Understanding Phase Separation Could Impact Treatment of Neurodegenerative Disease

Living cells are amazing little biochemical factories that conduct countless chemical reactions in a cellular soup packed with lipids, proteins, nucleic acids, and ions, keeping them all in their proper places at any given time. Cells maintain this organization even while carrying out complex tasks such as cell division, signaling, transcriptional regulation, and stress responses. One example of this is the careful management of stress granule formation, a process in which membraneless organelles transiently form to control the utilization of mRNA during stress. These granules form and disperse through reversible liquid-liquid phase transitions involving proteins and RNA in the granules. Recent research has demonstrated that RNA-binding proteins in these granules contain intrinsically disordered sequences, called prion-like low-complexity domains (PLCDs), that are critical to regulation of these reversible phase transitions. There is also mounting evidence that these transitions may be disrupted in neurodegenerative diseases, like amyotrophic lateral sclerosis (ALS), in which mutations in PLCD-containing proteins, such as hnRNPA1, have been implicated as a cause of the disease. Recent …