Fig. 1: Temperature-regulated phase behavior of FUST1 promotes SG assembly and thermotolerance.
From: FUSTer than stress granules: a prion-like domain warns plants of heat
a Domain structure and thermosensitive regulation of FUST1. Left: Schematic of FUST1 (AlphaFold v.3) showing the UBA domain (blue) and PrLD (green), enriched in hydrophobic and tyrosine residues (inset). Right: Linear domain model highlighting four intrinsically disordered regions (IDRs). The temperature-dependent conformational switch of the PrLD between “locked” (inactive) and “open” (assembly-competent) states is shown. The spheres represent the hydrophobic and tyrosine residues that interact with each other, modulating the “locked” state. b Model for FUST1-mediated phase separation and its role in SG assembly. Under normal conditions, FUST1 remains diffuse and its PrLD is locked in the cytoplasm, with limited protein and RNA interaction. Upon HS, the PrLD of FUST1 transitions to an open conformation and undergoes phase separation into RNA-containing condensates. These condensates prime SG assembly, contributing to thermotolerance.
