A Two-amino Acid Mutation Encountered in Duchenne Muscular Dystrophy Decreases Stability of the Rod Domain 23 (R23) Spectrin-like Repeat of Dystrophin. - Archive ouverte HAL Access content directly
Journal Articles Journal of Biological Chemistry Year : 2009

A Two-amino Acid Mutation Encountered in Duchenne Muscular Dystrophy Decreases Stability of the Rod Domain 23 (R23) Spectrin-like Repeat of Dystrophin.

(1) , (1) , (1) , (1) , (2) , (1) , (1) , (1)
1
2

Abstract

Lack of functional dystrophin causes severe Duchenne muscular dystrophy. The subsarcolemmal location of dystrophin, as well as its association with both cytoskeleton and membrane, suggests a role in the mechanical regulation of muscular membrane stress. In particular, phenotype rescue in a Duchenne muscular dystrophy mice model has shown that some parts of the central rod domain of dystrophin, constituted by 24 spectrin-like repeats, are essential. In this study, we made use of rare missense pathogenic mutations in the dystrophin gene and analyzed the biochemical properties of the isolated repeat 23 bearing single or double mutations E2910V and N2912D found in muscle dystrophy with severity grading. No dramatic effect on secondary and tertiary structure of the repeat was found in mutants compared with wild type as revealed by circular dichroism and NMR. Thermal and chemical unfolding data from circular dichroism and tryptophan fluorescence show significant decrease of stability for the mutants, and stopped-flow spectroscopy shows decreased refolding rates. The most deleterious single mutation is the N2912D replacement, although we observe additive effects of the two mutations on repeat stability. Based on three-dimensional structures built by homology molecular modeling, we discuss the modifications of the mutation-induced repeat stability. We conclude that the main forces involved in repeat stability are electrostatic inter-helix interactions that are disrupted following mutations. This study represents the first analysis at the protein level of the consequences of missense mutations in the human dystrophin rod domain. Our results suggest that it may participate in mechanical weakening of dystrophin-deficient muscle.
Fichier principal
Vignette du fichier
legardinier_JBCsubmission_300708.pdf (1.52 Mo) Télécharger le fichier
Origin : Files produced by the author(s)
Loading...

Dates and versions

inserm-00365879 , version 1 (05-03-2009)

Identifiers

Cite

Sébastien Legardinier, Baptiste Legrand, Céline Raguénès-Nicol, Arnaud Bondon, Serge Hardy, et al.. A Two-amino Acid Mutation Encountered in Duchenne Muscular Dystrophy Decreases Stability of the Rod Domain 23 (R23) Spectrin-like Repeat of Dystrophin.. Journal of Biological Chemistry, 2009, 284 (13), pp.8822-32. ⟨10.1074/jbc.M805846200⟩. ⟨inserm-00365879⟩
81 View
203 Download

Altmetric

Share

Gmail Facebook Twitter LinkedIn More