E. Fabbrizio et al., DYSTROPHIN, THE PROTEIN THAT PROMOTES MEMBRANE RESISTANCE, Biochemical and biophysical research communications, 213(1), 1995, pp. 295-301
Deficiency of dystrophin, a 427-kDa subsarcolemma membrane protein, is
responsible for Duchenne muscular dystrophy. The function of this pro
tein is not clear but its subcellular distribution suggests that it is
an important link between the cytoskeleton and the extracellular matr
ix, thus maintaining membrane integrity. The N-terminus of dystrophin
was shown to bind actin in vivo and in vitro via two major actin bindi
ng sites. The role of dystrophin/actin interactions has been investiga
ted and the results presented here demonstrate for the first time that
the N-terminal part of dystrophin is able (i) to interact with G-acti
n monomers, and (ii) to slowly promote G->F actin transformation. This
conversion was shown to be stimulated the presence of calmodulin in a
calcium dependent manner. This is evidence that dystrophin is an anch
or protein for actin involved in the control of membrane cell shape de
formation and developing a calmodulin-calcium induced F-actin network,
thus stiffening the myotube membrane cytoskeleton. (C) 1995 Academic
Press, Inc.