Functional importance of alpha-tropomyosin "off"-state actin-binding amino acid residues : a thesis /
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| Format: | Thesis Book |
| Language: | English |
| Published: |
[College Station, Tex.] :
[Texas A&M University System Health Science Center],
[2011]
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| Subjects: |
| Abstract: | ABSTRACT: Tropomyosin (TM) is a thin filament protein that is virtually expressed in all eukaryotic cells. It is an actin-adapted protein where in both muscle anD nonmuscle cells TM binds along F-actin and modulates actin filament dynamics and function. In the myocardium, TM is essential in regulating cardiac muscle performance and dynamics in association with other thin filament proteins. TM is a highly charged molecule, a key factor in its interaction with the myofilament proteins. In fact, its sequence is divided into 14 bands of predominantly negative charges that are subsequently divided into alternating [alpha]- and [beta]- bands. The seven [alpha]- bands are associated with the "off"-state binding of TM to actin and the seven [beta]- bands of TM are the "on"-state binding regions. While it has been suggested that the shifting of TM equilibrium between these states on actin plays a critcal role in actomyosin regualtion, the specific role of the predominant negative charges in the interacting zones have not been studied. We hypothesize that perturbation of the [alpha]- bands, by altering negatively charged residues in those regions will cause TM slipping at the "off"-state and lead to marked changes in cardiac muslce dynamics. To test this hypothesis we generated and characterized transgenic (TG) mouse lines overexpressing mutant [alpha]-TM bearing negative charged residue changes in the [alpha]-zones. We have successfully generated a transgenic DNA construct bearing the designed mutations in the [alpha]-zones of [alpha]-TM carboxyl region ([alpha]-TM-CTM). As a result we were able to generate and maintain stable transgenic mouse lines. Molecular analyses show the expression of the [alpha]-TM-CTM transgene at the mRNA and protein levels. Furthermore, we have generated a protein expression system that successfully yields the recombinant [alpha]-TM-CTM protein for future in vitro studies. Taken together, this work has generated and characterized a TG mouse model and expression system for structure-function studies of [alpha]-TM [alpha]-bands. |
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| Item Description: | Vita. "Major Subject: Medical Sciences." "Submitted to the Office of Research and Graduate Studies of the Texas A&M University System Health Science Center in partial fulfillment of the requirements for the degree of Master of Science August 2011." Approved as to style and content by: Mariappan Muthuchamy, David C. Zawieja, Emily Wilson, Harris J. Granger. |
| Physical Description: | vii, 32 leaves : illustrations ; 28 cm. |
| Bibliography: | Includes bibliographical references (leaves 30-32). |