Arid1a d2a8u

Protein lysates were quantified using the Micro BCA Protein Assay Kit (ThermoFisher) and a FlexSystem3 plate reader. Protein lysates were run on a 4–15% gradient SDS-PAGE gel (BioRad, Hercules, CA, USA) and transferred to the PVDF membrane using the TransBlot Turbo system (BioRad). Primary antibodies were used at the following dilutions: 1:1000 ARID1A (D2A8U) (12354, Cell Signaling, Danvers, MA, USA); 1:1000 β-Actin (8457, Cell Signaling); 1:1000 PGR (SAB5500165, Sigma); 1:1000 ESR1 (MCA1799, Bio-Rad), 1:100 BRG1 (sc-17796, Santa Cruz Biotechnology, Dallas, TX, USA); 1:1000 ARID1B (92964, Cell Signaling). Horseradish peroxidase (HRP) conjugated secondary antibodies (Cell Signaling) were used at a dilution of 1:2000. Clarity Western ECL Substrate (BioRad) was used for protein band visualization, and western blot exposures were captured using the ChemiDoc XRS+ imaging system (BioRad). Uncropped western blots are shown in Supplementary Figure S4.

Total protein was extracted from cells using cell lysis RIPA buffer and supplemented with a phosphatase and protease inhibitor cocktail; 60 µg of protein lysate was resolved by SDS–polyacrylamide gel electrophoresis (SDS-PAGE; 6%) and transferred to PVDF membranes, which were blocked with 5% non-fat milk in PBS-T and incubated overnight with the indicated antibody. The primary antibodies used are the following: anti-SMARCA4 (sc-17796, Santa Cruz Biotechnology, Dallas, TX, USA), SMARCA2 (D9E8B-XP, Cell Signaling Technology, Danvers, MA, USA), ARID1A (D2A8U, Cell Signaling Technology), ARID1B (ab57461, Abcam, Cambridge, UK), ARID2 (sc-166117, Santa Cruz Biotechnology), BRD9 (A303-781A, Bethyl Laboratories), and anti-BETA-ACTIN (A5441, Sigma Aldrich, Merck KGaA, Darmstadt, Germany). The membranes were then treated with HRP-conjugated anti-rabbit or anti-mouse secondary antibodies (P0448 and P0447, respectively, Dako, Agilent Technologies, Santa Clara, CA, USA). The target protein bands were visualized using Clarity Western ECL Substrate (BioRad, Hercules, CA, USA) and ImageQuant LAS4000 (GE Healthcare, Chicago, IL, USA). Protein bands were quantified using ImageJ software. We normalized the data with ACTB values and we transformed the data by applying the ‘log2 (normalized value +1)’.