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Annexin-A5 assembled into two-dimensional arrays promotes cell membrane repair.

Bouter A, Gounou C, Bérat R, Tan S, Gallois B, Granier T, d'Estaintot BL, Pöschl E, Brachvogel B, Brisson AR - Nat Commun (2011)

Bottom Line: Compared with wild-type mouse perivascular cells, AnxA5- cells exhibit a severe membrane repair defect.In contrast, an AnxA5 mutant that lacks the ability of forming 2D arrays is unable to promote membrane repair.We propose that AnxA5 participates in a previously unrecognized step of the membrane repair process: triggered by the local influx of Ca(2+), AnxA5 proteins bind to torn membrane edges and form a 2D array, which prevents wound expansion and promotes membrane resealing.

View Article: PubMed Central - PubMed

Affiliation: Molecular Imaging and NanoBioTechnology, IECB, UMR-5248 CBMN CNRS-University Bordeaux1-ENITAB, Talence F-33402, France.

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Binding of Cy5-AnxA5 to injured membranes.Simultaneous recording of FM1-43 (top) and Cy5-AnxA5 (bottom) fluorescence of a wt-PV cell submitted to 160-mW infrared-induced membrane rupture. Cy5-AnxA5 binds exclusively at the level of the injured membrane, colocalizing initially with FM1-43 dyes. The area of membrane irradiation is marked with a white arrow before irradiation and a red arrow after irradiation. Scale bar, 10 μm.
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f4: Binding of Cy5-AnxA5 to injured membranes.Simultaneous recording of FM1-43 (top) and Cy5-AnxA5 (bottom) fluorescence of a wt-PV cell submitted to 160-mW infrared-induced membrane rupture. Cy5-AnxA5 binds exclusively at the level of the injured membrane, colocalizing initially with FM1-43 dyes. The area of membrane irradiation is marked with a white arrow before irradiation and a red arrow after irradiation. Scale bar, 10 μm.

Mentions: Complementary experiments were performed to localize AnxA5 binding on infrared-damaged cells. Cy5-AnxA5 was found to bind exclusively to the sites of membrane injury, colocalizing with FM1-43 at initial stages after irradiation (Fig. 4). Binding of Cy5-AnxA5 occurred very rapidly after damage, in the second range, with a total absence of binding before irradiation. The fact that AnxA5 binding remains limited to damaged membrane areas at later stages indicates further that PS-exposing membranes arise from membrane injury and not from apoptosis or necrosis, in which cases AnxA5 would cover the entire cell surface (Supplementary Fig. S4).


Annexin-A5 assembled into two-dimensional arrays promotes cell membrane repair.

Bouter A, Gounou C, Bérat R, Tan S, Gallois B, Granier T, d'Estaintot BL, Pöschl E, Brachvogel B, Brisson AR - Nat Commun (2011)

Binding of Cy5-AnxA5 to injured membranes.Simultaneous recording of FM1-43 (top) and Cy5-AnxA5 (bottom) fluorescence of a wt-PV cell submitted to 160-mW infrared-induced membrane rupture. Cy5-AnxA5 binds exclusively at the level of the injured membrane, colocalizing initially with FM1-43 dyes. The area of membrane irradiation is marked with a white arrow before irradiation and a red arrow after irradiation. Scale bar, 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3104517&req=5

f4: Binding of Cy5-AnxA5 to injured membranes.Simultaneous recording of FM1-43 (top) and Cy5-AnxA5 (bottom) fluorescence of a wt-PV cell submitted to 160-mW infrared-induced membrane rupture. Cy5-AnxA5 binds exclusively at the level of the injured membrane, colocalizing initially with FM1-43 dyes. The area of membrane irradiation is marked with a white arrow before irradiation and a red arrow after irradiation. Scale bar, 10 μm.
Mentions: Complementary experiments were performed to localize AnxA5 binding on infrared-damaged cells. Cy5-AnxA5 was found to bind exclusively to the sites of membrane injury, colocalizing with FM1-43 at initial stages after irradiation (Fig. 4). Binding of Cy5-AnxA5 occurred very rapidly after damage, in the second range, with a total absence of binding before irradiation. The fact that AnxA5 binding remains limited to damaged membrane areas at later stages indicates further that PS-exposing membranes arise from membrane injury and not from apoptosis or necrosis, in which cases AnxA5 would cover the entire cell surface (Supplementary Fig. S4).

Bottom Line: Compared with wild-type mouse perivascular cells, AnxA5- cells exhibit a severe membrane repair defect.In contrast, an AnxA5 mutant that lacks the ability of forming 2D arrays is unable to promote membrane repair.We propose that AnxA5 participates in a previously unrecognized step of the membrane repair process: triggered by the local influx of Ca(2+), AnxA5 proteins bind to torn membrane edges and form a 2D array, which prevents wound expansion and promotes membrane resealing.

View Article: PubMed Central - PubMed

Affiliation: Molecular Imaging and NanoBioTechnology, IECB, UMR-5248 CBMN CNRS-University Bordeaux1-ENITAB, Talence F-33402, France.

Show MeSH
Related in: MedlinePlus