Journal: Molecular cell
Article Title: Phospho-H1 decorates the inter-chromatid axis and is evicted along with Shugoshin by SET during mitosis
doi: 10.1016/j.molcel.2017.07.008
Figure Lengend Snippet: (A) Silver stain of Tandem Affinity Purification (TAP) of SET-complexes from iMEFs. CYTO: cytosol, SNE: soluble nuclear extract, CHR: chromatin pellet, NFH-SET: N-terminal FLAG-HA-SET, ENDO-SET: endogenous SET. (B) Venn diagram depicting top proteins identified from TAP-MS analysis of cytosolic and nuclear extracts prepared from mouse (iMEFs) and human (hTERT-RPE1) cells. Raw peptide count numbers are presented in Table S1. Only proteins with a cumulative peptide count of 10 or higher were included in the Venn diagram. (C) Volcano plot of quantitative-MS analysis of SET-associated proteins from mitotic extracts. SGOL1 and SGOL2 are highlighted in ellipses. Note that the plot represents proteins enriched in cytosolic and nuclear fractions combined. Histones enriched in the nuclear extracts are depicted separately in Figure 1H. (D) IF analysis on human chromosomes from WT RPE1 cells depicting co-localization of SET and SGOL2 at centromeres. Chromosomal arm staining is also observed for SET. Also see Figure S1E for another zoomed in chromosome. Scale bar =5 µm. (E) Glycerol gradient analysis of SET-complexes indicating co-elution of SET and SGOL2 at fraction 7, independent of PP2A (fraction 3). Traces of peak normalized intensities for each fraction is shown below. Also see Figure S1E for the same analysis with an alternate PP2A-B subunit. (F) (Top) Domain organization and constructs of SGOL2 and SET used in the pull-down assay. D-box, KEN-box: putative APC/C recognition domains, SGO: SGO domain. The asterisks in SET DIM represent point mutations that impaired dimerization. (Bottom) In vitro pull-down assay between GST-tagged N-terminal (1–650 a.a.) or C-terminal (651–1265 a.a.) regions of SGOL2 with SET, either WT or mutant in its dimerization domain (DIM) or in its acidic tail (ACID), indicating direct association of SET with the N-terminal region of SGOL2. Dimerization, but not the acidic tail, is required for SET binding. REP1 and REP2: experimental replicates. (G) Glycerol gradient separation of H1.2 complexes indicating co-elution with SET at fractions 7–9. Traces of peak normalized intensities for each fraction is shown below. Fraction 23 was omitted for clarity. (See also Figure S1I). (H) Quantitative MS data for histones co-purifying with SET in mitotic extracts. Linker histones are the most abundant histones associated with SET in the nuclear extracts. (See also Figure S1).
Article Snippet: Antibodies Antibodies for western blots were used at the following dilutions: rabbit anti-SET and goat anti-SET (Santa Cruz, 1:1000), rabbit anti-SGOL2 (Bethyl, 1:1000), mouse anti-SGOL1 (Abcam, 1:1000), rabbit anti-PP2A-B (Cell Signaling, 1:1000), rabbit anti-PP2A-B’ (Bethyl, 1:1000), mouse anti-H1 (Santa Cruz, 1:2500), rabbit anti-H3 and anti-H4 (Abcam, 1:5000), mouse anti-H3S10ph (Millipore, 1:1000), mouse anti-GAPDH (Genetex, 1:5000), rabbit anti-REPIN1 (Sigma, 1:1000), mouse anti-MPM2 (Millipore, 1:1000), rabbit anti-H1S/T18ph (Abcam, 1: 1000), rabbit anti-PAF1 and anti-LEO1 (Reinberg lab, 1:1000), Rabbit anti-H1S27ph (Sigma 1:1000), anti-H1S35ph (genetex, 1:1000).
Techniques: Silver Staining, Affinity Purification, Staining, Co-Elution Assay, Construct, Pull Down Assay, In Vitro, Mutagenesis, Binding Assay