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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 mtT-AnxA5 to model membranes and infrared-injured cells.(a) Comparison of the binding of native AnxA5 (blue curve) and mtT-AnxA5 (red curve) to a supported lipid bilayer made of DOPC/DOPS (7:3, w/w), by QCM-D32. The formation of a supported lipid bilayer by deposition of small unilamellar vesicles on silica-coated quartz crystals takes place before t=0 mn and is not shown here. At t=0 min, a solution of 5-μg ml−1 AnxA5 or mtT-AnxA5 in HBS-Ca, pH 7.4, was injected at 150 μl min−1. The kinetics of adsorption and the adsorbed masses at saturation are almost identical for both proteins. The small difference observed between the kinetics of binding of native AnxA5 and mT-AnxA5 is equivalent to a difference in protein concentration of <1 μg ml−1, that is, 20% of nominal protein concentration, which is the level of accuracy of standard protein concentration assays. (b, c) Simultaneous recording of Cy5-mtT-AnxA5 (b) and FM1-43 (c) fluorescence of a wt-PV cell 1.6 s after 160-mW infrared-induced membrane rupture. The red arrows indicate the area of membrane irradiation. Scale bar, 10 μm.
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f6: Binding of mtT-AnxA5 to model membranes and infrared-injured cells.(a) Comparison of the binding of native AnxA5 (blue curve) and mtT-AnxA5 (red curve) to a supported lipid bilayer made of DOPC/DOPS (7:3, w/w), by QCM-D32. The formation of a supported lipid bilayer by deposition of small unilamellar vesicles on silica-coated quartz crystals takes place before t=0 mn and is not shown here. At t=0 min, a solution of 5-μg ml−1 AnxA5 or mtT-AnxA5 in HBS-Ca, pH 7.4, was injected at 150 μl min−1. The kinetics of adsorption and the adsorbed masses at saturation are almost identical for both proteins. The small difference observed between the kinetics of binding of native AnxA5 and mT-AnxA5 is equivalent to a difference in protein concentration of <1 μg ml−1, that is, 20% of nominal protein concentration, which is the level of accuracy of standard protein concentration assays. (b, c) Simultaneous recording of Cy5-mtT-AnxA5 (b) and FM1-43 (c) fluorescence of a wt-PV cell 1.6 s after 160-mW infrared-induced membrane rupture. The red arrows indicate the area of membrane irradiation. Scale bar, 10 μm.

Mentions: Strikingly, unlike native AnxA5, mtT-AnxA5 was unable to promote membrane repair (Table 1). We considered the possibility that the difference in behaviour between mtT-AnxA5 and native AnxA5 could be due to a difference in their membrane-binding properties, and measured their binding to PS-containing membranes. Native AnxA5 and mutant mtT-AnxA5 present undistinguishable binding characteristics to model membranes (Fig. 6a). This result is in agreement with previous indication that AnxA5–AnxA5 intermolecular interactions, in other words the formation of AnxA5 2D self-assemblies, does not contribute to membrane-binding affinity44. In addition, Cy5-mtT-AnxA5 bound to damaged membrane areas of irradiated wt-PV cells, similar to native AnxA5 (Fig. 6b). We conclude therefore that AnxA5 promotes membrane repair through the formation of ordered 2D arrays at the sites of membrane rupture.


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 mtT-AnxA5 to model membranes and infrared-injured cells.(a) Comparison of the binding of native AnxA5 (blue curve) and mtT-AnxA5 (red curve) to a supported lipid bilayer made of DOPC/DOPS (7:3, w/w), by QCM-D32. The formation of a supported lipid bilayer by deposition of small unilamellar vesicles on silica-coated quartz crystals takes place before t=0 mn and is not shown here. At t=0 min, a solution of 5-μg ml−1 AnxA5 or mtT-AnxA5 in HBS-Ca, pH 7.4, was injected at 150 μl min−1. The kinetics of adsorption and the adsorbed masses at saturation are almost identical for both proteins. The small difference observed between the kinetics of binding of native AnxA5 and mT-AnxA5 is equivalent to a difference in protein concentration of <1 μg ml−1, that is, 20% of nominal protein concentration, which is the level of accuracy of standard protein concentration assays. (b, c) Simultaneous recording of Cy5-mtT-AnxA5 (b) and FM1-43 (c) fluorescence of a wt-PV cell 1.6 s after 160-mW infrared-induced membrane rupture. The red arrows indicate the area of membrane irradiation. Scale bar, 10 μm.
© Copyright Policy - open-access
Related In: Results  -  Collection

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f6: Binding of mtT-AnxA5 to model membranes and infrared-injured cells.(a) Comparison of the binding of native AnxA5 (blue curve) and mtT-AnxA5 (red curve) to a supported lipid bilayer made of DOPC/DOPS (7:3, w/w), by QCM-D32. The formation of a supported lipid bilayer by deposition of small unilamellar vesicles on silica-coated quartz crystals takes place before t=0 mn and is not shown here. At t=0 min, a solution of 5-μg ml−1 AnxA5 or mtT-AnxA5 in HBS-Ca, pH 7.4, was injected at 150 μl min−1. The kinetics of adsorption and the adsorbed masses at saturation are almost identical for both proteins. The small difference observed between the kinetics of binding of native AnxA5 and mT-AnxA5 is equivalent to a difference in protein concentration of <1 μg ml−1, that is, 20% of nominal protein concentration, which is the level of accuracy of standard protein concentration assays. (b, c) Simultaneous recording of Cy5-mtT-AnxA5 (b) and FM1-43 (c) fluorescence of a wt-PV cell 1.6 s after 160-mW infrared-induced membrane rupture. The red arrows indicate the area of membrane irradiation. Scale bar, 10 μm.
Mentions: Strikingly, unlike native AnxA5, mtT-AnxA5 was unable to promote membrane repair (Table 1). We considered the possibility that the difference in behaviour between mtT-AnxA5 and native AnxA5 could be due to a difference in their membrane-binding properties, and measured their binding to PS-containing membranes. Native AnxA5 and mutant mtT-AnxA5 present undistinguishable binding characteristics to model membranes (Fig. 6a). This result is in agreement with previous indication that AnxA5–AnxA5 intermolecular interactions, in other words the formation of AnxA5 2D self-assemblies, does not contribute to membrane-binding affinity44. In addition, Cy5-mtT-AnxA5 bound to damaged membrane areas of irradiated wt-PV cells, similar to native AnxA5 (Fig. 6b). We conclude therefore that AnxA5 promotes membrane repair through the formation of ordered 2D arrays at the sites of membrane rupture.

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