Cellular to atomic level understanding of myotonic dystrophy
In the Berglund laboratory at the University of Oregon, we use cellular and biochemical methods to determine the mechanisms that cause myotonic dystrophy, the most common adult form of muscular dystrophy. This inherited disease is caused by an expansion of a repeat sequence in the genome: specifically, the repeat is CTG at the DNA level and CUG at the RNA level. This expanded RNA is toxic to our cells and causes the formation of foci (upper left panel, cell nucleus is blue, foci are white spots). The size of this nucleus is approximately 20 micrometers (µM, 1µM = 0.000001 meters) and the bar provides a reference size. Zooming in on the foci (central panel) we find that they are formed by proteins (colored blobs) and the CUG repeat RNA (helical shapes). The size of these foci are approximately 1µM. Further magnification of the foci reveals the atomic structure of the CUG repeats themselves and the structure they form. The CUG repeat RNA is approximately 0.002 µM across. Understanding the nature of the foci, and structure of the toxic CUG repeats allows us and other scientists to begin developing strategies to treat this disease.