Condensed Matter Seminar

Jay Tang
Brown University

Thursday, November 9, 2006
1:00 pm in SPL 52

Some physics of filamentous protein assembly

Abstract: Understanding how various proteins function in cells is the central task in modern biology. My laboratory of biological physics focuses on two essential proteins, actin and tubulin, which each self-assemble to form a network of filaments in a eukaryotic cell. These filaments, called F-actin and microtubules, form the skeleton of the cell. They also serve as scaffolds for enzymatic reactions, tracks for organelle transport, and the actual apparatus for cellular migration and division. This talk will illustrate several properties of F-actin and microtubules rooted in physics, including their assembly into filaments, bundles and viscoelastic networks. Detailed findings will be presented on the isotropic-nematic phase transition of F-actin and on the formation of striated patterns of growing microtubules due to a buckling instability. The fundamental physics underlining the properties of these proteins in solution contributes much to their biological functions, and in some cases, may lead to biomedical applications.