[Myonuclear domain settings by microtubules and MACF1]

Skeletal myofibers are syncytia made from the fusion of dozens or hundreds of mononuclear progenitor cells. Along myogenesis, the arriving nuclei from the progenitor cells have a long journey before being positioned at the periphery of a mature myofiber. Once at the periphery, nuclei are regularly spaced and each nucleus is transcriptionally responsible for its surrounding proportion of cytoplasm, known as the myonuclear domain. Disruption of these domains can be observed in various myopathies, suggesting their importance for skeletal muscle functionality. However, little is known about mechanisms regulating the myonuclear domain stability and organization. Here we take the example of MACF1, a microtubule-associated protein, as an essential actor in myonuclear domain organization, to highlight the potential role of microtubules and their associated proteome network for the stability of these domains and hence for proper myofiber functionality.