Systems Approaches for Study of Motor Proteins

Molecular motors proteins perform a variety of vital functions in the cell, such as mitosis, and intra-cellular transport of organelles and vesicles. While the dynamic behavior of a single motor is relatively well-understood via in-vitro experiments, there is increasing evidence that, in-vivo, multiple motors may be involved in these tasks. It is still an open question whether the presence of multiple motors leads to a coordinated behavior and to an improvement in the efficiency.The dynamics of multiple motors is also experimentally more challenging to observe because of higher resolution and bandwidth requirement. In the talk, the optical tweezer method of investigation will be developed. Systems Theory techniques can play an important role in the understanding of these biological processes. A stochastic model to describe multi-motor coupling in the transport of a common cargo, which is mathematically equivalent to the Chemical Master Equation, will be developed. The model can be used to obtain, with no use of Monte-Carlo simulations, statistics of experimentally verifiable quantities, such as step size distribution, mean cargo velocity and run-length. The model insights, apart from providing an understanding of molecular transport, also aid in shaping and driving new experiments. The biological implications resulting from this study will be elucidated. Furthermore, experimental challenges of resolution and bandwidth will be highlighted and systems theory techniques for noise reduction and estimation will be presented. In this direction a step detection method based on Dynamic Programming will be presented. Most of the work will be accompanied by experimental evidence.
Murti V. Salapaka received the B.Tech. degree in Mechanical engineering from Indian Institute of Technology, Madras, in 1991 and the M.S. and Ph.D. degrees in Mechanical engineering from the University of California at Santa Barbara, in 1993 and 1997, respectively. He was a faculty member in the Electrical and Computer Engineering Department at Iowa State University from 1997 to 2007. Currently, he is a Professor in the Electrical and Computer Engineering Department at the University of Minnesota, Minneapolis. His research interests are nanotechnology, multiple-objective robust control, and distributed and structural control. He is a 1997 National Science Foundation CAREER award recipient