Premium
Effect of Hypertrophic Cardiomyopathy‐Associated R282W Mutation of MYBPC3 on M‐domain Phosphorylation in vitro
Author(s) -
Giuffre Allison Mary,
Lynch Thomas L.,
Sadagopan Nandhini,
Sadayappan Sakthivel
Publication year - 2016
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.30.1_supplement.1012.3
Subject(s) - phosphorylation , missense mutation , mutation , hypertrophic cardiomyopathy , microbiology and biotechnology , biology , myofilament , gene , myocyte , biochemistry
Hypertrophic cardiomyopathy (HCM) is a disease of the myocardium characterized by left ventricular hypertrophy and contractile dysfunction. HCM is the most common inherited cardiac disease and is caused by mutations in sarcomeric proteins. Importantly, mutations in MYBPC3 , the gene encoding cardiac myosin binding protein‐C (cMyBP‐C), account for 40% of all HCM cases. A missense mutation causing the amino acid substitution R282W within the M‐domain of cMyBP‐C has been previously discovered in HCM patients. This mutation directly alters the protein kinase A (PKA) recognition motif for phosphorylation of the human cMyBP‐C Ser‐284. Indeed, previous studies show that phosphorylation at the homologous murine Ser‐282 residue is a prerequisite for subsequent phosphorylation of the murine Ser‐273 and Ser‐302 residues. Given the importance of cMyBP‐C phosphorylation of these residues in regulating myofilament cross‐bridge kinetics and contraction, the R282W mutation may alter cMyBP‐C phosphorylation within the M‐domain. Therefore, we determined the effect of the R282W M‐domain mutation on cMyBP‐C phosphorylation status. We hypothesized that this mutation diminishes cMyBP‐C phosphorylation at human Ser‐284. To test the hypothesis, H9C2 cells were infected with adenovirus containing cDNA encoding full‐length human WT or R282W cMyBP‐C. After 48 hours of infection, cells were treated with or without isoproterenol, to activate PKA. Western blot analysis of total cell lysates from H9C2 cells expressing R282W cMyBP‐C demonstrated a significant reduction in phosphorylation of Ser‐284, compared to WT cMyBP‐C. In conclusion, these data suggest that the R282W mutation decreases cMyBP‐C phosphorylation at Ser‐284, which may contribute to contractile dysfunction in HCM. Support or Funding Information This research was funded by the American Physiological Society.