The SUMO machinery is released from chromatin in senescent cells. (A) Comparison of SUMO1 association with Pol II, H3K4me3, H3K27me3, and H3K9me3 in proliferating (P) and HRASG12V-induced senescent (S) WI38 cells. (B) ChIP-qPCR for SUMO1 in proliferating (P), HRASG12V-induced senescent (RAS), and replicative senescent (RS) WI38 cells on MTBP/MRPL13 and FOS promoters. (C) Proliferating and senescent cells were fractionated, and the presence of the indicated proteins in each fraction was quantitated by Western blot. Equal amounts of proteins were loaded for total lysate, Cyt (cytoplasmic fraction), SNE (soluble nuclear extract), and pellet (insoluble fraction). (D) Plots showing peak density in proliferating (red) and senescent (blue) cells over chromosome 6. (E) Scatter plot comparison of differential gene expression as measured by RNA-seq and differential occupancy of SUMO1 (left) or SUMO2 (right) (peak height fold change) in proliferating versus senescent cells. Differential expression is shown as log2 of reads per RPKM.
