Physics Colloquium: From Fluids to Fibers: Liquid Phase Separation & Aggregation of Disordered ...

Thursday, May 12, 2016

3:30 PM-4:30 PM

Shana Elbaum-Garfinkle, PhD, Princeton University

From Fluids to Fibers: Liquid Phase Separation and Aggregation of Disordered Proteins

Liquid phase separation is emerging as a key process underlying intracellular organization and the assembly of non-membrane bound organelles such as P granules, nucleoli, and stress granules. These organelles exhibit liquid-like properties in vivo, however the molecular mechanisms that drive their assembly and give rise to distinct material properties are not well understood. Taking a bottom-up approach, we have identified proteins and molecular interactions that drive intracellular liquid phase separation. We combine microrheology tools with quantitative imaging techniques, to precisely measure the viscoelastic properties and molecular dynamics of protein assemblies. We find that the viscosity and dynamics within droplets are highly tunable by environmental conditions and varying components such as RNA substrates. Notably, we find that disordered proteins – a protein class long implicated in neurodegenerative protein aggregation, are important in driving liquid phase separation. This work provides mechanistic insight into how liquid phase separation gives rise to dynamic assemblies with tunable material properties that may be functionally regulated throughout development or conversely, misregulated in disease.

Contact Information

Professor Frank Ferrone
ferronfa@drexel.edu