Alladi Ramakrishnan Hall

Signal response studies during cell polarization and external stress

Rati Sharma

Dept. of Physics,, Harvard University

Gradient detection and cell polarization are often the first two steps in the response mechanism to extracellular gradient signals. These are usually studied using mating response of the yeast S. cerevisiae as a model system [1]. In the first part of my talk, I will present a hybrid theoretical model that uses both deterministic and probabilistic features to study the response of the reaction network to a gradient stimulus. Here, I will also discuss how bistability in gene network helps with the accuracy in response [2]. Another important aspect in understanding signal response mechanism is how the organism responds under environmental stress such as heat shock [3]. In the second part of my talk, I will discuss our study of genetic interactions under heat stress through experiments on C. elegans, a roundworm often used as a model organism in systems biology studies.


References:

[1] Moore T. I., Tanaka H., Kim H. J., Jeon N. L., Yi T. M. (2013) Yeast G-proteins mediate directional sensing and polarization behaviors in response to changes in pheromone gradient direction. Mol Biol Cell. 24, 521-534.

[2] Sharma R. and Roberts E. (2016) Gradient sensing by a bistable regulatory motif enhances signal amplification but decreases accuracy in individual cells. Phys. Biol. 13 036003.

[3] Rodriguez M.,Snoek L. B., De Bono M., and Kammenga J. E. (2013) Worms under stress: C. elegans stress response and its relevance to complex human disease and aging. Trends in Genetics, 29, 367-374.