Effects of Breaking Spectrin Network via Tobacco Etch Virus Protease on Heart and Fight Muscle in Drosophila

Open Access
Author:
Kiran, Amogh
Area of Honors:
Biochemistry and Molecular Biology
Degree:
Bachelor of Science
Document Type:
Thesis
Thesis Supervisors:
  • Claire Madison Thomas, Thesis Supervisor
  • Wendy Hanna-Rose, Honors Advisor
Keywords:
  • spectrin
  • cytoskeleton
  • drosophila heart
  • TEV protease
  • spectrin cleavage
Abstract:
Spectrin is an important cytoskeletal protein that forms a network of tetramers along the intracellular side of the plasma membrane. This provides a scaffold that is vital for maintaining plasma membrane integrity and structure. In previous studies, defects in the spectrin based membrane skeleton (SBMS) were shown to cause cardiac arrhythmia and irreversible damage to cardiac tissue. The goal of my research is to look for any impairment of heart function in Drosophila caused by the cleavage of the spectrin tetramer by Tobacco Etch Virus protease (TEV). Cleavage was confirmed with western blot, and fly hearts were analyzed via semi-automatic heartbeat analysis (SOHA). Once induced, the TEV protease produces steady cleavage of -spectrin is present 0 min to 8 hours after heat shock. The amount is -spectrin cleavage is greatest at 4 hours. Multiple heat shock inductions do not show an increase in the production of cleaved -spectrin. Also, a longer heat shock length is correlated with a higher yield of cleaved -spectrin. Experimental flies with cleaved -spectrin experienced tachycardia and paralysis due to heat shock induction. Since the spectrin network is conserved in both humans and flies, the results from this project will provide a better understanding of the role spectrin plays in human muscle functionality especially during loss of oxygen in ischemic penumbra, caused by stroke, where spectrin is known to breakdown.