Download MendeleyStructural insights into functional regulation of the human CPEB3 prion by an amyloid-forming segment.
Flores, M.D., Sawaya, M.R., Boyer, D.R., Zink, S., Tovmasyan, S., Saucedo, A., Richards, L.S., Zee, C.T., Cardenas, J., Fioriti, L., Rodriguez, J.A.(2025) Structure 33: 1314-1324.e5
- PubMed: 40480223
- DOI: https://doi.org/10.1016/j.str.2025.05.007
- Primary Citation of Related Structures:
8SPA - PubMed Abstract:
The cytoplasmic polyadenylation-element-binding-protein-3 (CPEB3) is a functional prion thought to modulate protein synthesis and enable consolidation of long-term memory in neurons. We report a cryoelectron microscopy (cryo-EM) structure of amyloid fibrils grown in vitro from the first prion-like domain of human CPEB3 (hCPEB3), revealing their ordered 49-residue core, spanning L103 to F151. CPEB3 lacking that segment coalesces into abnormal puncta in cells compared to wild-type CPEB3, localizes away from dormant p-bodies and toward stress granules, and lacks the ability to influence protein synthesis in neurons. Fluorescence-guided cryo-focused ion beam (cryo-FIB) milling and cryo-electron tomography (cryo-ET) applied to neuronal cells expressing CPEB3 reveal CPEB3-GFP signal from lamellae enriched in multivesicular bodies (MVBs), cavernous multilamellar compartments, and bundled filaments, suggesting a state of induced cellular stress. Accordingly, cells expressing wild-type CPEB3 are less viable than those expressing CPEB3 without its amyloid core, suggesting human CPEB3 regulation may be required to overcome the liability associated with its self-assembly in cells.
- Department of Chemistry and Biochemistry, UCLA-DOE Institute for Genomics and Proteomics, STROBE, NSF Science and Technology Center, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA. Electronic address: mflores@mbi.ucla.edu.
Organizational Affiliation:
