-based or curvature-based interactions. Inside of membrane protrusions, lipid cluster-mediated interaction draws long side-by-side aggregates together, resulting in more cylindrical protrusions as opposed to bulbous, irregularly shaped protrusions.

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Abou-Ghali M, Kusters R, Körber S, Manzi J, Faix J, Sykes C, Plastino J (2020 Nov 6)

Capping protein is dispensable for polarized actin network growth and actin-based motility

Journal of Biological Chemistry : DOI : 10.1074/jbc.RA120.015009 En savoir plus
Résumé

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Pernier Julien, Morchain Antoine, Caorsi Valentina, Bertin Aurélie, Bousquet Hugo, Bassereau Patricia, Coudrier Evelyne (2020 Sep 7)

Myosin 1b Flattens and Prunes Branched Actin Filaments.

Journal of Cell Science : DOI : 10.1242/jcs.247403 En savoir plus
Résumé

Abstract
Motile and morphological cellular processes require a spatially and temporally
coordinated branched actin network that is controlled by the activity of various regulatory
proteins including the Arp2/3 complex, profilin, cofilin and tropomyosin. We have previously
reported that myosin 1b regulates the density of the actin network in the growth cone. Using
in vitro F-actin gliding assays and total internal reflection fluorescence (TIRF) microscopy we
show in this report that this molecular motor flattens the Arp2/3-dependent actin branches
up to breaking them and reduces the probability to form new branches. This experiment
reveals that myosin 1b can produce force sufficient enough to break up the Arp2/3-mediated
actin junction. Together with the former in vivo studies, this work emphasizes the essential
role played by myosins in the architecture and in the dynamics of actin networks in different
cellular regions.

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Davidson PM, Battistella A, Déjardin T, Betz T, Plastino J, Cadot B, Borghi N, Sykes C (2020 Jul 3)

Nesprin-2 accumulates at the front of the nucleus during confined cell migration

EMBO Reports : DOI : 10.15252/embr.201949910 En savoir plus
Résumé

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Aurélie Bertin , Nicola de Franceschi , Eugenio de la Mora , Sourav Maiti, Maryam Alqabandi, Nolwen Miguet, Aurélie di Cicco, Wouter H. Roos, Stéphanie Mangenot , Winfried Weissenhorn, Patricia Bassereau (2020 May 29)

Human ESCRT-III polymers assemble on positively curved membranes and induce helical membrane tube formation

Nature Communications : 11 : 2663 : DOI : 10.1038/s41467-020-16368-5 En savoir plus
Résumé

Endosomal sorting complexes for transport-III (ESCRT-III) assemble in vivo onto membranes with negative Gaussian curvature. How membrane shape influences ESCRT-III polymerization and how ESCRT-III shapes membranes is yet unclear. Human core ESCRT-III proteins, CHMP4B, CHMP2A, CHMP2B and CHMP3 are used to address this issue in vitro by combining membrane nanotube pulling experiments, cryo-electron tomography and AFM. We show that CHMP4B filaments preferentially bind to flat membranes or to tubes with positive mean curvature. Both CHMP2B and CHMP2A/CHMP3 assemble on positively curved membrane tubes. Combinations of CHMP4B/CHMP2B and CHMP4B/CHMP2A/CHMP3 are recruited to the neck of pulled membrane tubes and reshape vesicles into helical “corkscrewlike” membrane tubes. Sub-tomogram averaging reveals that the ESCRT-III filaments assemble parallel and locally perpendicular to the tube axis, highlighting the mechanical stresses imposed by ESCRT-III. Our results underline the versatile membrane remodeling activity of ESCRT-III that may be a general feature required for cellular membrane remodeling processes.

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Allard A, Bouzid M, Betz T, Simon C, Abou-Ghali M, Lemière J, Valentino F, Manzi J, Brochard-Wyart F, Guevorkian K, Plastino J, Lenz M, Campillo C*, Sykes C* (2020 Apr 22)

Actin modulates shape and mechanics of tubular membranes

Science Advances : DOI : 10.1126/sciadv.aaz3050 En savoir plus
Résumé

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Johnson Courtney R. , Steingesser Marc G., Khan Anum, Gladfelter Amy, Bertin Aurélie, McMurray Michael A. (2020 Jan 28)

Guanidine hydrochloride reactivates an ancient septin hetero-oligomer assembly pathway in budding yeast

eLife : eLife 2020;9:e54355 : DOI : DOI: 10.7554/eLife.54355 En savoir plus
Résumé

Septin proteins evolved from ancestral GTPases and co-assemble into hetero-oligomers and cytoskeletal filaments. In Saccharomyces cerevisiae, five septins comprise two species of hetero-octamers, Cdc11/Shs1–Cdc12–Cdc3–Cdc10–Cdc10–Cdc3–Cdc12–Cdc11/Shs1. Slow GTPase activity by Cdc12 directs the choice of incorporation of Cdc11 vs Shs1, but many septins, including Cdc3, lack GTPase activity. We serendipitously discovered that guanidine hydrochloride rescues septin function in cdc10 mutants by promoting assembly of non-native Cdc11/Shs1–Cdc12–Cdc3–Cdc3–Cdc12–Cdc11/Shs1 hexamers. We provide evidence that in S. cerevisiae Cdc3 guanidinium occupies the site of a ‘missing’ Arg side chain found in other fungal species where (i) the Cdc3 subunit is an active GTPase and (ii) Cdc10-less hexamers natively co-exist with octamers. We propose that guanidinium reactivates a latent septin assembly pathway that was suppressed during fungal evolution in order to restrict assembly to octamers. Since homodimerization by a GTPase-active human septin also creates hexamers that exclude Cdc10-like central subunits, our new mechanistic insights likely apply throughout phylogeny.

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Année de publication : 2019

Kusters R, Simon C, Lopes Dos Santos R, Caorsi V, Wu S, Joanny JF, Sens P, Sykes C. (2019 Dec 4)

Actin shells control buckling and wrinkling of biomembranes

Soft Matter : 15 : 9647-9653 : DOI : 10.1039/c9sm01902b En savoir plus
Résumé

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Julien Pernier, Remy Kusters, Hugo Bousquet, Thibaut Lagny, Antoine Morchain, Jean-François Joanny*, Patricia Bassereau*, Evelyne Coudrier* (2019 Nov 15)

Myosin 1b is an actin depolymerase.

Nature Communications : 10 : 5200 : DOI : 10.1038/s41467-019-13160-y En savoir plus
Résumé

The regulation of actin dynamics is essential for various cellular processes. Former evidence suggests a correlation between the function of non-conventional myosin motors and actin dynamics. Here we investigate the contribution of myosin 1b to actin dynamics using sliding motility assays. We observe that sliding on myosin 1b immobilized or bound to a fluid bilayer enhances actin depolymerization at the barbed end, while sliding on myosin II, although 5 times faster, has no effect. This work reveals a non-conventional myosin motor as another type of depolymerase and points to its singular interactions with the actin barbed end.

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