: The protein a-synuclein (aS) plays an important but poorly understood role in the pathogenesis of Parkinson's disease (PD). Mutations found in hereditary early-onset PD have been traced to the aS gene, ordered aggregates of aS are the primary component of the intracellular Lewy body deposits characteristic of PD, and mice and flies expressing human aS have provided the first transgenic animal models for PD. The normal function of aS remains unknown, but it is believed to be a synaptic vesicle-associated protein. aS undergoes a conformational change to a highly helical state upon interacting with lipid vesicles or SDS micelles, and this state is thought to represent the protein in one of possibly several normally functioning conformations. As is intrinsically unstructured when free in solution but slowly forms typical amyloid fibrils, similar to those that are found in Lewy bodies and are conjectured to play a causal role in PD. Residual structure in free aS may play an important role in mediating the intermolecular interactions that precede amyloid fibril formation, and the early-onset aS mutations may exert their pathogenic effects by modulating such residual structure. We propose to characterize, at high resolution, the structural and dynamic properties of aS in its free state using NMIR spectroscopy. We also propose to elucidate in detail the structure of SDS - and lipid vesicle-associated aS in order to gain insights into the normal structure and function of this protein. We will probe the effects of early-onset mutations (A3OP and A53T) and of newly designed aS mutations on structure and dynamics in its free and lipid-associated states. We will attempt to delineate and characterize specific sites involved in the initial oligomerization interactions that lead to aS fibril formation, and we will use mutants to test our conclusions, collaboratively, in a transgenic fly model of PD. The proposed studies are focused on improving our understanding of the molecular mechanisms underlying PD and may suggest strategies for developing new PD therapeutics. The results may have broader implications for understanding and treating other amyloid diseases, including Alzheimer's disease and the prion diseases.

Agency
National Institute of Health (NIH)
Institute
National Institute on Aging (NIA)
Type
Research Project (R01)
Project #
5R01AG019391-02
Application #
6509982
Study Section
Special Emphasis Panel (ZRG1-MDCN-2 (01))
Program Officer
Finkelstein, Judith A
Project Start
2001-04-01
Project End
2005-03-31
Budget Start
2002-04-01
Budget End
2003-03-31
Support Year
2
Fiscal Year
2002
Total Cost
$272,895
Indirect Cost
Name
Weill Medical College of Cornell University
Department
Biochemistry
Type
Schools of Medicine
DUNS #
201373169
City
New York
State
NY
Country
United States
Zip Code
10065
Ardah, Mustafa T; Paleologou, Katerina E; Lv, Guohua et al. (2015) Ginsenoside Rb1 inhibits fibrillation and toxicity of alpha-synuclein and disaggregates preformed fibrils. Neurobiol Dis 74:89-101
Eliezer, David (2012) Distance information for disordered proteins from NMR and ESR measurements using paramagnetic spin labels. Methods Mol Biol 895:127-38
Dikiy, Igor; Eliezer, David (2012) Folding and misfolding of alpha-synuclein on membranes. Biochim Biophys Acta 1818:1013-8
Hejjaoui, Mirva; Butterfield, Sara; Fauvet, Bruno et al. (2012) Elucidating the role of C-terminal post-translational modifications using protein semisynthesis strategies: ýý-synuclein phosphorylation at tyrosine 125. J Am Chem Soc 134:5196-210
Fauvet, Bruno; Fares, Mohamed-Bilal; Samuel, Filsy et al. (2012) Characterization of semisynthetic and naturally Nα-acetylated α-synuclein in vitro and in intact cells: implications for aggregation and cellular properties of α-synuclein. J Biol Chem 287:28243-62
Fauvet, Bruno; Mbefo, Martial K; Fares, Mohamed-Bilal et al. (2012) α-Synuclein in central nervous system and from erythrocytes, mammalian cells, and Escherichia coli exists predominantly as disordered monomer. J Biol Chem 287:15345-64
Harbison, Nicholas W; Bhattacharya, Shibani; Eliezer, David (2012) Assigning backbone NMR resonances for full length tau isoforms: efficient compromise between manual assignments and reduced dimensionality. PLoS One 7:e34679
Anderson, V L; Webb, W W; Eliezer, D (2012) Interplay between desolvation and secondary structure in mediating cosolvent and temperature induced alpha-synuclein aggregation. Phys Biol 9:056005
Stratton, Margaret M; McClendon, Sebastian; Eliezer, David et al. (2011) Structural characterization of two alternate conformations in a calbindin D₉k-based molecular switch. Biochemistry 50:5583-9
Paleologou, Katerina E; Oueslati, Abid; Shakked, Gideon et al. (2010) Phosphorylation at S87 is enhanced in synucleinopathies, inhibits alpha-synuclein oligomerization, and influences synuclein-membrane interactions. J Neurosci 30:3184-98

Showing the most recent 10 out of 34 publications