Fig. 1. LSD1 localization on ALT telomeres requires TERRA.

a Total TERRA levels were evaluated by northern-dot-blot assay, following transient knockdown of TERRA in U2OS for 24 and 48 h (n = two independent experiments). b TERRA levels from chromosome 10, 13, 15, 20 were quantitated by qRT-PCR, following transient knockdown of TERRA in U2OS for 48 h (n = three independent experiments, two-tailed unpaired t test). c Representative images and d quantification of telomere clustering from DNA FISH after siTERRA in U2OS cells stably expressing TRF1-FokI with treatment of 4-Hydroxyestradiol (4-OH, 6 h) (n = 50 cells for FokI^WT siCtr, n = 69 cells for FokI^WT siTERRA, n = 58 cells for FokI^D450A siCtr, n = 76 cells for FokI^D450A siTERRA over two independent experiments, two-tailed unpaired t test). e Representative images and f quantification of APB bodies (defined by PML and telomere FISH colocalization) after siTERRA in FokI cells (n = 110 cells for siCtr, n = 122 cells for siTERRA over three independent experiments, two-tailed unpaired t test). g Representative images and h quantification of Edu foci on telomeres after siTERRA in FokI cells (n = 51 cells for siCtr, n = 70 cells for siTERRA over two independent experiments, two-tailed unpaired t test). i Representative images for GFP-LSD1 and GFP-FUS and j quantification of telomeric localization for GFP-tagged LSD1, FUS, NONO, RBXP, hnRNPUL1, and immunostained EZH2 with siControl and siTERRA in U2OS cells (more than 100 cells per group, n = three independent experiments, two-way ANOVA). k ChIP-qRCR assay was performed to detect telomeric LSD1 with or without siTERRA from indicated chromatin U2OS cells synchronized in G2 (n = three independent experiments, one-way ANOVA). Error bars are mean ± SEM. NS not significant. Source data are provided as a Source Data file.