RT Journal Article SR Electronic T1 Structure of a reversible amyloid fibril formed by the CPEB3 prion-like domain reveals a core sequence involved in translational regulation JF bioRxiv FD Cold Spring Harbor Laboratory SP 2022.12.07.519389 DO 10.1101/2022.12.07.519389 A1 Flores, Maria D. A1 Sawaya, Michael R. A1 Boyer, David R. A1 Zink, Samantha A1 Tovmasyan, Susanna A1 Saucedo, Adrian A1 Zee, Chih-Te A1 Cardenas, Jorge A1 Fioriti, Luana A1 Rodriguez, Jose A. YR 2022 UL http://biorxiv.org/content/early/2022/12/07/2022.12.07.519389.abstract AB The cytoplasmic polyadenylation element-binding protein 3 (CPEB3) is a prion-like RNA-binding polypeptide. As a functional prion, CPEB3 is thought to modulate protein synthesis at synapses and enable consolidation of long-term memory in neurons. Here, we report that the prion-like domain 1 of CPEB3 self-assembles into labile amyloid fibrils in vitro. A cryoEM structure of these fibrils reveals an ordered 48-residue core, spanning L103 to F151. CPEB3 constructs lacking this amyloidogenic segment form abnormal puncta in cells when compared to wild type CPEB3, with reduced localization in dormant p-bodies and increased localization in stress granules. Removal of the amyloid core segment in CPEB3 also abolishes its ability to regulate protein synthesis in neurons. Collectively, this evidence suggests that the newly identified amyloidogenic segment within the CPEB3 prion domain is important for its regulated aggregation in cells and suggest its involvement in regulating translational activity and potentially long-term memory formation.Competing Interest StatementJAR is an equity stake holder of MedStruc Inc.