J. Cell Biol. doi:10.1083/jcb.200811035 (2009)

Certain mutations in the gene LMNA cause a rare form of muscular dystrophy, possibly through improper positioning of cell nuclei. The disease, called autosomal dominant Emery-Dreifuss muscular dystrophy (AD-EDMD), and others like it are puzzling because the mutant proteins — in this case lamins A and C — are expressed throughout the body, not just in affected tissues.

Tom Misteli of the US National Cancer Institute in Bethesda, Maryland, and his colleagues looked at muscle fibres from mouse models of the disease and compared them with those of normal mice. Muscle fibres contain hundreds of nuclei, but a handful are recruited to the point where muscle and neuron meet, the neuromuscular junction. In the diseased mice, proteins found in muscle that mediate that recruitment don't associate properly with lamin A. The nuclei get misplaced, neuromuscular junctions become malformed and gene expression in the cells is disrupted.