The E22K mutation of myosin RLC that causes familial hypertrophic cardiomyopathy increases calcium sensitivity of force and ATPase in transgenic mice

Danuta Szczesna-Cordary, Georgianna Guzman, Jiaju Zhao, Olga Hernandez, Jianqin Wei, Zoraida Diaz-Perez

Research output: Contribution to journalArticle

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Abstract

Familial hypertrophic cardiomyopathy (FHC) is an autosomal dominant disease caused by mutations in all of the major sarcomeric proteins, including the ventricular myosin regulatory light-chain (RLC). The E22K-RLC mutation has been associated with a rare variant of cardiac hypertrophy defined by mid-left ventricular obstruction due to papillary muscle hypertrophy. This mutation was later found to cause ventricular and septal hypertrophy. We have generated transgenic (Tg) mouse lines of myc-WT (wild type) and myc-E22K mutant of human ventricular RLC and have examined the functional consequences of this FHC mutation in skinned cardiac-muscle preparations. In longitudinal sections of whole mouse hearts stained with hematoxylin and eosin, the E22K-mutant hearts of 13-month-old animals showed signs of inter-ventricular septal hypertrophy and enlarged papillary muscles with no filament disarray. Echo examination did not reveal evidence of cardiac hypertrophy in Tg-E22K mice compared to Tg-WT or Non-Tg hearts. Physiological studies utilizing skinned cardiac-muscle preparations showed an increase by ΔpCa50≥0.1 in Ca2+ sensitivity of myofibrillar ATPase activity and force development in Tg-E22K mice compared with Tg-WT or Non-Tg littermates. Our results suggest that E22K-linked FHC is mediated through Ca2+-dependent events. The FHC-mediated structural perturbations in RLC that affect Ca2+ binding properties of the mutated myocardium are responsible for triggering the abnormal function of the heart that in turn might initiate a hypertrophic process and lead to heart failure.

Original languageEnglish
Pages (from-to)3675-3683
Number of pages9
JournalJournal of Cell Science
Volume118
Issue number16
DOIs
StatePublished - Aug 15 2005

Fingerprint

Familial Hypertrophic Cardiomyopathy
Myosin Light Chains
Transgenic Mice
Adenosine Triphosphatases
Hypertrophy
Calcium
Myocardium
Mutation
Papillary Muscles
Cardiomegaly
Light
Ventricular Myosins
Hematoxylin
Eosine Yellowish-(YS)
Heart Failure
Proteins

Keywords

  • Hypertrophic cardiomyopathy
  • Muscles
  • Myosin regulatory light-chain
  • Physiology

ASJC Scopus subject areas

  • Cell Biology

Cite this

The E22K mutation of myosin RLC that causes familial hypertrophic cardiomyopathy increases calcium sensitivity of force and ATPase in transgenic mice. / Szczesna-Cordary, Danuta; Guzman, Georgianna; Zhao, Jiaju; Hernandez, Olga; Wei, Jianqin; Diaz-Perez, Zoraida.

In: Journal of Cell Science, Vol. 118, No. 16, 15.08.2005, p. 3675-3683.

Research output: Contribution to journalArticle

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