Effect of DMSO-induced differentiation of HL-60 cells on levels of PU.1 protein.

(A) EMSA of DMSO-induced cells. HL-60 cells were incubated with or without 1.25% DMSO for 38 hours, and nuclear extracts were prepared. EMSA was carried out with 5 μg nuclear extracts using the³²P-labeled p40^phox PU.1a DNA probe. Specific PU.1-containing complexes are indicated by the arrow. (B) Immunoblot analysis of DMSO-induced cells. HL-60 cells were incubated with or without 1.25% DMSO for 38 hours, and equal amounts of protein from whole cell lysates were separated by SDS-PAGE and analyzed by immunoblotting with specific antibody to PU.1. The 42-kd form of the protein is indicated by the arrow. The slower-migrating band probably corresponds to a hyper-phosphorylated form of the protein.67 68