title: Characterization of prion-like conformational changes of the neuronal isoform of Aplysia CPEB.
abstract: The neuronal isoform of cytoplasmic polyadenylation element-binding protein (CPEB) is a regulator of local protein synthesis at synapses and is critical in maintaining learning-related synaptic plasticity in Aplysia. Previous studies indicate that the function of Aplysia CPEB can be modulated by conversion to a stable prion-like state, thus contributing to the stabilization of long-term memory on a molecular level. Here, we used biophysical methods to demonstrate that Aplysia CPEB, like other prions, undergoes a conformational switch from soluble α-helix-rich oligomer to β-sheet-rich fiber in vitro. Solid-state NMR analyses of the fibers indicated a relatively rigid N-terminal prion domain. The fiber form of Aplysia CPEB showed enhanced binding to target mRNAs as compared to the soluble form. Consequently, we propose a model for the Aplysia CPEB fibers that may have relevance for functional prions in general.
authors: Department of Neuroscience, Columbia University, New York, New York, USA.
authors: Bindu L
authors: BL
authors: Raveendra
authors: Ansgar B
authors: AB
authors: Siemer
authors: Sathyanarayanan V
authors: SV
authors: Puthanveettil
authors: Wayne A
authors: WA
authors: Hendrickson
authors: Eric R
authors: ER
authors: Kandel
authors: Ann E
authors: AE
authors: McDermott
mesh_terms: D000818:Animals; D001048:Aplysia / Q000378:metabolism*; D007700:Kinetics; D009474:Neurons / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D033362:Powder Diffraction; D011328:Prions / Q000737:chemistry*; D020033:Protein Isoforms / Q000737:chemistry / Q000378:metabolism*; D017433:Protein Structure, Secondary; D059748:Proteolysis; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000378:metabolism*
chemical_list: D011328:Prions; D020033:Protein Isoforms; D016601:RNA-Binding Proteins