The prion concept, according to which proteins alone can be infectious, represents a new paradigm in biology. Such protein-only infectious agents are believed to be responsible for transmissible spongiform encephalopathies, a group of fatal neurodegenerative disorders that include Creutzfeldt-Jakob disease in humans and bovine spongiform encephalopathy in cattle. Mammalian prions propagate by a mechanism involving the conformational conversion of a largely a-helical cellular prion protein, PrPC, to misfolded, -rich amyloid-like aggregates, PrPSc. More recently, the prion hypothesis has been extended further to include the phenomenon of protein conformation-based inheritance in yeast and other fungi. Particularly puzzling features of such conformational infectivity and inheritance are the existence of so-called prion strains linked to discrete disease phenotypes within the same host species, and their role in transmissibility barriers which frequently prevent efficient prion transmission between different species. While recent studies indicate that prion strains originate from the ability of proteins to misfold into multiple distinct conformers in forming self-propagating amyloid aggregates, molecular-level understanding of these phenomena has been hampered by the paucity of high-resolution structural data. In this project we aim to advance the understanding of fundamental aspects of protein conformation-based inheritance and infectivity by providing detailed insights into the molecular mechanisms and structural basis of amyloid propagation and transmissibility barriers for a non-infectious Y145Stop PrP variant (PrP23-144). This C-truncated PrP mutant is associated with hereditary cerebral amyloid angiopathy in humans and exhibits in vitro some of the most fundamental aspects of PrP propagation including the phenomena of prion strains and species barriers.
The specific aims focus on the determination and validation of a detailed structural model for human PrP23-144 amyloid aggregates, and elucidation of the structural differences related to the emergence of distinct PrP23-144 amyloid strains with unique transmission characteristics (i.e., seeding specificities) linked to mutations of two critical amino acid residues near the C-terminus of PrP23-144. Modern multidimensional solid-state NMR spectroscopy will be the primary experimental structural technique employed in the study. In addition, we will use hydrogen/deuterium exchange solution NMR methods, atomic force microscopy and tilted-beam transmission electron microscopy.

Public Health Relevance

Prions are infectious proteins thought to cause transmissible spongiform encephalopathies (TSEs), a group of fatal neurological conditions that include Creutzfeldt-Jakob disease in humans, 'mad cow' disease in cattle, chronic wasting disease in deer and elk, and scrapie in sheep. The phenomena of prion strains and transmission barriers, both related to the structural characteristics of prion aggregates, are two critical features underlying the propagation mechanism of prions and, indeed, other amyloid-like protein aggregates. Understanding these phenomena with atomic level detail will provide novel insights about the molecular basis of prion and amyloid disorders and is of fundamental importance for public health.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM094357-05
Application #
8843460
Study Section
Macromolecular Structure and Function B Study Section (MSFB)
Program Officer
Wehrle, Janna P
Project Start
2011-06-01
Project End
2017-05-31
Budget Start
2015-06-01
Budget End
2017-05-31
Support Year
5
Fiscal Year
2015
Total Cost
Indirect Cost
Name
Ohio State University
Department
Chemistry
Type
Schools of Arts and Sciences
DUNS #
832127323
City
Columbus
State
OH
Country
United States
Zip Code
43210
Mukhopadhyay, Dwaipayan; Gupta, Chitrak; Theint, Theint et al. (2018) Peptide bond conformation in peptides and proteins probed by dipolar coupling-chemical shift tensor correlation solid-state NMR. J Magn Reson 297:152-160
Theint, Theint; Xia, Yongjie; Nadaud, Philippe S et al. (2018) Structural Studies of Amyloid Fibrils by Paramagnetic Solid-State Nuclear Magnetic Resonance Spectroscopy. J Am Chem Soc 140:13161-13166
Aucoin, Darryl; Xia, Yongjie; Theint, Theint et al. (2018) Protein-solvent interfaces in human Y145Stop prion protein amyloid fibrils probed by paramagnetic solid-state NMR spectroscopy. J Struct Biol :
Shannon, Matthew D; Theint, Theint; Mukhopadhyay, Dwaipayan et al. (2018) Conformational Dynamics in the Core of Human Y145Stop Prion Protein Amyloid Probed by Relaxation Dispersion NMR. Chemphyschem :
Mukherjee, Sujoy; Pondaven, Simon P; Hand, Kieran et al. (2017) Effect of amino acid mutations on the conformational dynamics of amyloidogenic immunoglobulin light-chains: A combined NMR and in silico study. Sci Rep 7:10339
Theint, Theint; Nadaud, Philippe S; Aucoin, Darryl et al. (2017) Species-dependent structural polymorphism of Y145Stop prion protein amyloid revealed by solid-state NMR spectroscopy. Nat Commun 8:753
Theint, Theint; Nadaud, Philippe S; Surewicz, Krystyna et al. (2017) 13C and 15N chemical shift assignments of mammalian Y145Stop prion protein amyloid fibrils. Biomol NMR Assign 11:75-80
Jaroniec, Christopher P (2015) Structural studies of proteins by paramagnetic solid-state NMR spectroscopy. J Magn Reson 253:50-9
Sengupta, Ishita; Gao, Min; Arachchige, Rajith J et al. (2015) Protein structural studies by paramagnetic solid-state NMR spectroscopy aided by a compact cyclen-type Cu(II) binding tag. J Biomol NMR 61:1-6
Gao, Min; Nadaud, Philippe S; Bernier, Morgan W et al. (2013) Histone H3 and H4 N-terminal tails in nucleosome arrays at cellular concentrations probed by magic angle spinning NMR spectroscopy. J Am Chem Soc 135:15278-81

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