Date of Award
2007
Degree Name
Biomedical Sciences
College
College of Science
Type of Degree
Ph.D.
Document Type
Dissertation
First Advisor
Gary L. Wright
Second Advisor
Elizabeth C. Bryda
Third Advisor
Todd L. Green
Fourth Advisor
William McCumbee
Fifth Advisor
Michael Moore
Abstract
The contraction mechanism of smooth muscle is not fully understood. The primary interaction that leads to the formation of tension, the myosin-actin crossbridge, has been studied extensively. However, even this aspect of the contraction has proven not to be as simple as it might seem. There are several isoforms of smooth muscle myosin and actin, and the differences in the activities of these isoforms and their interactions during the contractile process are largely unknown. The studies to be discussed are directed at the determination of the interaction of these isoforms during the contraction of rat aortic smooth muscle. Chapter II describes the association of smooth muscle myosin with two of the actin isoforms found in smooth muscle, α-actin and β-actin, using a novel method of fluorescence resonance energy transfer (FRET) to examine this association in both the A7r5 cell model and in intact tissue. We show that the contractile apparatus undergoes significant remodeling during contraction and that the interaction of myosin with α-actin and β-actin is different at the various time points of contraction. In Chapter III, we describe more detailed experiments examining the two different myosin tail isoforms, SM1 and SM2. The results of these studies confirm our findings of remodeling of the cytoskeleton and the contractile apparatus during contraction and show that α-actin and β-actin interact differently with these myosin isoforms. The results provide the first direct evidence of contractile remodeling in smooth muscle and suggest that complex changes in actin-myosin interaction may be important in the contraction of this muscle type.
Subject(s)
Smooth muscle - Contraction.
Myosin.
Actin.
Actomyosin.
Recommended Citation
Black, Jason Edward, "Association of Smooth Muscle Myosin and its Carboxyl Isoforms with Actin Isoforms in Aorta Smooth Muscle" (2007). Theses, Dissertations and Capstones. 489.
https://mds.marshall.edu/etd/489
