Interaction with synphilin-1 promotes inclusion formation of alpha-synuclein: mechanistic insights and pathological implication.
alpha-Synuclein (alpha-Syn) is the major component of Lewy bodies (LBs) deposited in the brains of patients with Parkinson's disease. Synphilin-1 (Sph1) is a novel alpha-Syn-interacting protein also present in the LBs. However, the roles of alpha-Syn-Sph1 interaction in LB formation and in the related pathogenesis are still unclear. We have studied the interaction between alpha-Syn and Sph1 by biochemical and structural approaches and found that the central coiled-coil domain of Sph1 specifically interacts with the N-terminal stretch of alpha-Syn. When overexpressed in HEK 293T cells, Sph1 forms inclusions together with alpha-Syn, but the Sph1-positive inclusions cannot recruit the N-terminally truncated alpha-Syn. The central portion of Sph1 can also recruit alpha-Syn and induce inclusion formation through its coiled-coil domain. These observations demonstrate that the alpha-Syn-Sph1 interaction significantly promotes the formation of cytoplasmic alpha-Syn inclusions, which may have implications for LB formation in neural cells. We have also elucidated solution structure of the coiled-coil domain of Sph1 and its interaction with the N-terminal peptide of alpha-Syn. The specific interaction between alpha-Syn and Sph1 provides mechanistic insights into the inclusion-body formation in cells and pathological implication in Parkinson's disease.
Xie
Yuan-Yuan
YY
State Key Laboratory of Molecular Biology, Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 320 Yueyang Road, Shanghai, China.
Zhou
Chen-Jie
CJ
Zhou
Zi-Ren
ZR
Hong
Jing
J
Che
Mei-Xia
MX
Fu
Qing-Shan
QS
Song
Ai-Xin
AX
Lin
Dong-Hai
DH
Hu
Hong-Yu
HY
D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D019281:Dimerization; D006801:Humans; D002479:Inclusion Bodies / Q000378:metabolism* / Q000473:pathology; D016631:Lewy Bodies / Q000378:metabolism / Q000473:pathology; D008958:Models, Molecular; D008969:Molecular Sequence Data; D046912:Multiprotein Complexes; D009419:Nerve Tissue Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010300:Parkinson Disease / Q000209:etiology / Q000378:metabolism / Q000473:pathology; D054730:Protein Interaction Domains and Motifs; D020836:Protein Structure, Quaternary; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D055672:Static Electricity; D051844:alpha-Synuclein / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*
D002352:Carrier Proteins; D046912:Multiprotein Complexes; D009419:Nerve Tissue Proteins; D011994:Recombinant Proteins; C118958:SNCAIP protein, human; D051844:alpha-Synuclein