Title: Discovering the physical chemistry underlying intracellular protein aggregation

Speaker: Dr. Arjun Narayanan, MIT, USA

Abstract: It is often impossible to decouple and characterize the many competing active and passive processes that maintain living cells far from equilibrium. I will discuss imaging and analysis assays to address this problem directly in the intracellular environment for the complex, highly regulated, multicomponent phenomenon of misfolded protein aggregation. Despite the underlying complexity, I will describe the discovery of a simple empirical free energy function of two coarse-grained variables that describes aggregation in our system. In keeping with the traditional power of coarse-grained descriptions in complex systems - Our effective thermodynamics leads to new insight into known stresses, allows us to predict and discover new biological regulatory mechanisms and by decoupling the underlying passive thermodynamics from the active biological regulatory processes, allows us to elucidate the precise non-equilibrium steady state that maintains homeostasis in the living cell. Along the way we will also define and measure directly from the intracellular environment of our Parkinsons related model system, the critical size for stable aggregate growth, the nucleation barrier and an effective surface tension of protein aggregates.