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. 2011 Aug;31(16):3208–3222. doi: 10.1128/MCB.05337-11

Fig. 9.

Fig. 9.

In vivo evidence of zinc fingers of SP1 and the basic leucine zipper of C/EBPβ required for protein complex formation to activate hPRLR hPIII promoter activity in ERα-positive (MCF-7A2) cells. (A) On the left, hPIII promoter activity was determined in MCF-7A2 cells transiently transfected with siRNA (30 nM) from coding region of SP1, C/EBPβ, or ERα. On the right is a diagram of the experimental procedure. (B) hPIII promoter activity was determined in MCF-7A cells transiently transfected with siRNA from the noncoding region of SP1 followed by vector alone (pcDNA-V5), wild-type SP1-V5, or the deletion of three zinc finger motifs (Sp1ΔZF-V5). (C) hPIII promoter activity was determined in MCF-7A cells transiently transfected with siRNA from the noncoding region of C/EBPβ followed by vector alone (pcDNA-V5), wild-type C/EBPβ-V5, or the deletion of both the basic region (BR) and the leucine zipper (LZ) (C/EBPβΔBR&LZ-V5). Scramble siRNA was used as a negative control. The inset shows a Western blot of endogenous SP1, C/EBPβ, or ERα in cell lysates after 4 days of transfection. β-Actin was used as the loading control.