Identification and functional characterization of a novel R621C mutation in the synphilin-1 gene in Parkinson's disease.
Synphilin-1 is linked to the pathogenesis of Parkinson's disease (PD) based on its identification as an alpha-synuclein (PARK1) and parkin (PARK2) interacting protein. Moreover, synphilin-1 is a component of Lewy bodies (LB) in brains of sporadic PD patients. Therefore, we performed a detailed mutation analysis of the synphilin-1 gene in 328 German familial and sporadic PD patients. In two apparently sporadic PD patients we deciphered a novel C to T transition in position 1861 of the coding sequence leading to an amino acid substitution from arginine to cysteine in position 621 (R621C). This mutation was absent in a total of 702 chromosomes of healthy German controls. To define a possible role of mutant synphilin-1 in the pathogenesis of PD we performed functional analyses in SH-SY5Y cells. We found synphilin-1 capable of producing cytoplasmic inclusions in transfected cells. Moreover we observed a significantly reduced number of inclusions in cells expressing C621 synphilin-1 compared with cells expressing wild-type (wt) synphilin-1, when subjected to proteasomal inhibition. C621 synphilin-1 transfected cells were more susceptible to staurosporine-induced cell death than cells expressing wt synphilin-1. Our findings argue in favour of a causative role of the R621C mutation in the synphilin-1 gene in PD and suggest that the formation of intracellular inclusions may be beneficial to cells and that a mutation in synphilin-1 that reduces this ability may sensitize neurons to cellular stress.
Marx
Frank P
FP
Department of Neurology, Laboratory of Neurodegeneration, University of Tübingen, Tübingen, Germany.
Holzmann
Carsten
C
Strauss
Karsten M
KM
Li
Lei
L
Eberhardt
Olaf
O
Gerhardt
Ellen
E
Cookson
Mark R
MR
Hernandez
Dena
D
Farrer
Matt J
MJ
Kachergus
Jennifer
J
Engelender
Simone
S
Ross
Christopher A
CA
Berger
Klaus
K
Schöls
Ludger
L
Schulz
Jörg B
JB
Riess
Olaf
O
Krüger
Rejko
R
D000111:Acetylcysteine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000328:Adult; D000368:Aged; D000595:Amino Acid Sequence; D002352:Carrier Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D016022:Case-Control Studies; D016923:Cell Death / Q000187:drug effects / Q000235:genetics; D002478:Cells, Cultured; D003546:Cysteine Endopeptidases; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D005260:Female; D049452:Green Fluorescent Proteins; D006801:Humans; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D008297:Male; D008875:Middle Aged; D008969:Molecular Sequence Data; D009097:Multienzyme Complexes / Q000037:antagonists & inhibitors; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000187:drug effects / Q000235:genetics* / Q000378:metabolism; D009474:Neurons / Q000187:drug effects / Q000473:pathology / Q000502:physiology; D010300:Parkinson Disease / Q000235:genetics*; D046988:Proteasome Endopeptidase Complex; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology; D051843:Synucleins; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism; D051844:alpha-Synuclein
D002352:Carrier Proteins; D015853:Cysteine Proteinase Inhibitors; D008164:Luminescent Proteins; D009097:Multienzyme Complexes; D009419:Nerve Tissue Proteins; D011993:Recombinant Fusion Proteins; C497604:SNCA protein, human; C118958:SNCAIP protein, human; D051843:Synucleins; D051844:alpha-Synuclein; C067713:lactacystin; D049452:Green Fluorescent Proteins; D044767:Ubiquitin-Protein Ligases; C111567:parkin protein; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D019311:Staurosporine; D000111:Acetylcysteine