Journal: Oncogene
Article Title: BMP- specific SMADs function as novel repressors of PDGFA and modulate its expression in ovarian granulosa cells and tumors
doi: 10.1038/onc.2012.392
Figure Lengend Snippet: SMAD1/5 expression antagonizes Sp1 induction of PDGFA promoter. (A) COV434 cells were transiently co-transfected with 1 μg of -881:luc of the human PDGFA promoter and 0.5 μg of Sp1 and SMAD1/5 along with the renilla luciferase control plasmid (pRL-TK). Forty-eight hours after transfection, the cells were lysed and assessed for luciferase activity. Data are presented as the ratio of firefly luciferase to renilla. (B) Representative Western blot of whole cell lysates from COV434 cells transfected with either pcDNA3.1 or Flag-tagged SMAD1/5 expression plasmids and blotted with mouse anti-FLAG M2 antibody and mouse anti-β-actin antibody (loading control). (C) ChIP analysis in COV434 cells transfected with pcDNA3.1 or Flag-tagged SMAD1/5 expression plasmids. Chromatin cross-linked protein DNA complexes were immunoprecipitated with either anti-Sp1 antibody or with non-specific IgG and the PDGF-A promoter amplified by real-time PCR using locus specific primers. (D) SMAD1/5 represses the wild-type PDGFA promoter (-261:luc) but not the promoter bearing a mutation in the SMAD1/5 binding site (-261mutA: luc). COV434 cells were transiently co-transfected with 1 μg of -261:luc (control) or -261mutA: luc (mutant) and 0.5 μg of Sp1 and SMAD1/5 along with the renilla luciferase control plasmid (pRL-TK). Forty-eight hours after transfection, the cells were lysed and assessed for luciferase activity. Data are presented as the ratio of firefly luciferase to renilla. Different letters above the bars indicate statistically different means by ANOVA and post hoc analysis (n=4; P< 0.05).
Article Snippet: Following transfer and blocking in 5% nonfat dry milk in Tris-buffered saline containing 0.1% Tween-20 (TBST) for one hour, the membrane was then incubated overnight at 4 °C with rabbit anti-phospho-Smad1/5 (Ser463/465) antibody (Cell Signaling, 41D10) diluted at 1:1000 or mouse anti-human SMAD1 antibody (Biomatrix research, BMR 00479) diluted at 1:500 or rabbit anti-human PDGF-A antibody (Santa Cruz, N-30) diluted at 1:500 or mouse anti-FLAG M2 antibody (Sigma- Aldrich, A8592) diluted at 1:1000 or mouse anti-β-actin antibody (Sigma- Aldrich, A5316) diluted at 1:10,000.
Techniques: Expressing, Transfection, Luciferase, Control, Plasmid Preparation, Activity Assay, Western Blot, Immunoprecipitation, Amplification, Real-time Polymerase Chain Reaction, Mutagenesis, Binding Assay