3/26, LSBM Friday Seminar Series #5, Shunsuke Shimobayashi, Soft matter physics

Presenter: Shunsuke Shimobayashi (Princeton University, chemical and biological engineering)
Date: March 26th (Fri), 11am-
Title: Intracellular phase transitions: from membrane-less protein-RNA condensates to membrane-bound lipid droplets

 

We are very excited to announce we are hosting a research seminar by Dr. Shunsuke Shimobayashi on intracellular phase transitions. We look forward to learning the advance in the field of liquid-liquid phase separation (LLPS) its future through discussions. Attendee will be LSBM/K2CORE members and their friends.

 

Presenter: Shunsuke Shimobayashi (Princeton University, chemical and biological engineering)
Date: March 26th (Fri), 11am-
Title: Intracellular phase transitions: from membrane-less protein-RNA condensates to membrane-bound lipid droplets

 

Abstract:
There is an emerging view that phase transitions play important roles in biological (dys)functions at the mesoscopic organelle scale in living cells. One of the remarkable examples is liquid-liquid phase separation (LLPS), which is potentially a physical principle to unify the formation of many types of biomolecular condensates, from membrane-less protein-RNA condensates (e.g. nucleoli) to membrane-bound lipid micro-droplets/domains.  After formation, biomolecular condensates can also undergo further phase transitions from liquid-like condensates to solid-like aggregates associated with diseases (e.g. ALS) [1].
First, I will discuss our recent synthetic approaches for understanding how the nucleation of membrane-less protein-RNA condensates can be regulated spatio-temporally in living cells [1]. The particular focus will be on how the experimental observables of the nucleation process (e.g. nucleation rates and supersaturation) can be explained by classical nucleation theories (CNT).
Secondly, I will also discuss recent findings on phase transitions/behaviors of membrane-bound lipid droplets. We found that intracellular lipid droplets undergo a phase transition to “pathological” liquid crystal condensates rather than solid-like aggregates often observed in living cells [3].

 

[1] A. Patel, et al., Cell 162, 1066-1077 (2015).
[2] S.F. Shimobayashi, et al., in revision.
[3] S. F. Shimobayashi and Y. Ohsaki, PNAS 116, 25440-25445 (2019).