Figure 5.

EMSA of recombinant ATF3ΔZip2. Full-length ATF3 and ATF3ΔZip2 were expressed as GST-fusion proteins as described in the Materials and Methods. (A) Purified GST–ATF3 fusion protein was analyzed by western blot using monoclonal anti-GST antibody. Lane 1, GST-full ATF3; lane 2, GST–ATF3ΔZip2; lane 3, GST. (B) Recombinant ATF3 proteins were assayed for their DNA binding activity by EMSA as detailed in the Materials and Methods. Lane 1, probe only; lane 2, 2.5 µg GST–full-length ATF3; lanes 3–5, 5 µg GST–full-length ATF3 in the absence (lane 3) or presence of wild-type ATF/CRE sequence (lane 4) and mutated sequence (lane 5), respectively; lanes 6 and 7, 2.5 and 5 µg GST–ATF3ΔZip2; lanes 8 and 9, 2.5 and 5 µg GST.