1. Perturbations in desmin filament network formation in cells expressing a recombinant desmin protein harboring a 7-amino-acid deletion found in a patient with severe generalized myopathy. MCF-7 breast epithelial cells possess an IF network of keratin filaments. Since keratin and desmin do not copolymerize, they can be used to examine de novo assembly of desmin IFs. Recently, a patient with severe generalized myopathy and Z-band abnormalities was found to lack the wild-type desmin gene altogether and instead express only a mutant desmin gene encoding a 7-amino-acid residue deletion within helix 1B.272 Heterozygous carriers within the family showed no overt phenotype. To determine whether this mutation was causative for the myopathy in the patient, MCF-7 cells were transfected with mammalian expression vectors capable of expressing either (A) wild-type desmin, (B) the 7-amino-acid deletion mutant of desmin, or (C) a mixture of wild-type and mutant desmin. Forty-eight hours after transfection, cells were fixed and stained with antidesmin antibody, and labeling was visualized with a fluorescently tagged secondary antibody. Transfected cells are shown. Note that D7Des alone cannot form a proper IF network and instead produces punctate labeling at the cell periphery. In contrast, wt Des and a mixture of wt Des and D7Des assemble into a filamentous network. Bar represents 20mm. (From Munoz-Marmol et al.272 Used with permission from the Proceedings of the National Academy of Sciences.)
Source: Disorders of Intermediate Filaments and Their Associated Proteins, The Online Metabolic and Molecular Bases of Inherited Disease
Citation: Valle D, Beaudet AL, Vogelstein B, Kinzler KW, Antonarakis SE, Ballabio A, Gibson K, Mitchell G. The Online Metabolic and Molecular Bases of Inherited Disease; 2014 Available at: Accessed: October 01, 2017
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