Figure 7.

Effect of over-expressing CtBP2 on the repression of the Fgf-3 promoter by SOX6 in differentiated F9 cells. (A) Differentiated F9 cells were co-transfected with the p(4Ax3)tkLuc reporter together with effector plasmids for the expression of SOX6, CtBP2 or SOX6 and CtBP2. Relative luciferase activities were normalised to the value obtained with the vector alone. (B) Endogenous expression of Sox6 and CtBP2 mRNAs in F9 cells. Poly(A)⁺ RNA (1 µg) from undifferentiated F9 (uF9) and differentiated F9 (dF9) cells was analysed by northern blotting using ³²P-labelled Sox6, CtBP2 and EF1α as a control for RNA loading. Positions of 28S and 18S ribosomal RNAs are indicated to the right of each panel. (C) SOX6 deletion mutant lacking PLNLSS does not repress transcription from the Fgf-3 promoter. Differentiated F9 cells were co-transfected with one of the reporter plasmids and an effector plasmid for expression of SOX6 or SOX6del. Relative luciferase activities are shown. Amounts of DNAs for transfection are the same as those in Figure 3.