The long-term objective of this project is to elucidate the mechanisms for 1) transduction of energy during contraction of skeletal muscle, 2) the regulation of skeletal muscle contraction by calcium ions. Since these two processes are fundamental to the functioning of normal muscle tissue, this work may provide insight into the nature of pathological muscle conditions. This objective will be achieved by determining the spatial relationships among the four major contractile proteins: myosin, actin, tropomyosin and troponin. Furthermore, how these spatial relationships change with the functional state of muscle (relaxed, activated, or in rigor) will be examined. Information so derived will be used to reconstruct the molecular events that occur during muscle contraction and its regulation. Principally, two techniques will be used to determine spatial relationships: excitation energy transfer, and photochemical crosslinking. The distances between sites in tropomyosin and in the three subunits of troponin will be determined by excitation energy transfer measurements. Simultaneously, amino acid residues at the interfaces between the proteins will be identified using photocrosslinking and peptide analysis techniques. Information derived from these studies will be used to construct a three-dimensional model for the troponin.tropomyosin complex. In a similar fashion, distances between sites in tropomyosin, actin and myosin will be determined, and the interaction interfaces between these proteins identified. This will yield information on the location of tropomyosin in the myosin.actin.tropomyosin complex, and the contact region between myosin and actin.

Agency
National Institute of Health (NIH)
Institute
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Type
Research Project (R01)
Project #
2R01AR021673-09A1
Application #
3155201
Study Section
Biophysics and Biophysical Chemistry B Study Section (BBCB)
Project Start
1979-08-01
Project End
1991-03-31
Budget Start
1986-04-01
Budget End
1987-03-31
Support Year
9
Fiscal Year
1986
Total Cost
Indirect Cost
Name
Boston Biomedical Research Institute
Department
Type
DUNS #
058893371
City
Watertown
State
MA
Country
United States
Zip Code
02472
Luo, Yin; Leszyk, John; Li, Bing et al. (2002) Troponin-I interacts with the Met47 region of skeletal muscle actin. Implications for the mechanism of thin filament regulation by calcium. J Mol Biol 316:429-34
Luo, Yin; Li, Bing; Yang, Guang et al. (2002) Cross-linking between the regulatory regions of troponin-I and troponin-C abolishes the inhibitory function of troponin. Biochemistry 41:12891-8
Li, Z; Gergely, J; Tao, T (2001) Proximity relationships between residue 117 of rabbit skeletal troponin-I and residues in troponin-C and actin. Biophys J 81:321-33
Luo, Y; Leszyk, J; Li, B et al. (2000) Proximity relationships between residue 6 of troponin I and residues in troponin C: further evidence for extended conformation of troponin C in the troponin complex. Biochemistry 39:15306-15
Luo, Y; Wu, J L; Li, B et al. (2000) Photocrosslinking of benzophenone-labeled single cysteine troponin I mutants to other thin filament proteins. J Mol Biol 296:899-910
Moses, M A; Wiederschain, D; Wu, I et al. (1999) Troponin I is present in human cartilage and inhibits angiogenesis. Proc Natl Acad Sci U S A 96:2645-50
Tao, T; Gong, B J; Grabarek, Z et al. (1999) Conformational changes induced in troponin I by interaction with troponin T and actin/tropomyosin. Biochim Biophys Acta 1450:423-33
Luo, Y; Leszyk, J; Qian, Y et al. (1999) Residues 48 and 82 at the N-terminal hydrophobic pocket of rabbit skeletal muscle troponin-C photo-cross-link to Met121 of troponin-I. Biochemistry 38:6678-88
Soman, J; Tao, T; Phillips Jr, G N (1999) Conformational variation of calcium-bound troponin C. Proteins 37:510-1
Luo, Y; Wu, J L; Gergely, J et al. (1998) Localization of Cys133 of rabbit skeletal troponin-I with respect to troponin-C by resonance energy transfer. Biophys J 74:3111-9

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