The cardiomyopathy and lens cataract mutation in αB-crystallin alters its protein structure, chaperone activity, and interaction withintermediate filaments in vitro

Der Perng, M.; Muchowski, P.J.; van den IJssel, P.; Wu, G.J.S.; Hutcheson, A.M.; Clark, J.I.; Quinlan, R.A.

Abstract

Desmin-related myopathy and cataract are both caused by the R120G mutation in αB-crystallin. Desmin-related myopathy is one of several diseases characterized by the coaggregation of intermediate filaments with αB-crystallin, and it identifies intermediate filaments as important physiological substrates for αB-crystallin. Using recombinant human αB-crystallin, the effects of the disease-causing mutation R120G upon the structure and the chaperone activities of αB-crystallin are reported. The secondary, tertiary, and quaternary structural features of αB-crystallin are all altered by the mutation as deduced by near- and far-UV circular dichroism spectroscopy, size exclusion chromatography, and chymotryptic digestion assays. The R120G αB-crystallin is also less stable than wild type αB-crystallin to heat-induced denaturation. These structural changes coincide with a significant reduction in thein vitro chaperone activity of the mutant αB-crystallin protein, as assessed by temperature-induced protein aggregation assays. The mutation also significantly altered the interaction of αB-crystallin with intermediate filaments. It abolished the ability of αB-crystallin to prevent those filament-filament interactions required to induce gel formation while increasing αB-crystallin binding to assembled intermediate filaments. These activities are closely correlated to the observed disease pathologies characterized by filament aggregation accompanied by αB-crystallin binding. These studies provide important insight into the mechanism of αB-crystallin-induced aggregation of intermediate filaments that causes disease.

Citation

Der Perng, M., Muchowski, P., van den IJssel, P., Wu, G., Hutcheson, A., Clark, J., & Quinlan, R. (1999). The cardiomyopathy and lens cataract mutation in αB-crystallin alters its protein structure, chaperone activity, and interaction withintermediate filaments in vitro. Journal of Biological Chemistry, 274(47), 33235-33243. https://doi.org/10.1074/jbc.274.47.33235

• Journal Article Type: Article
• Online Publication Date: Nov 19, 1999
• Publication Date: Nov 19, 1999
• Deposit Date: Dec 20, 2017
• Publicly Available Date: Dec 20, 2017
• Journal: Journal of Biological Chemistry
• Print ISSN: 0021-9258
• Electronic ISSN: 1083-351X
• Publisher: American Society for Biochemistry and Molecular Biology
• Peer Reviewed: Peer Reviewed
• Volume: 274
• Issue: 47
• Pages: 33235-33243
• DOI: https://doi.org/10.1074/jbc.274.47.33235
• Public URL: https://durham-repository.worktribe.com/output/1573800