John Fricks



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Molecular Motors

Molecular motors are proteins which convert chemical energy to mechanical energy within living cells. My work has specifically focused on processive linear molecular motors which carry cargos along microtubules, especially kinesin. Since these motors are at the nanoscale and their progression requires chemical reactions, the models to describe their motion are typically stochastic.

My research has focused on creating more biologically relevant models which incorporate the interaction between chemical events and physical diffusion of the individual heads of kinesin. I have worked with William Hancock of the Bioengineering Department at Penn State and members of his lab to build these models and to link them with biological experiments. Through these efforts to connect models to experiments, we have also created statistical methods for the images that result from fluorescence microscopy experiments. This work was supported by the NSF/NIH joint initiative in mathematical biology DMS 0714939.

More recently, I have been working with an inter-university team ( William Hancock, Peter Kramer, and Scott McKinley ) to study groups of molecular motors, both kinsein and dynein, pulling a single cargo. Kinesin moves toward the plus end of a microtubule, while dynein moves towards the negative end. Knocking down one should cause increase movement in the opposite direction; however, this does not seem to happen within a cellular environment. We are focused on understanding these surprising contradictions with the hope of better understanding the regulation of motor-cargo complexes in intracellular transport. This team is currently being supported by the NIH.