PUBLICATION

Insights from Molecular Dynamics Simulations: Structural Basis for the V567D Mutation-Induced Instability of Zebrafish Alpha-Dystroglycan and Comparison with the Murine Model

Authors
Pirolli, D., Sciandra, F., Bozzi, M., Giardina, B., Brancaccio, A., De Rosa, M.C.
ID
ZDB-PUB-140801-13
Date
2014
Source
PLoS One   9: e103866 (Journal)
Registered Authors
Keywords
none
MeSH Terms
  • Amino Acid Sequence
  • Animals
  • Dystroglycans/chemistry*
  • Dystroglycans/genetics
  • HEK293 Cells
  • Humans
  • Hydrogen Bonding
  • Mice
  • Molecular Dynamics Simulation
  • Molecular Sequence Data
  • Mutation, Missense
  • Protein Stability
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • Proteolysis
  • Zebrafish
  • Zebrafish Proteins/chemistry*
  • Zebrafish Proteins/genetics
PubMed
25078606 Full text @ PLoS One
Abstract
A missense amino acid mutation of valine to aspartic acid in 567 position of alpha-dystroglycan (DG), identified in dag1-mutated zebrafish, results in a reduced transcription and a complete absence of the protein. Lacking experimental structural data for zebrafish DG domains, the detailed mechanism for the observed mutation-induced destabilization of the DG complex and membrane damage, remained unclear. With the aim to contribute to a better clarification of the structure-function relationships featuring the DG complex, three-dimensional structural models of wild-type and mutant (V567D) C-terminal domain of alpha-DG from zebrafish were constructed by a template-based modelling approach. We then ran extensive molecular dynamics (MD) simulations to reveal the structural and dynamic properties of the C-terminal domain and to evaluate the effect of the single mutation on alpha-DG stability. A comparative study has been also carried out on our previously generated model of murine alpha-DG C-terminal domain including the I591D mutation, which is topologically equivalent to the V567D mutation found in zebrafish. Trajectories from MD simulations were analyzed in detail, revealing extensive structural disorder involving multiple beta-strands in the mutated variant of the zebrafish protein whereas local effects have been detected in the murine protein. A biochemical analysis of the murine alpha-DG mutant I591D confirmed a pronounced instability of the protein. Taken together, the computational and biochemical analysis suggest that the V567D/I591D mutation, belonging to the G beta-strand, plays a key role in inducing a destabilization of the alpha-DG C-terminal Ig-like domain that could possibly affect and propagate to the entire DG complex. The structural features herein identified may be of crucial help to understand the molecular basis of primary dystroglycanopathies.
Genes / Markers
Figures
Expression
Phenotype
Mutations / Transgenics
Human Disease / Model
Sequence Targeting Reagents
Fish
Antibodies
Orthology
Engineered Foreign Genes
Mapping