Résumé
Most of dystrophin, the protein product of the Duchenne muscular dystrophy locus, is composed of spectrin-like repeats, suggesting that dystrophin is an elongated cytoskeletal molecule. We present here a detailed analysis of the repeat domain of human dystrophin and propose that it is composed of 24 rather than 26 repeat units as previously suggested. Using five new anti-dystrophin antisera and two previously described antisera to detect different dystrophin peptides after proteolytic cleavage, we show that the four hinge segments are sensitive sites for proteolysis. We present a model for a membrane-associated network of dystrophin in which the hinges play a key role by conferring flexibility to the network and thus resilience to the membrane.