FIG. 4.

A BRG1-based SWI/SNF complex appears to be responsible for HSF1-associated remodeling activity. (A) Nuclear fractions from the M2 (anti-FLAG) purification of a HeLa cell line control (lane 1) and GAL4-HSF wild type (lane 2) were compared in the supercoiling assay, both plus ATP. L, linear DNA; Sc, completely supercoiled DNA. (B) Nuclear fractions from M2 (anti-FLAG) purification of the GAL4-HSF acidic mutant, the GAL4-HSF phenylalanine mutant, and a HeLa cell line control were resolved by SDS-PAGE and assayed by Western blot analysis using the anti-BRG1 antibody (top panel) and the anti-FLAG antibody, (M5; Sigma) (middle panel). These fractions (lanes 3 to 8) were then compared to purified hSWI/SNF (lanes 1 and 2) in the supercoiling assay. L, linear DNA; Sc, completely supercoiled DNA. (C) Nuclear fractions from M2 (anti-FLAG) purification of the GAL4-HSF wild type, GAL4-HSF acidic mutant, and the GAL4-HSF phenylalanine mutant were compared to nuclear extract input. Samples were resolved by SDS-PAGE and assayed by Western blot analysis using the anti-hBRM antibody.