%0 Journal Article %1 Debold2007 %A Debold, E. P. %A Schmitt, J. P. %A Patlak, J. B. %A Beck, S. E. %A Moore, J. R. %A Seidman, J. G. %A Seidman, C. %A Warshaw, D. M. %D 2007 %J Am J Physiol Heart Circ Physiol %K Animals C57BL Cardiomyopathy, Contraction Dilated/genetics/*metabolism Hypertrophic/genetics/*metabolism Mechanical Mice Molecular Motor Mutation Myocardial Myosins/*chemistry/*genetics Optical Proteins/*chemistry/*genetics Relationship Stress, Structure-Activity Tweezers Ventricular %N 1 %P H284-91 %T Hypertrophic and dilated cardiomyopathy mutations differentially affect the molecular force generation of mouse alpha-cardiac myosin in the laser trap assay %U http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17351073 %V 293 %X Point mutations in cardiac myosin, the heart's molecular motor, produce distinct clinical phenotypes: hypertrophic (HCM) and dilated (DCM) cardiomyopathy. Do mutations alter myosin's molecular mechanics in a manner that is predictive of the clinical outcome? We have directly characterized the maximal force-generating capacity (F(max)) of two HCM (R403Q, R453C) and two DCM (S532P, F764L) mutant myosins isolated from homozygous mouse models using a novel load-clamped laser trap assay. F(max) was 50% (R403Q) and 80% (R453C) greater for the HCM mutants compared with the wild type, whereas F(max) was severely depressed for one of the DCM mutants (65% S532P). Although F(max) was normal for the F764L DCM mutant, its actin-activated ATPase activity and actin filament velocity (V(actin)) in a motility assay were significantly reduced (Schmitt JP, Debold EP, Ahmad F, Armstrong A, Frederico A, Conner DA, Mende U, Lohse MJ, Warshaw D, Seidman CE, Seidman JG. Proc Natl Acad Sci USA 103: 14525-14530, 2006.). These F(max) data combined with previous V(actin) measurements suggest that HCM and DCM result from alterations to one or more of myosin's fundamental mechanical properties, with HCM-causing mutations leading to enhanced but DCM-causing mutations leading to depressed function. These mutation-specific changes in mechanical properties must initiate distinct signaling cascades that ultimately lead to the disparate phenotypic responses observed in HCM and DCM.

@article{Debold2007, abstract = {Point mutations in cardiac myosin, the heart's molecular motor, produce distinct clinical phenotypes: hypertrophic (HCM) and dilated (DCM) cardiomyopathy. Do mutations alter myosin's molecular mechanics in a manner that is predictive of the clinical outcome? We have directly characterized the maximal force-generating capacity (F(max)) of two HCM (R403Q, R453C) and two DCM (S532P, F764L) mutant myosins isolated from homozygous mouse models using a novel load-clamped laser trap assay. F(max) was 50% (R403Q) and 80% (R453C) greater for the HCM mutants compared with the wild type, whereas F(max) was severely depressed for one of the DCM mutants (65% S532P). Although F(max) was normal for the F764L DCM mutant, its actin-activated ATPase activity and actin filament velocity (V(actin)) in a motility assay were significantly reduced (Schmitt JP, Debold EP, Ahmad F, Armstrong A, Frederico A, Conner DA, Mende U, Lohse MJ, Warshaw D, Seidman CE, Seidman JG. Proc Natl Acad Sci USA 103: 14525-14530, 2006.). These F(max) data combined with previous V(actin) measurements suggest that HCM and DCM result from alterations to one or more of myosin's fundamental mechanical properties, with HCM-causing mutations leading to enhanced but DCM-causing mutations leading to depressed function. These mutation-specific changes in mechanical properties must initiate distinct signaling cascades that ultimately lead to the disparate phenotypic responses observed in HCM and DCM.}, added-at = {2010-12-14T18:12:02.000+0100}, author = {Debold, E. P. and Schmitt, J. P. and Patlak, J. B. and Beck, S. E. and Moore, J. R. and Seidman, J. G. and Seidman, C. and Warshaw, D. M.}, biburl = {https://www.bibsonomy.org/bibtex/241e551682be5b70e0907f14c7c9943f4/pharmawuerz}, endnotereftype = {Journal Article}, interhash = {4fc0f776c531ba0a6237f3645db2c9fc}, intrahash = {41e551682be5b70e0907f14c7c9943f4}, issn = {0363-6135 (Print) 0363-6135 (Linking)}, journal = {Am J Physiol Heart Circ Physiol}, keywords = {Animals C57BL Cardiomyopathy, Contraction Dilated/genetics/*metabolism Hypertrophic/genetics/*metabolism Mechanical Mice Molecular Motor Mutation Myocardial Myosins/*chemistry/*genetics Optical Proteins/*chemistry/*genetics Relationship Stress, Structure-Activity Tweezers Ventricular}, month = Jul, note = {Debold, Edward P Schmitt, J P Patlak, J B Beck, S E Moore, J R Seidman, J G Seidman, C Warshaw, D M Comparative Study Research Support, N.I.H., Extramural Research Support, Non-U.S. Gov't United States American journal of physiology. Heart and circulatory physiology Am J Physiol Heart Circ Physiol. 2007 Jul;293(1):H284-91. Epub 2007 Mar 9.}, number = 1, pages = {H284-91}, shorttitle = {Hypertrophic and dilated cardiomyopathy mutations differentially affect the molecular force generation of mouse alpha-cardiac myosin in the laser trap assay}, timestamp = {2010-12-14T18:22:13.000+0100}, title = {Hypertrophic and dilated cardiomyopathy mutations differentially affect the molecular force generation of mouse alpha-cardiac myosin in the laser trap assay}, url = {http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?cmd=Retrieve&db=PubMed&dopt=Citation&list_uids=17351073}, volume = 293, year = 2007 }