Fig 1: O-GlcNAcylation of SOX2 at S248 alters protein-protein interactions.(A) Interaction diagram of a subset of SOX2 interactors that exhibit differential association with 3xF-SOX2S248A relative to 3xF- SOX2WT. Color of circles indicates with which SOX2 proteoform a protein preferentially interacts. Interaction diagram based on high confidence, experimental interactions identified by STRING. (B), Anti-FLAG IP-WB for SOX2, PARP1, GATAD2B, and SMARCA4 in fSOX2-Tg and fS248A-Tg cells. (C) Heatmap of median enrichment values of NuRD subunits that preferentially associate with 3xF-SOX2WT or 3xF-SOX2S248A as determined by quantitative mass spectrometry (n=3). (D) Western blot analysis of in vitro interaction between SOX2 +/- O-GlcNAcylation and PARP1. Bio-SOX2 and His-OGT were incubated with and without UDP-GlcNAc, Bio-SOX2 purified away from OGT and UDP-GlcNAc using streptavidin beads and incubated with GST-PARP1. Western blots examine proteins associated with streptavidin beads. Comparable amounts of input and pull down were loaded for all blots, except O-GlcNAc, in which more material was loaded in the pull down lanes. WB, Western blot; GST, glutathione S-transferase tag; Bio, biotinylated Bio tag; His, polyhistidine tag. (E) Flow chart outlining scheme for D.DOI: http://dx.doi.org/10.7554/eLife.10647.021