Fig. 6: Global constraining of mitotic chromosomes by nucleosome–nucleosome interactions. | Nature Communications

Fig. 6: Global constraining of mitotic chromosomes by nucleosome–nucleosome interactions.

From: Single-nucleosome imaging unveils that condensins and nucleosome–nucleosome interactions differentially constrain chromatin to organize mitotic chromosomes

Fig. 6

a Illustration of the effects caused by trichostatin A (TSA) and condensin depletion (KD)37. Chromosome cross-section view (top left). TSA treatment induces histone tail hyperacetylation and weakens nucleosome interactions (top right). Abnormal chromosome after condensin depletion (bottom left). TSA treatment of condensin-depleted cells results in greatly decompacted hyperacetylated chromatin, which is diffusely distributed throughout the cytoplasm (bottom right). b (left) Western blot of tail acetylated H3 and H4 from untreated (lane 1), SMC2 KD (2), 4 h TSA-treated (3) and 4 h TSA-treated SMC2 KD (4) HCT116 cells. H2B was used as a control. (right) Box plots (whiskers, maxima/minima; bounds of box, first/third quantiles) of SMC2-mClover signal. A.U. means arbitrary unit. Gray and black bars show mean and median values. Data from n = 27 (control), n = 20 (SMC2 KD), n = 24 (TSA), n = 16 (SMC2 KD + TSA) cells are shown. ***P < 0.0001 by Wilcoxon rank sum test (two-sided). c MSD plot (±SD among cells) of JF549-labeled nucleosomes in the mitotic HCT116 cells with condensins I and II depletion (SMC2 KD, blue, n = 20), condensins I and II depletion +5 µM TSA treatment (4 h) (SMC2 KD + 5 µM TSA, purple, n = 16), 5 µM TSA treatment (5 µM TSA, magenta, n = 24), and untreated control (control, black, n = 27). The Kolmogorov-Smirnov test (two-sided) was used. *** P ≤ 0.0005 for control versus SMC2 KD + 5 µM TSA (P = 7.5 × 10−12), control versus SMC2 KD (P = 2.2 × 10−8), control versus 5 µM TSA (P = 2.4 × 10−7). Not significant (N.S.) for SMC2 KD versus 5 µM TSA (P = 0.11). MSD exponents and AC values from Supplementary Fig. 8 are also shown. d Fluorescent images of FA-fixed HCT116 cells with SMC2-mAID-mClover expressing H2B-Halo; H2B-Halo-JF549 (top), SMC2-mClover (middle), and merged images (bottom). From left to right, untreated control, condensins I and II depleted cell with IAA addition, TSA-treated cell, and TSA-treated cell with condensins I and II depletion.

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