title: Proteasome-dependent degradation of cyclin D1 in 1-methyl-4-phenylpyridinium ion (MPP+)-induced cell cycle arrest.
abstract: 1-Methyl-4-phenylpyridinium ion (MPP(+)), an active metabolite of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, induces cell death and inhibition of cell proliferation in various cells. However, the mechanism whereby MPP(+) inhibits cell proliferation is still unclear. In this study, we found that MPP(+) suppressed the proliferation with accumulation in G(1) phase without inducing cell death in p53-deficient MG63 osteosarcoma cells. MPP(+) induced hypophosphorylation of retinoblastoma protein and rapidly down-regulated the protein but not mRNA levels of cyclin D1 in MG63 cells. The down-regulation of cyclin D1 protein was suppressed by a proteasome inhibitor, MG132. The cyclin D1 down-regulation by MPP(+) was also observed in p53-positive PC12, HeLa S3, and HeLa rho(0) cells, which are a subclone of HeLa S3 lacking mitochondrial DNA. Moreover, MPP(+) dephosphorylated Akt in PC12 cells, which was rescued by the pretreatment with nerve growth factor. In addition, the pretreatment with nerve growth factor or lithium chloride, a glycogen synthase kinase-3beta inhibitor, suppressed the cyclin D1 down-regulation caused by MPP(+). Our results demonstrate that MPP(+) induces cell cycle arrest independently of its mitochondrial toxicity or the p53 status of the target cells, but rather through the proteasome- and phosphatidylinositol 3-Akt-glycogen synthase kinase-3beta-dependent cyclin D1 degradation.
authors.affiliation: Department of Biological Responses, Institute for Virus Research, Kyoto University, Kyoto 606-8507, Japan.
authors.forename: Jie
authors.initials: J
authors.lastname: Bai
authors.forename: Hajime
authors.initials: H
authors.lastname: Nakamura
authors.forename: Shugo
authors.initials: S
authors.lastname: Ueda
authors.forename: Yong-Won
authors.initials: YW
authors.lastname: Kwon
authors.forename: Toru
authors.initials: T
authors.lastname: Tanaka
authors.forename: Sadayuki
authors.initials: S
authors.lastname: Ban
authors.forename: Junji
authors.initials: J
authors.lastname: Yodoi
mesh_terms: D015655:1-Methyl-4-phenylpyridinium / Q000378:metabolism*; D000818:Animals; D015152:Blotting, Northern; D015153:Blotting, Western; D002453:Cell Cycle; D002455:Cell Division; D002460:Cell Line; D045744:Cell Line, Tumor; D019938:Cyclin D1 / Q000378:metabolism*; D003546:Cysteine Endopeptidases / Q000378:metabolism*; D015853:Cysteine Proteinase Inhibitors / Q000494:pharmacology; D004272:DNA, Mitochondrial / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D015536:Down-Regulation; D005434:Flow Cytometry; D016193:G1 Phase; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006367:HeLa Cells; D006540:Herbicides; D006801:Humans; D007477:Ions; D007976:Leupeptins / Q000494:pharmacology; D008928:Mitochondria / Q000378:metabolism; D009097:Multienzyme Complexes / Q000378:metabolism*; D016716:PC12 Cells; D010766:Phosphorylation; D046988:Proteasome Endopeptidase Complex; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D012323:RNA Processing, Post-Transcriptional; D051381:Rats; D016160:Retinoblastoma Protein / Q000378:metabolism; D012694:Serine / Q000737:chemistry; D013997:Time Factors; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D015853:Cysteine Proteinase Inhibitors; D004272:DNA, Mitochondrial; D006540:Herbicides; D007477:Ions; D007976:Leupeptins; D009097:Multienzyme Complexes; D011518:Proto-Oncogene Proteins; D016160:Retinoblastoma Protein; D016159:Tumor Suppressor Protein p53; D019938:Cyclin D1; D012694:Serine; C494918:AKT1 protein, human; C494920:Akt1 protein, rat; C000605506:GSK3B protein, human; D000071679:Glycogen Synthase Kinase 3 beta; C000605508:Gsk3b protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D038362:Glycogen Synthase Kinase 3; D003546:Cysteine Endopeptidases; D046988:Proteasome Endopeptidase Complex; D015655:1-Methyl-4-phenylpyridinium; C072553:benzyloxycarbonylleucyl-leucyl-leucine aldehyde