Dr Janet Kumita

Talk: Designing synthetic biomolecular condensates to facilitate protein degradation

The ability of the cell to rapidly partition biomolecules into membraneless organelles, or biomolecular condensates, has been linked to a diverse range of cellular functions. To understand how the dynamics and physical attributes of these biomolecular condensates are linked with their biological roles, it is necessary to explore the design of synthetic systems that allow systematic tuning of the physicochemical properties of the condensates.

To achieve this goal, we have integrated in vitro and in silico experiments to create a consensus tetratricopeptide repeat protein (CTPR) condensate system, driven to phase-separate through well-characterised low complexity domains (LCDs) appended to the N- and C-termini of the CTPR, but capable of tuning condensate propensity and material properties through rational design of the CTPR scaffold itself1.

The ability to incorporate peptide motifs to specifically recruit different client proteins, including LC3, a key protein involved in the autophagy-lysosome degradation pathway, may allow us to define a structure-function relationship between the physicochemical properties of these biomolecular condensates and their ability to target degradation via autophagy in the complex cellular environment.

This versatile system allows us to explore the condensates at a mechanistic level, using in silico modelling, in vitro experiments, and cell-based models, giving us a “bottom-up approach” to understanding how nature uses phase separation to carry out biological processes.