George Shubeita



Our group is interested in unraveling molecular mechanisms that regulate molecular-motor-driven transport within cells. We combine biophysical, biochemical, genetic and cell biology techniques to decipher the regulatory mechanisms involved in the process. We are currently using cargo transport within Drosophila embryos as a model system. Specifically, we use endogenous lipid droplets that are hauled by motors, kinesin and dynein, along microtubules. Lipid droplets are amenable to biophysical techniques such as optical trapping, fast imaging and single particle tracking. Molecular motors generate force to haul cargos. Hence, by measuring that force we are directly probing their function. We use advanced optical traps (optical tweezers) to measure that force inside the living cells. Lipid droplets are also readily isolated for biochemical analysis and other in vitro investigations and the use of Drosophila enables us to take advantage of the advanced genetics.

We address two related topics. First, the mechanisms by which motor proteins transport cargos in concord with other motors and the multitude of other regulatory proteins. Second, the strategies the cell undertakes in using these protein complexes to achieve internal self organization which appears to be robust to severe variability.


G. T. Shubeita, S. L. Tran, J. Xu, M. Vershinin, S. Cermelli, S. L. Cotton, M. A. Welte, and S. P. Gross, “Consequences of motor copy number on the intracellular transport of Kinesin-1–driven lipid droplets” Cell, 135, 1098(2008)

S. P. Gross, M. Vershinin and G. T. Shubeita, “Cargo Transport: Two Motors are Sometimes Better than One.” Current Biology, 17, R478 (2007)

Dmitri Y. Petrov, Roop Mallik, George T. Shubeita, Michael Vershinin, Steve P. Gross and Clare C. Yu, “Studying Molecular Motor-based Cargo Transport: What is Real, and What is Noise?”, Biophysical Journal, 92(8), 2953 (2007)