Résumé :
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Emerin is a type II integral membrane protein of the inner nuclear membrane and was the first nuclear membrane protein to be implicated in muscular dystrophy. Mutations in the gene STA, which encodes emerin, underlie the X-linked form of Emery Dreifuss Muscular Dystrophy (X-EDMD). X-EDMD is characterised by early contractures of tendons, slowly progressing muscle weakness and wasting and cardiac arrhythmia and cardiomyopathy which are life threatening. Two hypothesise are widely used to explain the aetiology of EDMD. The structural hypothesis proposes that proteins of the inner nuclear membrane contribute significantly to the structural integrity of the cell including the organisation of the cytoskeleton and that disruption of this organisation gives rise to fragility which in turn gives rise to cell death. The gene expression hypothesis on the other hand suggests that inner nuclear membrane proteins regulate important genetic pathways, particularly those responsible for the self-renewal and differentiation of adult stem cells. Disruption of these pathways results in a failure to regenerate adult tissues. Recent results from our group suggest that emerin does indeed contribute to the organisation of the microfilament cytoskeleton as well as contributing to the regulation of important signalling pathways. These data support the idea that the aetiology of X-EDMD which may a rise through a combination of muscle fibre degeneration resulting from fragility and a failure of skeletal muscle satellite cells to support fibre regenerate.
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