Dystrophic muscles get overexcited

Loss of adhesion is a primary suspect for the underlying cause of muscular dystrophy (MD). Muscles from individuals with MD look like they are pulling themselves apart, and they are mutant for various members of the dystrophin-glycoprotein complex (DGC), which links intracellular actin to extracellular laminin. But now, Hongkyun Kim, Steven McIntire (University of California, San Francisco, CA), and colleagues suggest that loss of the DGC results in loss of an associated neurotransmitter transporter, thus leading to overexcitation of MD muscles.

Kim was screening for alcohol-resistant worms when he chanced upon the transporter mutants. Like worms mutant for the dystrophin homologue dys-1, the snf-6 mutants bent their heads excessively when they tried to move fast. Wild-type SNF-6 protein promoted uptake of the neurotransmitter acetylcholine into transfected cells, and is needed in muscle cells,...