Casein kinase II-mediated phosphorylation regulates alpha-synuclein/synphilin-1 interaction and inclusion body formation.
Alpha-synuclein is a phosphoprotein that accumulates as a major component of Lewy bodies in the brains of patients with Parkinson disease. Synphilin-1, which is also present in Lewy bodies, binds with alpha-synuclein and forms cytoplasmic inclusions in transfected cells. Yet the molecular determinants of this protein-protein interaction are unknown. Here ... we report that casein kinase II (CKII) phosphorylates synphilin-1 and that the beta subunit of this enzyme complex binds to synphilin-1. Additionally, both CKII alpha and beta subunits are present within cytoplasmic inclusions in cells that overexpress synphilin-1. Notably, the interaction between synphilin-1 and alpha-synuclein is markedly dependent on phosphorylation. Inhibition of CKII activity by 5,6-dichloro-1-beta-D-ribofuranosylbenzimidazole blocks the binding between these two proteins and significantly reduces the percentage of cells that contain eosinophilic cytoplasmic inclusions. Mutation of the major CKII phosphorylation site in alpha-synuclein (S129A) has no significant impact on the binding between alpha-synuclein and synphilin-1 or on the formation of synphilin-1/alpha-synuclein-positive inclusions. These data suggest that the CKII-mediated phosphorylation of synphilin-1 rather than that of alpha-synuclein is critical in modulating their tendency to aggregate into inclusions. These observations collectively indicate that a ubiquitous post-translational modification such as phosphorylation can regulate inclusion body formation in the context of alpha-synuclein and synphilin-1 interaction.
Mesh Terms:
Animals, Binding Sites, Blotting, Western, Carrier Proteins, Casein Kinase II, Cell Line, Cytoplasm, Dichlororibofuranosylbenzimidazole, Humans, Immunohistochemistry, Microscopy, Fluorescence, Mutation, Nerve Tissue Proteins, PC12 Cells, Phosphorylation, Protein Binding, Protein Processing, Post-Translational, Protein-Serine-Threonine Kinases, Rats, Serine, Synucleins, Transfection, alpha-Synuclein
Animals, Binding Sites, Blotting, Western, Carrier Proteins, Casein Kinase II, Cell Line, Cytoplasm, Dichlororibofuranosylbenzimidazole, Humans, Immunohistochemistry, Microscopy, Fluorescence, Mutation, Nerve Tissue Proteins, PC12 Cells, Phosphorylation, Protein Binding, Protein Processing, Post-Translational, Protein-Serine-Threonine Kinases, Rats, Serine, Synucleins, Transfection, alpha-Synuclein
J. Biol. Chem.
Date: Feb. 20, 2004
PubMed ID: 14645218
View in: Pubmed Google Scholar
Download Curated Data For This Publication
145553
Switch View:
- Interactions 4