Brandon J. Biesiadecki, Ph.D.
Education:
Ph.D., Systems Physiology, Case Western Reserve University, Cleveland, OH
Research Interest
Research in my laboratory is focused on understanding the molecular mechanisms of how muscle protein post-translational modifications (phosphorylation, radical modification, degradation, ect.) alter heart function. Key to this focus is employing an integrated and multi-level experimental approach of molecular biology, biochemistry and physiology to provide a comprehensive understanding towards the development of novel treatments for heart dysfunction.
The function of the heart as an organ is determined by its ability to pump oxygen rich blood to the organs of the body. How well the heart functions (i.e. pumps blood) is largely determined by the ability of the heart cells to produce force by shortening and generate the necessary pressures required to circulate blood. Cellular shortening is mediated by an interaction of the molecular motor myosin with actin and is regulated through the signaling molecule calcium. Muscle cell contraction can be modulated by: 1) Altering the intracellular calcium concentration. 2) Altering the response of the muscle to calcium. 3) Altering the activity of the myosin motor. My laboratorie is interested in understanding the role of protein modifications to alter the muscle’s response to calcium and affect heart function. Specifically, I am interested in understanding the physiological and pathological effects of regulated or stress induced phosphorylation and radical mediated post-translational modification of the muscle proteins that regulate the interaction of myosin with actin and their effect on cardiac contractility.
Research Approach
Approaches employed in my laboratory are broad and include the following topics:
· Biochemical Identification of Protein Modifications
Techniques including Western blot with modification specific antibodies, phosphate specific staining and 2-D isoelectric focusing (IEF) are employed to identify post-translational modifications of the muscle proteins in model systems including disease and transgenic mice.
FIGURE 1
· Biochemical Function
Techniques including molecular DNA engineering, protein expression and protein purification are employed to provide proteins containing the modification of interest. Purified proteins are then employed in biochemical assays such as the Solid Phase Protein binding assay to asses the effect of the modification on protein-protein interactions or the ATPase assay to determine the effect of the modification on muscle activation.
FIGURE 2
· Physiological Function
Through the use of protein exchange into the cardiac muscle or transgenic mouse models, muscle function experiments are employed to determine how the modification affects muscle function under physiologic conditions. Experimental techniques include the measurement of force development in the isolated and skinned cardiac muscle as well as the measurement of heart pressure development in isolated ex vivo and in situ heart preparations.
FIGURE 3
Ongoing Projects
Current projects involve investigating the molecular mechanism of how disease induced (heart failure and ischemia reperfusion) post-translational modifications and genetic mutations of the proteins that regulate force development affect cardiac muscle contraction.
External Grants
NIH (NHLBI) R00 HL091056, 10/01/09 – 09/31/12, Biesiadecki (PI).
The Role of Tropomyosin Post-translational Modification in Cardiac Muscle.
Selected Publications
· Biesiadecki B.J. and Jin J.-P. Exon skipping in cardiac troponin T of turkeys with inherited dilated cardiomyopathy. J Biol Chem 2002;277(21):18459-18468.
· Biesiadecki, B.J., Elder, B.D., Yu, Z.B. and Jin, J.-P. Cardiac troponin T variants produced by aberrant splicing of multiple exons in animals with high instances of dilated cardiomyopathy. J Biol Chem 2002;277(52):50275-50285.
· Biesiadecki, B.J., Schneider, K.L., Yu, Z.-B., Chong, S.M. and Jin, J.-P. An R111C polymorphism in wild turkey cardiac Troponin I accompanying the dilated cardiomyopathy-related abnormal splicing variant of cardiac troponin T with potentially compensatory effects. J Biol Chem 2004;279(14):13825-13832.
· Zhang, Z., Biesiadecki, B.J., Jin, J.-P. Selective removal of the N-terminal variable region of cardiac troponin-T in ischemia-reperfusion by myofibril-associated m-calpain cleavage. Biochemistry 2006;45(38):11681-11694.
· Engel, P.L., Kobayashi, T., Biesiadecki, B.J., Davis, J., Tikunova, S., Wu, S. and Solaro, R.J. Identification of a region of troponin I important in signaling cross-bridge-dependent activation of cardiac myofilament. J Biol Chem. 2007;282(1):183-193.
· Biesiadecki, B.J., Nosek, T.M. and Jin, J.-P. Functional effect of the NH2-terminal variable region of troponin T. Biochemistry 2007;46(5):1368-1379.
· Biesiadecki, B.J., Kobayashi, T., Walker, J.S., Solaro, R.J., de Tombe, P.P. Troponin C G159D mutation blunts myofilament desensitization induced by troponin I Ser-23/24 phosphorylation. Circ Res 2007;100(10):1486-1493.
· Tachampa, K., Kobayashi, T., Wang, H., Martin, A.F., Biesiadecki, B.J., Solaro, R.J., de Tombe, P.P. Increased cross-bridge cycling kinetics after exchange of C-terminal truncated troponin-I in skinned rat cardiac muscle. J Biol Chem 2008;283(22):15114-15121.
· Feng, H.-A., Biesiadecki, B.J., Yu, Z.-B., Hossain, M.M., Jin, J.-P. Restricted deletion of the N-terminal region of cardiac troponin T elongates ventricular ejection time as a functional compensation in ischemia-reperfusion and pressure overload. J Biol Chem 2008;586(14):3537-3550.
· Dias, F.A.L., Urboniene, D., Yuzhakova, M.A., Biesiadecki, B.J., Pena, J.R., Goldspink, P.H., Geenen, D.L., Wolska, B.M. Ablation of iNOS delays cardiac contractile dysfunction in chronic hypertension. Frontiers in Bioscience 2010; E2:312-324.
|
