Abstract
Familial hypertrophic cardiomyopathy (HCM) is associated with mutations in sarcomeric proteins, including the myosin regulatory light chain (RLC). Here we studied the impact of three HCM mutations located in the NH2 terminus of the RLC on the molecular mechanism of β-myosin heavy chain (MHC) cross-bridge mechanics using the in vitro motility assay. To generate mutant β-myosin, native RLC was depleted from porcine cardiac MHC and reconstituted with mutant (A13T, F18L, and E22K) or wild-type (WT) human cardiac RLC. We characterized the mutant myosin force and motion generation capability in the presence of a frictional load. Compared with WT, all three mutants exhibited reductions in maximal actin filament velocity when tested under low or no frictional load. The actin-activated ATPase showed no significant difference between WT and HCM-mutant-reconstituted myosins. The decrease in velocity has been attributed to a significantly increased duty cycle, as was measured by the dependence of actin sliding velocity on myosin surface density, for all three mutant myosins. These results demonstrate a mutation-induced alteration in acto-myosin interactions that may contribute to the pathogenesis of HCM.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1471-1477 |
| Number of pages | 7 |
| Journal | Journal of applied physiology (Bethesda, Md. : 1985) |
| Volume | 117 |
| Issue number | 12 |
| DOIs | |
| State | Published - Dec 15 2014 |
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Keywords
- cardiac ventricular myosin
- hypertrophic cardiomyopathy
- in vitro motility
- myosin regulatory light chain
ASJC Scopus subject areas
- Medicine(all)
Cite this
Impact of familial hypertrophic cardiomyopathy-linked mutations in the NH2 terminus of the RLC on β-myosin cross-bridge mechanics. / Farman, Gerrie P.; Muthu, Priya; Kazmierczak, Katarzyna; Szczesna-Cordary, Danuta; Moore, Jeffrey R.
In: Journal of applied physiology (Bethesda, Md. : 1985), Vol. 117, No. 12, 15.12.2014, p. 1471-1477.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Impact of familial hypertrophic cardiomyopathy-linked mutations in the NH2 terminus of the RLC on β-myosin cross-bridge mechanics
AU - Farman, Gerrie P.
AU - Muthu, Priya
AU - Kazmierczak, Katarzyna
AU - Szczesna-Cordary, Danuta
AU - Moore, Jeffrey R.
PY - 2014/12/15
Y1 - 2014/12/15
N2 - Familial hypertrophic cardiomyopathy (HCM) is associated with mutations in sarcomeric proteins, including the myosin regulatory light chain (RLC). Here we studied the impact of three HCM mutations located in the NH2 terminus of the RLC on the molecular mechanism of β-myosin heavy chain (MHC) cross-bridge mechanics using the in vitro motility assay. To generate mutant β-myosin, native RLC was depleted from porcine cardiac MHC and reconstituted with mutant (A13T, F18L, and E22K) or wild-type (WT) human cardiac RLC. We characterized the mutant myosin force and motion generation capability in the presence of a frictional load. Compared with WT, all three mutants exhibited reductions in maximal actin filament velocity when tested under low or no frictional load. The actin-activated ATPase showed no significant difference between WT and HCM-mutant-reconstituted myosins. The decrease in velocity has been attributed to a significantly increased duty cycle, as was measured by the dependence of actin sliding velocity on myosin surface density, for all three mutant myosins. These results demonstrate a mutation-induced alteration in acto-myosin interactions that may contribute to the pathogenesis of HCM.
AB - Familial hypertrophic cardiomyopathy (HCM) is associated with mutations in sarcomeric proteins, including the myosin regulatory light chain (RLC). Here we studied the impact of three HCM mutations located in the NH2 terminus of the RLC on the molecular mechanism of β-myosin heavy chain (MHC) cross-bridge mechanics using the in vitro motility assay. To generate mutant β-myosin, native RLC was depleted from porcine cardiac MHC and reconstituted with mutant (A13T, F18L, and E22K) or wild-type (WT) human cardiac RLC. We characterized the mutant myosin force and motion generation capability in the presence of a frictional load. Compared with WT, all three mutants exhibited reductions in maximal actin filament velocity when tested under low or no frictional load. The actin-activated ATPase showed no significant difference between WT and HCM-mutant-reconstituted myosins. The decrease in velocity has been attributed to a significantly increased duty cycle, as was measured by the dependence of actin sliding velocity on myosin surface density, for all three mutant myosins. These results demonstrate a mutation-induced alteration in acto-myosin interactions that may contribute to the pathogenesis of HCM.
KW - cardiac ventricular myosin
KW - hypertrophic cardiomyopathy
KW - in vitro motility
KW - myosin regulatory light chain
UR - http://www.scopus.com/inward/record.url?scp=84979862406&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84979862406&partnerID=8YFLogxK
U2 - 10.1152/japplphysiol.00798.2014
DO - 10.1152/japplphysiol.00798.2014
M3 - Article
C2 - 25324513
AN - SCOPUS:84979862406
VL - 117
SP - 1471
EP - 1477
JO - Journal of Applied Physiology
JF - Journal of Applied Physiology
SN - 8750-7587
IS - 12
ER -