TY - JOUR
T1 - Myopathy-inducing mutation H40Y in ACTA1 hampers actin filament structure and function
AU - Chan, Chun
AU - Fan, Jun
AU - Messer, Andrew E.
AU - Marston, Steve B.
AU - Iwamoto, Hiroyuki
AU - Ochala, Julien
N1 - Publisher Copyright:
© 2016 The Authors.
PY - 2016/8/1
Y1 - 2016/8/1
N2 - In humans, more than 200 missense mutations have been identified in the ACTA1 gene. The exact molecular mechanisms by which, these particular mutations become toxic and lead to muscle weakness and myopathies remain obscure. To address this, here, we performed a molecular dynamics simulation, and we used a broad range of biophysical assays to determine how the lethal and myopathy-related H40Y amino acid substitution in actin affects the structure, stability, and function of this protein. Interestingly, our results showed that H40Y severely disrupts the DNase I-binding-loop structure and actin filaments. In addition, we observed that normal and mutant actin monomers are likely to form distinctive homopolymers, with mutant filaments being very stiff, and not supporting proper myosin binding. These phenomena underlie the toxicity of H40Y and may be considered as important triggering factors for the contractile dysfunction, muscle weakness and disease phenotype seen in patients.
AB - In humans, more than 200 missense mutations have been identified in the ACTA1 gene. The exact molecular mechanisms by which, these particular mutations become toxic and lead to muscle weakness and myopathies remain obscure. To address this, here, we performed a molecular dynamics simulation, and we used a broad range of biophysical assays to determine how the lethal and myopathy-related H40Y amino acid substitution in actin affects the structure, stability, and function of this protein. Interestingly, our results showed that H40Y severely disrupts the DNase I-binding-loop structure and actin filaments. In addition, we observed that normal and mutant actin monomers are likely to form distinctive homopolymers, with mutant filaments being very stiff, and not supporting proper myosin binding. These phenomena underlie the toxicity of H40Y and may be considered as important triggering factors for the contractile dysfunction, muscle weakness and disease phenotype seen in patients.
KW - Actin
KW - Contractile dysfunction
KW - In vitro motility assay
KW - Molecular dynamics
KW - Myopathy
KW - Small-angle X-ray scattering
UR - http://www.scopus.com/inward/record.url?scp=84971351198&partnerID=8YFLogxK
U2 - 10.1016/j.bbadis.2016.04.013
DO - 10.1016/j.bbadis.2016.04.013
M3 - Article
AN - SCOPUS:84971351198
SN - 0925-4439
VL - 1862
SP - 1453
EP - 1458
JO - Biochimica et Biophysica Acta - Molecular Basis of Disease
JF - Biochimica et Biophysica Acta - Molecular Basis of Disease
IS - 8
ER -