title: Mutated ras induced PLD1 gene expression through increased Sp1 transcription factor.
abstract: The underlying mechanisms of oncogene-induced phospholipase D (PLD) activation have not been fully elucidated. The effect of the mutated-ras on PLD mRNA was examined using colon cancer cell lines as well as mock- and mutated ras-transfected NIH3T3 cells. Ras-mutation and activation were correlated, and cells with enhanced ras-activation showed increased PLD1 mRNA and protein. Analysis of the 5' PLD1 promoter using a representative cell line, DLD-1 and also mutated ras-NIH3T3, showed one Sp1-site as the important ras-responsible motif. Spl inhibition with mithramycin A and Spl siRNA inhibited PLD1 protein expression and its promoter activity. Sp1 but not Sp3 protein level and increased Sp1-motif binding activity were correlated with ras activation. Furthermore, overexpression of Sp1 in drosophila SL2 cells lacking Sp family proteins increased PLD1 promoter activity. EMSA and chromatin immunoprecipitation assay confirmed the importance of Sp1 protein binding to the Sp1-motif in ras-induced PLD1 mRNA expression.
authors.affiliation: Department of Medical Technology, Nagoya University Graduate School of Health Sciences, Nagoya, Japan.
authors.forename: Siqiang
authors.initials: S
authors.lastname: Gao
authors.forename: Masashi
authors.initials: M
authors.lastname: Murakami
authors.forename: Hiromi
authors.initials: H
authors.lastname: Ito
authors.forename: Ayako
authors.initials: A
authors.lastname: Furuhata
authors.forename: Kayo
authors.initials: K
authors.lastname: Yoshida
authors.forename: Yoko
authors.initials: Y
authors.lastname: Tagawa
authors.forename: Kazumi
authors.initials: K
authors.lastname: Hagiwara
authors.forename: Akira
authors.initials: A
authors.lastname: Takagi
authors.forename: Tetsuhito
authors.initials: T
authors.lastname: Kojima
authors.forename: Motoshi
authors.initials: M
authors.lastname: Suzuki
authors.forename: Yoshiko
authors.initials: Y
authors.lastname: Banno
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Nozawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Murate
mesh_terms: D000818:Animals; D018938:Caco-2 Cells; D005786:Gene Expression Regulation; D011905:Genes, ras; D006801:Humans; D051379:Mice; D009154:Mutation; D010739:Phospholipase D / Q000235:genetics*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000032:analysis; D016329:Sp1 Transcription Factor / Q000502:physiology*
chemical_list: D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D010739:Phospholipase D; C106801:phospholipase D1