RT Journal Article
SR Electronic
T1 α-Synuclein Phosphorylation Enhances Eosinophilic Cytoplasmic Inclusion Formation in SH-SY5Y Cells
JF The Journal of Neuroscience
JO J. Neurosci.
FD Society for Neuroscience
SP 5544
OP 5552
DO 10.1523/JNEUROSCI.0482-05.2005
VO 25
IS 23
A1 Wanli W. Smith
A1 Russell L. Margolis
A1 Xiaojie Li
A1 Juan C. Troncoso
A1 Michael K. Lee
A1 Valina L. Dawson
A1 Ted M. Dawson
A1 Takashi Iwatsubo
A1 Christopher A. Ross
YR 2005
UL http://www.jneurosci.org/content/25/23/5544.abstract
AB Parkinson's disease (PD) is a neurodegenerative disorder characterized by selective loss of dopaminergic neurons and the presence of Lewy bodies. Previous reports have shown that α-synuclein deposited in brain tissue from individuals with synucleinopathy is extensively phosphorylated at Ser-129. Here, we investigate the role of phosphorylation of α-synuclein in the formation of inclusions involving synphilin-1 and parkin using site-directed mutagenesis to change Ser-129 of α-synuclein to alanine (S129A) to abolish phosphorylation at this site. Coexpression of wild-type α-synuclein and synphilin-1 in human neuroblastoma SH-SY5Y cells yielded cytoplasmic eosinophilic inclusions with some features resembling Lewy bodies, whereas coexpression of S129A α-synuclein and synphlin-1 formed few or no inclusions. Moreover, coexpression of parkin with α-synuclein and synphilin-1 formed more ubiquitinated inclusions, but these inclusions decreased with expression of S129A α-synuclein instead of wild-type α-synuclein. Coimmunoprecipitation assays revealed a decreased interaction of S129A α-synuclein with synphilin-1 compared with wild-type α-synuclein. Expression of S129A α-synuclein instead of wild-type α-synuclein also decreased the association of synphilin-1 and parkin and subsequently reduced the parkin-mediated ubiquitination of synphilin-1 and the formation of ubiquitinated inclusions. Treatment of SH-SY5Y cells with H2O2 increased α-synuclein phosphorylation and enhanced the formation of inclusions formed by coexpression of α-synuclein, synphilin-1, and parkin, whereas treatment with the casein kinase 2 inhibitor 5,6-dichloro-1-β-d-ribofuranosylbenzimidazole had the opposite affect. These results indicate that phosphorylation of α-synuclein at S129 may be important for the formation of inclusions in PD and related α synucleinopathies.