Rubén Hervás1,2, María Del Carmen Fernández-Ramírez3, Albert Galera-Prat3, Mari Suzuki4,5, Yoshitaka Nagai4,6, Marta Bruix7, Margarita Menéndez7,8, Douglas V Laurents7, Mariano Carrión-Vázquez9. 1. Instituto Cajal, IC-CSIC, Avda. Doctor Arce 37, E-28002, Madrid, Spain. ruhm@hku.hk. 2. Present address: School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China. ruhm@hku.hk. 3. Instituto Cajal, IC-CSIC, Avda. Doctor Arce 37, E-28002, Madrid, Spain. 4. Department of Degenerative Neurological Diseases, National Institute of Neuroscience, National Center of Neurology and Psychiatry, Kodaira, Tokyo, Japan. 5. Present address: Diabetic Neuropathy Project, Department of Sensory and Motor Systems, Tokyo Metropolitan Institute of Medical Science, Setagaya, Tokyo, Japan. 6. Present address: Department of Neurology, Faculty of Medicine, Kindai University, Osaka-Sayama, Osaka, Japan. 7. Instituto de Química-Física Rocasolano, IQFR-CSIC, Serrano 119, E-28006, Madrid, Spain. 8. Centro de Investigación Biomédica en Red sobre Enfermedades Respiratorias (CIBERES), C/ Monforte de Lemos 3-5, 28029, Madrid, Spain. 9. Instituto Cajal, IC-CSIC, Avda. Doctor Arce 37, E-28002, Madrid, Spain. mcarrion@cajal.csic.es.
Abstract
BACKGROUND: Amyloids are ordered, insoluble protein aggregates, characterized by a cross-β sheet quaternary structure in which molecules in a β-strand conformation are stacked along the filament axis via intermolecular interactions. While amyloids are typically associated with pathological conditions, functional amyloids have also been identified and are present in a wide variety of organisms ranging from bacteria to humans. The cytoplasmic polyadenylation element-binding (CPEB) prion-like protein is an mRNA-binding translation regulator, whose neuronal isoforms undergo activity-dependent aggregation, a process that has emerged as a plausible biochemical substrate for memory maintenance. CPEB aggregation is driven by prion-like domains (PLD) that are divergent in sequence across species, and it remains unknown whether such divergent PLDs follow a similar aggregating assembly pathway. Here, we describe the amyloid-like features of the neuronal Aplysia CPEB (ApCPEB) PLD and compare them to those of the Drosophila ortholog, Orb2 PLD. RESULTS: Using in vitro single-molecule and bulk biophysical methods, we find transient oligomers and mature amyloid-like filaments that suggest similarities in the late stages of the assembly pathway for both ApCPEB and Orb2 PLDs. However, while prior to aggregation the Orb2 PLD monomer remains mainly as a random coil in solution, ApCPEB PLD adopts a diversity of conformations comprising α-helical structures that evolve to coiled-coil species, indicating structural differences at the beginning of their amyloid assembly pathways. CONCLUSION: Our results indicate that divergent PLDs of CPEB proteins from different species retain the ability to form a generic amyloid-like fold through different assembly mechanisms.
BACKGROUND: Amyloids are ordered, insoluble protein aggregates, characterized by a cross-β sheet quaternary structure in which molecules in a β-strand conformation are stacked along the filament axis via intermolecular interactions. While amyloids are typically associated with pathological conditions, functional amyloids have also been identified and are present in a wide variety of organisms ranging from bacteria to humans. The cytoplasmic polyadenylation element-binding (CPEB) prion-like protein is an mRNA-binding translation regulator, whose neuronal isoforms undergo activity-dependent aggregation, a process that has emerged as a plausible biochemical substrate for memory maintenance. CPEB aggregation is driven by prion-like domains (PLD) that are divergent in sequence across species, and it remains unknown whether such divergent PLDs follow a similar aggregating assembly pathway. Here, we describe the amyloid-like features of the neuronal AplysiaCPEB (ApCPEB) PLD and compare them to those of the Drosophila ortholog, Orb2 PLD. RESULTS: Using in vitro single-molecule and bulk biophysical methods, we find transient oligomers and mature amyloid-like filaments that suggest similarities in the late stages of the assembly pathway for both ApCPEB and Orb2 PLDs. However, while prior to aggregation the Orb2 PLD monomer remains mainly as a random coil in solution, ApCPEB PLD adopts a diversity of conformations comprising α-helical structures that evolve to coiled-coil species, indicating structural differences at the beginning of their amyloid assembly pathways. CONCLUSION: Our results indicate that divergent PLDs of CPEB proteins from different species retain the ability to form a generic amyloid-like fold through different assembly mechanisms.
Entities:
Keywords:
Coiled coil; Cytoplasmic polyadenylation element binding protein (CPEB); Functional amyloids; Memory persistence; Prion-like protein
Authors: Joseph S Stephan; Luana Fioriti; Nayan Lamba; Luca Colnaghi; Kevin Karl; Irina L Derkatch; Eric R Kandel Journal: Cell Rep Date: 2015-06-11 Impact factor: 9.423
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Authors: Serene W Chen; Srdja Drakulic; Emma Deas; Myriam Ouberai; Francesco A Aprile; Rocío Arranz; Samuel Ness; Cintia Roodveldt; Tim Guilliams; Erwin J De-Genst; David Klenerman; Nicholas W Wood; Tuomas P J Knowles; Carlos Alfonso; Germán Rivas; Andrey Y Abramov; José María Valpuesta; Christopher M Dobson; Nunilo Cremades Journal: Proc Natl Acad Sci U S A Date: 2015-04-08 Impact factor: 11.205