Fig. 6.
Absence of the PU.1/Pip complex in CD20-negative cell lines. (A) EMSA was performed with 0.5 ng of the CD20#2 probe or the SV40 PU.1 probe (lane 9) and in vitro translated PU.1 and Pip (lane 1) or nuclear extracts from B-cell lines PB697 (lanes 2,3, and 4), RPMI 8226 (lanes 5 and 6), or NALM-6. In vitro translated proteins were added to the gel shift reactions as indicated. NS denotes a nonspecific band. (B) PU.1 immunoblot. A total of 100 μg of whole cell lysate of the indicated cell line (lanes 1 to 7) or 6 λ of 35S-labeled in vitro translated mouse PU.1 (lane 8) were fractionated by SDS-PAGE and immunoblotted with a rabbit PU.1 antiserum. Autoradiography was performed with the same membrane to verify the position of 35S-labeled PU.1 (lane 9).