Fig. 2.

5’ RACE analysis and PLD1 promoter analysis of DLD1 cells.

5’ RACE was performed to determine the transcription start site of PLD1 mRNA in DLD-1 cells as described in Materials and Methods. The right side illustrates several start sites (triangles) determined in our analysis by cloning and sequencing the band observed in the left side gel. An asterisk denotes the transcription start site available in the NCBI database. A solid triangle identifies the start site of exon 1 used in the present experiments. (b) and (c), PLD1 promoter analysis performed using various truncated luciferase vectors as illustrated in the left part of the figure. Using DLD-1 cells, a reporter assay was performed as described in Materials and Methods. In the lower part (c), data on a further truncation and the introduction of mutations into Sp1 sites are shown. M1 denotes the distal Sp1 site mutation (solid square), while M2 shows the proximal Sp1 site mutation. MD means the mutation of both Sp1 sites. Other motifs were also illustrated in the figure.