FIGURE 6.

COUP-TFII cooperates with CREB in the control of renin gene expression. Calu-6 cells were transfected with nontargeting siRNA as control (siControl) or with COUP-TFII sequence-specific siRNA (siCOUP-TFII), CREB sequence-specific siRNA (siCREB), or a combination of COUP-TFII and CREB siRNAs (siCOUP-TFII+siCREB). A, efficacy of the CREB knockdown. Protein extracts were probed in Western blots with CREB and β-actin (internal control) antibodies. See Fig. 3B for the efficacy of the COUP-TFII knockdown. B, effect of the deficiency of COUP-TFII, CREB, or both on renin gene expression. Renin and human β-actin (internal control) mRNA levels were quantified by real-time PCR. C, specificity of the knockdown. COUP-TFI and human β-actin (internal control) mRNA levels were quantified by real-time PCR. D, top, COUP-TFII expression is similarly diminished when COUP-TFII alone or COUP-TFII and CREB are knocked down. Bottom, CREB expression is similarly diminished when CREB alone or COUP-TFII and CREB are knocked down. COUP-TFII, CREB, and human β-actin (internal control) mRNA levels were quantified by real-time PCR. The data shown are means ± S.E. (error bars). *, p < 0.05. NS, not significant.