Résumé :
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Communication n° 256. Platelet cytoskeleton is constituted by a complex group of proteins responsible for the dramatic changes in cell shape and volume that occur during platelet activation. This process, which involves both granular secretion and adhesion, is crucial to maintain haemostasis. Utrophins and dystrophins are minor actin-binding proteins involved in muscle and non-muscle cytoskeleton reorganization. The goal of this study was to investigate the role of dystrophin and utrophins in actin dynamics of suspended and glass adhered platelets. The presence of short dystrophin products such as Dp71d, Dp71D110m, utrophin gene products as well as some dystrophin associated proteins (b-dystroglycan, a-syntrophin and dystrobrevins) were characterized by western blot assays; and their cellular distribution was established by confocal microscopy. Two dystrophin associated protein complexes (DAPC) of Dp71d/Dp71D110m and Up400/Up71 respectively, were characterized by co-localization and immunoprecipitation assays. Results showed variability in each DAPC complex in relation to actin redistribution during different stages of the adhesion process. Our observations are indicative of the participation of specific DAPC in the formation of platelet structures such as the contractile ring, filopodia, lamellipodia, stress fibres, and plasma membrane patches; involved in adhesion and aggregation processes.
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