USF1 and USF2 bind to the E1 in the P2 promoter of the PC gene.

<p><b>A.</b> Nucleotide sequences of M4, M5 and M5 pmut E2 probes. E-box and GC-box are underline. <b>B,</b> EMSA of M4 probe with INS-1 832/13 nuclear extract. Lane 1, M4 probe alone; lane 2, probe incubated with nuclear extract; lanes 3–4, nuclear extracts pre-incubated with anti-USF1 or anti-USF2 antibody before the probes were added into the reaction, respectively. Lanes 5–6, probe incubated with nuclear extract of INS-1 832/13 overexpressing USF1 or USF2, respectively. Lanes 7 and 8, nuclear extracts of INS-1 832/13 overexpressing USF1 pre-incubated with anti-USF1 antibody or overexpressing USF2 pre-incubated with anti-USF2 antibody before the probe was added into the reaction, respectively. Lane 9, INS-1 832/13 nuclear extract pre-incubated with anti-ChREBP antibody before the probe was added into the reaction. <b>C.</b> EMSA of M5 pmut E2 probe with an INS-1 832/13 nuclear extract. Lane 1, M5 pmut E2 probe alone; lane 2, probe incubated with nuclear extract; lanes 3–5, nuclear extracts pre-incubated with anti-USF1, anti-USF2 or anti-ChREBP antibody before the probes were added into the reaction, respectively. Arrows represent DNA-protein complexes.