Fig. 5.

S2Lb and SDG2 associate over a large gene repertoire. a Size-exclusion chromatography of S2Lb-GFP complex size in S2Lb::S2Lb-GFP plant extracts. FPLC fractions were analyzed by anti-GFP immunoblot. Arrows indicate the elution peaks of molecular-weight standards in the same conditions. b Endogenous WDR5 co-immunoprecipitates with S2Lb-GFP in HMW fractions. Pooled fractions from samples in a were used for anti-GFP immunoprecipitation and analyzed using anti-GFP and anti-WDR5 antibodies. c IP-MS identification of S2Lb-GFP interacting proteins. The table gives the number of peptides from the indicated proteins detected using plant extracts from S2Lb-GFP plants but not from wild-type Col-0 plants in four biological replicates. d Co-immunoprecipitation assay on SDG2::MYC-SDG2;S2Lb::S2Lb-GFP plants with anti-GFP coated (+) or uncoated beads (−). Immunoprecipitated S2Lb-GFP and MYC-SDG2 proteins were detected by anti-GFP and anti-MYC immunoblots, respectively. e Chromatin extracts from S2Lb and SDG2 loss-of-function plants display similar defects in H3K4me3 global level. Immunoblot analysis of WT, s2lb-2, and heterozygote (HT) or homozygote (HM) sdg2-1 seedlings was performed using antibodies recognizing total histone H3 and H3K4me3. H3 is used as a loading control. f The heatmap shows S2Lb-GFP and MYC-SDG2 enrichment over S2Lb-GFP occupied genes (N = 4557). Genes are equally ranked from top to bottom in each line according to S2LB-GFP median enrichment. g Overlap between genes marked by H3K4me3 and genes occupied by MYC-SDG2 or S2Lb-GFP. The overlap between S2Lb-GFP and MYC-SDG2: × 5.7 p value < 0e+00; overlap between S2Lb-FP and H3K4me3: × 1.7 p value < 0e+00; overlap between MYC-SDG2 ad H3K4me3: × 1.6 p value < 0e+00. The corresponding gene IDs are listed in Additional files 4 and 7. h Median enrichment of S2Lb-GFP, MYC-SDG2, and H3K4me3 over S2Lb-GFP occupied genes (N = 4557). i Density matrix showing the co-occurrence of S2LB-GFP and MYC-SDG2 along S2Lb target genes (N = 4557). j Median enrichment of MYC-SDG2 on TAIR10 genes split into four classes ranked by expression level in wild-type seedlings