Fig 1: HSA mutant interacts with a subset of the SWI/SNF complex members bound by WT BRG1 and is necessary for increased BCL7 protein levels.(A) Co-immunoprecipitation–mass spectrometry data comparing the SWI/SNF complex members identified between the iBRG1 line and the i?HSA cell line. The SWI/SNF complex protein name is found in the first column, followed by the percent of the protein covered by the mass spectrometry experiment, the number of unique peptides identified and the MS score, and the average spectral counts from each protein pulled down by the V5 antibody used to detect iBRG1 or i?HSA in the second column. Each column represents the average from three biological replicates. The proteins are colored from blue to white by spectrum average with white being the lowest (zero) and blue being the highest. The protein names highlighted in purple and crossed out were not found in the i?HSA pulldown. (B) Co-immunoprecipitation of SWI/SNF proteins from iBRG1 or i?HSA cells after 24 h of doxycycline treatment. The top rows indicate the 5% input, or the antibody used for the immunoprecipitation (IgG, V5, BCL7B, or BAF53a), and the labels on the right indicate the antibody used for detection on the immunoblot (top: V5; bottom: BAF53a). (C) Co-immunoprecipitation displaying the interaction between BCL7C and BRG1 in iBRG1 or i?HSA cells after 24 h of doxycycline treatment. The top rows indicate the 5% input, or the antibody used for the immunoprecipitation (top: V5; bottom: BCL7C), and the label on the right indicates the antibody used for detection on the immunoblot (V5). (D) Co-immunoprecipitation displaying the interaction between BAF155 and iBRG1 or i?HSA. The top rows indicate the 5% input, or the antibody used for the immunoprecipitation (IgG, V5, BAF45b, or BAF155), and the label on the right indicates the antibody used for the detection on the immunoblot (V5 or BAF155). (E) Co-immunoprecipitation displaying interaction between GLTSCR1L and BAF45b with iBRG1 or i?HSA. The top rows indicate the 5% input, or the antibody used for the immunoprecipitation (IgG, V5, BAF45b, or GLTSCR1L), and the label on the right indicates the antibody used for the detection on the immunoblot (V5 or GLTSCR1L). (F) Immunoblot detection of BRG1, BCL7A, BCL7B, and tubulin (left) or BRG1, BCL7C, and GAPDH (right) protein levels with increasing levels of iBRG1 or i?HSA expression by doxycycline treatment. Each blot contains equivalent levels of protein per lane, and the levels of doxycycline used for 24 h increase from left to right. (G) Differential salt extraction of BRG1 in iBRG1 or i?HSA cells after 24 h of doxycycline treatment. Left is the immunodetection of BRG1 or i?HSA in doxycycline-treated conditions. Right is the average fraction of the total protein extracted in each salt concentration in iBRG1 or i?HSA cells from two replicates. Error bars represent the SD. (H) Differential salt extraction of BCL7C in iBRG1 or i?HSA cells after 24 h of doxycycline treatment. Left is the immunodetection of BRG1 or i?HSA in doxycycline-treated conditions. Right is the average fraction of the total protein extracted in each salt concentration in iBRG1 or i?HSA cells from two replicates. Error bars represent the SD. (I) Differential salt extraction of BAF53a in iBRG1 or i?HSA cells after 24 h of doxycycline treatment. Left is the immunodetection of BRG1 or i?HSA in doxycycline-treated conditions. Right is the average fraction of the total protein extracted in each salt concentration in iBRG1 or i?HSA cells. Error bars represent the SD. (J) Differential salt extraction of BAF155 in iBRG1 or i?HSA cells after 24 h of doxycycline treatment. Left is the immunodetection of BRG1 or i?HSA in doxycycline-treated conditions. Right is the average fraction of the total protein extracted in each salt concentration in iBRG1 or i?HSA cells. Error bars represent the SD.Source data are available for this figure.