Pathological biochemistry of alpha-synucleinopathy.
Lewy bodies (LBs) are hallmark lesions in the brains of patients with Parkinson's disease (PD) and dementia with Lewy bodies (DLB). We raised a monoclonal antibody LB509 against purified LBs from the brains of patients with DLB that strongly immunolabled LBs, and found that alpha-synuclein is one of the major components of LBs. Thus, the deposition of alpha-synuclein, an abundant presynaptic brain protein, as fibrillary aggregates in affected neurons or glial cells, was highlighted as a hallmark lesion of a subset of neurodegenerative disorders, including PD, DLB and multiple system atrophy collectively referred to as synucleinopathies. Importantly, the identification of missense mutations in and multiplication of alpha-synuclein gene in some pedigrees of familial PD has strongly implicated alpha-synuclein in the pathogenesis of PD and other synucleinopathies. We then examined the specific posttranslational modifications that characterize and underlie the aggregation of alpha-synuclein in synucleinopathy brains by mass spectrometry and using a specific antibody, and found that serine 129 of alpha-synuclein deposited in synucleinopathy lesions is selectively and extensively phosphorylated. Furthermore we generated transgenic C. elegans overexpressing alpha-synuclein in neurons, and found that overexpression of familial PD-linked mutant form of alpha-synuclein impairs functions of dopamine neurons. These findings collectively underscore the importance of deposition of alpha-synuclein as well as its phosphorylation in the pathogenesis of alpha-synucleinopathies.
Iwatsubo
Takeshi
T
Department of Neuropathology and Neuroscience, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo, Japan. iwatsubo@mol.f.u-tokyo.ac.jp
D015415:Biomarkers / Q000032:analysis; D006801:Humans; D007150:Immunohistochemistry; D016631:Lewy Bodies / Q000473:pathology*; D020961:Lewy Body Disease / Q000235:genetics / Q000473:pathology*; D010300:Parkinson Disease / Q000235:genetics / Q000473:pathology*; D011499:Protein Processing, Post-Translational; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*
D015415:Biomarkers; D051844:alpha-Synuclein