ChIP Assay for MAOA Promoter Binding

A ChIP assay kit (Beyotime) was used to detect the binding amount of Sp1 or R1 with the MAOA promoter. Briefly, cells were crosslinked with 1% formaldehyde, sonicated with PBS containing 1 mM phenylmethylsulfonyl fluoride, and centrifuged at 12,000× g for 5 min. Equal amounts of total proteins were added anti-IgG, anti-R1, and anti-Sp1 antibodies, respectively. On the second day, protein A/G beads were added to bind the antibody-target protein-DNA complex. The precipitated complexes were washed and eluted to obtain the enriched target protein-DNA complex. The obtained complexes were purified with a DNA purification kit (Beyotime) and then detected with Real-time PCR. The methods of analyzed values were described previously (Jia et al., 2020a (link), b (link)).