Phosphorylation of Ser-129 is the dominant pathological modification of alpha-synuclein in familial and sporadic Lewy body disease.
A comprehensive, unbiased inventory of synuclein forms present in Lewy bodies from patients with dementia with Lewy bodies was carried out using two-dimensional immunoblot analysis, novel sandwich enzyme-linked immunosorbent assays with modification-specific synuclein antibodies, and mass spectroscopy. The predominant modification of alpha-synuclein in Lewy bodies is a single phosphorylation at Ser-129. In addition, there is a set of characteristic modifications that are present to a lesser extent, including ubiquitination at Lys residues 12, 21, and 23 and specific truncations at Asp-115, Asp-119, Asn-122, Tyr-133, and Asp-135. No other modifications are detectable by tandem mass spectrometry mapping, except for a ubiquitous N-terminal acetylation. Small amounts of Ser-129 phosphorylated and Asp-119-truncated alpha-synuclein are present in the soluble fraction of both normal and disease brains, suggesting that these Lewy body-associated forms are produced during normal metabolism of alpha-synuclein. In contrast, ubiquitination is only detected in Lewy bodies and is primarily present on phosphorylated synuclein; it therefore likely occurs after phosphorylated synuclein has deposited into Lewy bodies. This invariant pattern of specific phosphorylation, truncation, and ubiquitination is also present in the detergent-insoluble fraction of brain from patients with familial Parkinson's disease (synuclein A53T mutation) as well as multiple system atrophy, suggesting a common pathogenic pathway for both genetic and sporadic Lewy body diseases. These observations are most consistent with a model in which preferential accumulation of normally produced Ser-129 phosphorylated alpha-synuclein is the key event responsible for the formation of Lewy bodies in various Lewy body diseases.
Anderson
John P
JP
Elan Pharmaceuticals, South San Francisco, California 94080, USA.
Walker
Donald E
DE
Goldstein
Jason M
JM
de Laat
Rian
R
Banducci
Kelly
K
Caccavello
Russell J
RJ
Barbour
Robin
R
Huang
Jiping
J
Kling
Kristin
K
Lee
Michael
M
Diep
Linnea
L
Keim
Pamela S
PS
Shen
Xiaofeng
X
Chataway
Tim
T
Schlossmacher
Michael G
MG
Seubert
Peter
P
Schenk
Dale
D
Sinha
Sukanto
S
Gai
Wei Ping
WP
Chilcote
Tamie J
TJ
D000595:Amino Acid Sequence; D005260:Female; D006801:Humans; D020961:Lewy Body Disease / Q000235:genetics / Q000378:metabolism* / Q000473:pathology*; D008875:Middle Aged; D008969:Molecular Sequence Data; D010766:Phosphorylation; D012694:Serine / Q000235:genetics / Q000378:metabolism*; D051844:alpha-Synuclein / Q000737:chemistry* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*
D051844:alpha-Synuclein; D012694:Serine