title: Stimulation of vesicular monoamine transporter 2 activity by DJ-1 in SH-SY5Y cells.
abstract: Loss-of-functional mutation in the DJ-1 gene causes a subset of familial Parkinson's disease. The mechanism underlying DJ-1-related selective vulnerability in the dopaminergic pathway is, however, not known. Dopamine is synthesized by two enzymes and then packed into synaptic vesicles by vesicular monoamine transporter 2 (VMAT2). In this study, we found that knockdown of DJ-1 expression reduced the levels of mRNA and protein of VMAT2, resulting in reduced VMAT2 activity. Co-immunoprecipitation and pull-down experiments revealed that DJ-1 directly bound to VMAT2, and DJ-1 was co-localized with VMAT2 in cells. Furthermore, ectopic expression of wild-type DJ-1, but not that of L166P, M26I and C106S mutants of DJ-1, increased mRNA and protein levels of VMAT2 and VMAT2 activity. Since VMAT2 and a portion of DJ-1 are localized in the synaptic membrane, these results suggest that DJ-1, but not pathogenically mutated DJ-1, stimulates VMAT2 activity in the synapse by transactivation of the VMAT gene and by direct binding to VMAT2 and that cysteine 106 is necessary for the stimulating activity of DJ-1 toward VMAT2.
authors.affiliation: Graduate School of Agriculture, Hokkaido University, Kita-ku, Sapporo 060-8589, Japan.
authors.forename: Shizuma
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Yuki
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Kazuko
authors.initials: K
authors.lastname: Takahashi-Niki
authors.forename: Takeshi
authors.initials: T
authors.lastname: Niki
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Ariga
authors.forename: Sanae M M
authors.initials: SM
authors.lastname: Iguchi-Ariga
mesh_terms: D002460:Cell Line; D003545:Cysteine / Q000235:genetics / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006801:Humans; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D009154:Mutation; D015513:Oncogene Proteins / Q000235:genetics / Q000378:metabolism*; D010300:Parkinson Disease / Q000235:genetics / Q000378:metabolism*; D000071617:Protein Deglycase DJ-1; D034741:RNA, Small Interfering / Q000235:genetics; D013569:Synapses / Q000378:metabolism; D015533:Transcriptional Activation; D050493:Vesicular Monoamine Transport Proteins / Q000819:agonists* / Q000235:genetics* / Q000378:metabolism
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D015513:Oncogene Proteins; D034741:RNA, Small Interfering; C493452:SLC18A2 protein, human; D050493:Vesicular Monoamine Transport Proteins; C105131:PARK7 protein, human; D000071617:Protein Deglycase DJ-1; D003545:Cysteine