This project probes the arrangement of proteins and the biogenesis of membranes composing the macromolecular complexes responsible for regulated calcium release in skeletal and cardiac muscle. The basic approach is to establish molecular-structural and structural- functional correlations, under the premise that structure can be best understood by observing its changes following specific molecular perturbations, and that function cannot be fully modeled without knowledge of the underlying structure. Regarding the arrangement of proteins, the key hypotheses to be tested are: 1. calsequestrin's disposition depends on a combination of links to the SR membrane and intermolecular bonding in the presence of bivalent cations; 2. junctophilin 1 and 2 are essential for the docking of SR to surface membranes. In the absence of junctophilin the permanent association between surface and internal membrane systems may not be possible; 3. skeletal type excitation-contraction coupling, based on a molecular link between proteins of two different membrane systems, evolved at the transition between low chordates and vertebrates and it required the evolution of a new type of ryanodine receptor; 4. caveolin-3 is necessary for the development of T tubules. The experimental strategies involve perturbation of the molecular composition and developmental events by selected addition, removal and substitution of key components and perturbation of the functional state by changes in ionic composition. The structural approaches to be used center on techniques of transmission and freeze-fracture electron microscopy, correlated with immunofluorescence and confocal light microscopy. ? ?

Agency
National Institute of Health (NIH)
Institute
National Heart, Lung, and Blood Institute (NHLBI)
Type
Method to Extend Research in Time (MERIT) Award (R37)
Project #
5R37HL048093-13
Application #
7076152
Study Section
Cardiovascular and Pulmonary Research A Study Section (CVA)
Program Officer
Przywara, Dennis
Project Start
1993-07-01
Project End
2008-06-30
Budget Start
2006-07-01
Budget End
2007-06-30
Support Year
13
Fiscal Year
2006
Total Cost
$284,844
Indirect Cost
Name
University of Pennsylvania
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Lavorato, Manuela; Huang, Tai-Qin; Iyer, Venkat Ramesh et al. (2015) Dyad content is reduced in cardiac myocytes of mice with impaired calmodulin regulation of RyR2. J Muscle Res Cell Motil 36:205-14
Franzini-Armstrong, Clara (2014) Memories of Annemarie Weber. Anat Rec (Hoboken) 297:1543-7
Park, Chang Sik; Chen, Shan; Lee, Hoyong et al. (2013) Targeted ablation of the histidine-rich Ca(2+)-binding protein (HRC) gene is associated with abnormal SR Ca(2+)-cycling and severe pathology under pressure-overload stress. Basic Res Cardiol 108:344
Dayal, Anamika; Schredelseker, Johann; Franzini-Armstrong, Clara et al. (2010) Skeletal muscle excitation-contraction coupling is independent of a conserved heptad repeat motif in the C-terminus of the DHPRbeta(1a) subunit. Cell Calcium 47:500-6
Schredelseker, Johann; Dayal, Anamika; Schwerte, Thorsten et al. (2009) Proper restoration of excitation-contraction coupling in the dihydropyridine receptor beta1-null zebrafish relaxed is an exclusive function of the beta1a subunit. J Biol Chem 284:1242-51
Di Maio, Alessandro; Block, Barbara A (2008) Ultrastructure of the sarcoplasmic reticulum in cardiac myocytes from Pacific bluefin tuna. Cell Tissue Res 334:121-34
Snopko, Rose M; Ramos-Franco, Josefina; Di Maio, Alessandro et al. (2008) Ca2+ sparks and cellular distribution of ryanodine receptors in developing cardiomyocytes from rat. J Mol Cell Cardiol 44:1032-44
Di Maio, Alessandro; Ter Keurs, H E; Franzini-Armstrong, Clara (2007) T-tubule profiles in Purkinje fibres of mammalian myocardium. J Muscle Res Cell Motil 28:115-21
Chopra, Nagesh; Kannankeril, Prince J; Yang, Tao et al. (2007) Modest reductions of cardiac calsequestrin increase sarcoplasmic reticulum Ca2+ leak independent of luminal Ca2+ and trigger ventricular arrhythmias in mice. Circ Res 101:617-26
Di Maio, Alessandro; Karko, Kimberly; Snopko, Rose M et al. (2007) T-tubule formation in cardiacmyocytes: two possible mechanisms? J Muscle Res Cell Motil 28:231-41

Showing the most recent 10 out of 14 publications