The PRALINE database

Background

Although the composition and functions of many condensates organelles are unknown, they contain protein and RNA molecules that form heterogeneous and wide-spread liquid-like assemblies. These assemblies grow, collapse, and fuse in the nucleus and cytoplasm [32857852, 27503141] to serve a number of purposes including RNA storage in the germline [19461665] and shuttling through neurons [15312650]. Condensates is a broad term referring to macromolecular complexes with different physical state depending on their ability to form transient (liquid-like) or irreversible (solid-like) assemblies. Differently from amyloid aggregates [28062560], other condensates such as stress granules (SGs) are highly enriched in RNA content, which allows them to dissolve rapidly [27320918]. Yet, subtle changes in composition or concentration of SG constituents can induce formation of solid-like assemblies [29373831, 29798872, 26526393] such as those observed in Amyotrophic Lateral Sclerosis (ALS), where several single amino acid variations of FUS trigger a liquid-to-solid phase transition [26317470]. We hope that our database will serve to find connections between the different types of condensates and how disease-related variants relate to changes in their physical states. RNA structure plays an important role in the process of condensation. Indeed, highly structured RNAs attract large amounts of proteins thanks to their intrinsic ability to establish stable interactions [31324771]. RNAs often act as scaffolding elements: whereas a polypeptide of 100 amino acids can interact with one or two proteins, a chain of 100 nucleotides is able to bind to 5–20 proteins [34274326]. Poorly structured RNAs also play a role in condensation and especially in SGs [34274326], as they can base-pair with other RNAs establishing a dense network of contacts [29483269].