Figure 6

Transcription factors bind the endogenous P2X ₁ promoter. Formaldehyde cross-linked chromatin was prepared from PMA-treated MEG-01 cells and immunoprecipitated with antibodies to Sp1 (lane 4), Sp3 (lane 5), NF-1 (lane 6), TFIIB (lane 7), or in the absence of antibody (lane 3). PCR was performed with specific primers for the P2X₁, H4 and Hsp70 promoter and for the GAPDH coding region as a negative control. A sample representative of the total input chromatin (input DNA lane 1) was included in the PCR analysis. Lane 2 shows the supernatant of the 'unbound' sample. PCR products were between 282 and 983 bp in length. PCR cycle numbers were 31 for the P2X₁, H4 and Hsp70 promoter and 36 for the GAPDH coding region. Primer sequences are given in Table 3.