BiFoldome: Homo- and Hetero-typic Interactions in Assembled Foldomes

Introduction

Self-assembly is a fundamental foundation of life, but what about co-assembly? The main goal of BiFOLDOME is to decipher co-assembly to understand self-assembly.

Background

Amyloids were assumed to be assembled by one type of protein, but our recent elucidation of the first 1:1 hetero-amyloid structure (the RIPK1-RIPK3 necrosome core) suggests that amyloids composed of two distinct proteins playing key roles in health and disease may be common.

In fact, a viral protein (M45) can displace one partner (RIPK1) to form a distinct 1:1 hetero-amyloid (M45-RIPK3). Taking a leaf from the viral playbook, this means that for a given self-assembling sequence there may be a mating sequence driving the preferential 1:1 co-assembly of the two.

Thus, understanding what drives the preferential formation of co-assembled forms over conventional self-assembled species will afford an entirely new vision on assembly processes transversal to all fields of knowledge.

Objectives

BiFOLDOME is organized around three different levels of complexity:

1. Characterization: Characterizing the formation, structure, and energetics of representative paradigms of 1:1 co-assembled amyloids using solution and solid-state NMR spectroscopies, and energy calculations, featuring novel technical innovations that we will develop. This will provide the basis for self-assembly by delivering a firm understanding of co-assembly.

2. Application: Applying the fundamental knowledge from (1) to the manipulation of self-assembled, disease-associated proteins using the powerful concept of 1:1 co-assembly.

3. Methodology Development: Going beyond the state of the art by developing a new methodology to study the assembly of biomolecular condensates. The approach, which I call optoNMR, will enable controlled, light-triggered self- and co-assembly of proteins within the NMR tube, opening new avenues to discern between alternative hypotheses for condensate formation and hardening in real-time and at high resolution, or for sensitive detection using hyperpolarization schemes.