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. Author manuscript; available in PMC: 2006 Feb 27.
Published in final edited form as: J Biol Chem. 2005 Mar 23;280(22):21004–21014. doi: 10.1074/jbc.M413191200

Fig. 4.

Fig. 4

RFX family of proteins repress COL1A1 promoter activity. A, RFX1 represses COL1A1 promoter construct. COL1A1 promoter construct (−311, 0.5 μg) was co-transfected with green fluorescent protein (0.1 μg) and increasing amounts of RFX1 constructs into FR cells. Luciferase activities were normalized by both protein concentration and green fluorescent protein fluorescence and expressed as a ratio compared with the empty vector control. Each experiment was repeated three times and values represent mean ± S.D. One-sample two-tailed t test was used to assess the statistical significance. At each dose tested, RFX1 significantly repressed COL1A1 promoter activity (*, p < 0.05). B, RFX5 represses the COL1A1 promoter construct. COL1A1 promoter construct (−311, 0.5 μg) was co-transfected with green fluorescent protein (0.1 μg) and increasing amounts of RFX5 constructs into FR cells. Luciferase activities were normalized by both protein concentration and green fluorescent protein fluorescence and expressed as a ratio compared with the empty vector control. Each experiment was repeated three times and values represent mean ± S.D. One-sample two-tailed t test was used to assess the statistical significance. At each dose tested, RFX1 significantly repressed COL1A1 promoter activity (**, p < 0.01). C, all three components of the RFX5 complex repress COL1A1 promoter activity better than individual members. COL1A1 promoter construct (−311, 0.5 μg) was co-transfected with green fluorescent protein (0.1 μg) and RFX5, RFXB, or RFXAP constructs individually or together into FR cells. Luciferase activities were normalized by both protein concentration and green fluorescent protein fluorescence and expressed as a ratio compared with the empty vector control. Each experiment was repeated three times and values represented mean ± S.D. One analysis of variance with post-hoc Scheffe test was used to assess the statistical significance. Co-transfection of three components of the RFX5 complex repressed COL1A1 promoter activity significantly more than each individual members (*, p < 0.05). D, IFN-γ represses the COL1A1 promoter construct in a dose-dependent manner. COL1A1 promoter construct (−311, 0.5 μg) was co-transfected with green fluorescent protein (0.1 μg) and increasing doses of IFN-γ into IMR-90 cells. Luciferase activities were normalized by both protein concentration and green fluorescent protein fluorescence and expressed as a ratio compared with the empty vector control. Each experiment was repeated three times and values represented mean ± S.D.