Researchers at the University of Minnesota and National Institutes of Health have identified a new function for the protein missing in people with the most common and ultimately lethal form of childhood muscular dystrophy.
Patients with Duchenne muscular dystrophy lack the protein dystrophin, which causes their muscles to become weak and eventually die. Since its discovery in 1987, research has shown that dystrophin protects muscle cells by directly connecting to two of the three filament types that give cells their shape and durability. The new study demonstrates that dystrophin also directly links to the third structural filament type named microtubules. Microtubules form a highly ordered lattice in muscle, and the new study finds that microtubules become disorganized when dystrophin is missing.
"It's remarkable that scientists have been intensively studying dystrophin for more than 20 years, yet we continue to identify new features that better define its important contribution to healthy muscle." said James Ervasti, Ph.D., a professor in the Department of Biochemistry, Molecular Biology & Biophysics, who directed the investigation.
The new findings suggest that loss of microtubule organization might contribute to the devastating symptoms of Duchenne muscular dystrophy, information that will hopefully lead to the development of therapies to combat the disease. The study appears online Aug. 3, 2009 and will be published in the Aug. 10 issue of The Journal of Cell Biology.
The research was funded by the National Institute of Arthritis and Musculoskeletal and Skin Diseases.