The ESCRT-III Isoforms CHMP2A And CHMP2B Display Different Effects On Membranes Upon Polymerization

Alqabandi, Maryam; Franceschi, Nicola De; Miguet, Nolwenn; Maity, Sourav; Bally, Marta; Roos, Wouter H.; Weissenhorn, Winfríed; Bassereau, Patricia; Mangenot, Stéphanie

doi:10.1101/756403

Cited by 7 publications

(10 citation statements)

References 70 publications

(94 reference statements)

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“…CHMP2A and CHMP3 have to be present together for binding negatively charged membranes 19,52 . We thus first studied whether CHMP2A/CHMP3 assembles inside nanotubes, using the geometry (iii) (Fig.…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2020

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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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Section: Resultsmentioning

confidence: 99%

“…In these experiments, only CHMP2A was fluorescently labeled and CHMP3 was kept unlabeled (see ref. 52 ). Proteins were reconstituted inside GUVs at low micromolar concentrations.…”

Section: Resultsmentioning

confidence: 99%

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

et al. 2020

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“…These findings also have parallels in eukaryotes. In mammalian cells, for example, the two ESCRT-III proteins CHMP2A and CHMP2B, which we previously assumed to be functional homologues, were recently found to contribute differently to membrane remodelling and to have different affinities for the membrane [31]. Moreover, in in vitro studies, different eukaryotic ESCRT-III proteins have been shown to work together to increase membrane binding of the heteropolymer [32].…”

Section: Discussionmentioning

confidence: 99%

Live cell imaging of the hyperthermophilic archaeonSulfolobus acidocaldariusidentifies complementary roles for two ESCRTIII homologues in ensuring a robust and symmetric cell division

et al. 2020

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Live-cell imaging has revolutionized our understanding of dynamic cellular processes in bacteria and eukaryotes. While similar techniques have recently been applied to the study of halophilic archaea, our ability to explore the cell biology of thermophilic archaea is limited, due to the technical challenges of imaging at high temperatures. Here, we report the construction of the Sulfoscope, a heated chamber that enables live-cell imaging on an inverted fluorescent microscope. Using this system combined with thermostable fluorescent probes, we were able to image Sulfolobus cells as they divide, revealing a tight coupling between changes in DNA compaction, segregation and cytokinesis. By imaging deletion mutants, we observe important differences in the function of the two ESCRTIII proteins recently implicated in cytokinesis. The loss of CdvB1 compromises cell division, causing occasional division failures and fusion of the two daughter cells, whereas the deletion of cdvB2 leads to a profound loss of division symmetry, generating daughter cells that vary widely in size and eventually generating ghost cells. These data indicate that DNA separation and cytokinesis are coordinated in Sulfolobus, as is the case in eukaryotes, and that two contractile ESCRTIII polymers perform distinct roles to ensure that Sulfolobus cells undergo a robust and symmetrical division. Taken together, the Sulfoscope has shown to provide a controlled high temperature environment, in which cell biology of Sulfolobus can be studied in unprecedent details. AAP, DRM, GD, RH and BB conceived the study. Microscope design and construction and commercial heating stage testing was carried out by AAP, SC, GD, DRM and RH. Design of the heating cap and heating stage was carried out by AAP, JR, CR and MR. JR and MR constructed the heating cap and heating stage. AAP and DRM established the imaging methodology and dyes used. Live-imaging and imaging analysis were performed by AAP and DRM with help from SC. Genetics and strains were performed by AAP, MVW and KNS. Immunofluorescence and Western-Blots were performed by AAP. Flow Cytometry were performed by GTR. Chamber measurements were performed

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“…CHMP2A and CHMP3 have to be present together for efficiently binding negatively charged membranes 23,61 . We thus first studied whether CHMP2A/CHMP3 assembles inside nanotubes, using the geometry of the assay (iii) (Fig.…”

Section: Chmp2a/chmp3mentioning

confidence: 99%

“…1D). In these experiments, only CHMP2A was fluorescently labeled and CHMP3 was kept unlabeled (see 61 ). Proteins were reconstituted inside GUVs at nearly physiological concentrations.…”

Section: Chmp2a/chmp3mentioning

confidence: 99%

Human ESCRT-III Polymers Assemble on Positively Curved Membranes and Induce Helical Membrane Tube Formation

Bertin

Franceschi

Mora

et al. 2019

Preprint

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Endosomal sorting complexes required for transport-III (ESCRT-III) are thought to assemble in vivo inside membrane structures with a negative Gaussian curvature. How membrane shape influences ESCRT-III polymerization and conversely how ESCRT-III polymers shape membranes is still unclear. Here, we used human core ESCRT-III proteins, CHMP4B, CHMP2A, CHMP2B and CHMP3 to address this issue in vitro by combining membrane nanotube pulling experiments, cryo-electron microscopy, cryo-electron tomography and highspeed AFM. We show that CHMP4B filaments bind preferentially to flat membranes or to membrane tubes with a positive mean curvature. Both CHMP2B and CHMP2A/CHMP3 assemble on positively curved membrane tubes, the latter winding around the tubes. Although combinations of CHMP4B/CHMP2B and CHMP4B/CHMP2A/CHMP3 are recruited to the neck of pulled membrane tubes, they also reshape large unilamellar vesicles into helical membrane tubes with a pipe surface shape. Sub-tomogram averaging reveals that the filaments assemble parallel to the tube axis with some local perpendicular connections, highlighting the particular mechanical stresses imposed by ESCRT-III to stabilize the corkscrew-like membrane architecture. Our results thus underline the versatile membrane remodeling activity of ESCRT-III that may be a general feature of ESCRT-III required for all or selected cellular membrane remodeling processes.

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The ESCRT-III Isoforms CHMP2A And CHMP2B Display Different Effects On Membranes Upon Polymerization

Cited by 7 publications

References 70 publications

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

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

Live cell imaging of the hyperthermophilic archaeonSulfolobus acidocaldariusidentifies complementary roles for two ESCRTIII homologues in ensuring a robust and symmetric cell division

Human ESCRT-III Polymers Assemble on Positively Curved Membranes and Induce Helical Membrane Tube Formation

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