Fluorescence Lifetime Imaging Microscopy of Biomolecular Condensates

• Published in: Methods in molecular biology (Clifton, N.J.) Vol. 2563; p. 135
• Main Authors: Quan, My Diem, Liao, Shih-Chu Jeff, Ferreon, Josephine C, Ferreon, Allan Chris M
• Format: Journal Article
• Language: English
• Published: United States 2023
• Subjects: Biomolecular Condensates; DNA-Binding Proteins - metabolism; Microscopy, Fluorescence; Protein Aggregates; Ribonucleoproteins - metabolism; Protein aggregation; Neurodegenerative diseases; Intrinsically disordered proteins; TDP-43; Droplet maturation; Liquid-liquid phase separation; Fluorescence lifetime imaging microscopy
• ISSN: 1940-6029
• DOI: 10.1007/978-1-0716-2663-4_6

Biomolecular condensates of ribonucleoproteins (RNPs) such as the transactivation response element (TAR) DNA-binding protein 43 (TDP-43) arise from liquid-liquid phase separation (LLPS) and play vital roles in various biological processes including the formation-dissolution of stress granules (SGs). These condensates are thought to be directly linked to neurodegenerative diseases, providing a depot of aggregation-prone proteins and serving as a cauldron of protein aggregation and fibrillation. Despite recent research efforts, biochemical processes and rearrangements within biomolecular condensates that trigger subsequent protein misfolding and aggregation remain to be elucidated. Fluorescence lifetime imaging microscopy (FLIM) provides a minimally intrusive high-sensitivity and high-resolution imaging method to monitor in-droplet spatiotemporal changes that initiate and lead to protein aggregation. In this chapter, we describe a FLIM application for characterizing chemical chaperone-assisted decoupling of TDP-43 liquid-liquid phase separation and aggregation/fibrillation, highlighting potential therapeutic strategies to combat pathological RNP-associated aggregates without compromising cellular stress responses.