Extended Data Fig. 7: MLL1 enzymatic activity is required for AurkB activity at kinetochores.
From: Non-canonical MLL1 activity regulates centromeric phase separation and genome stability
(a-b) Immunofluorescence for AurkBpT232 (a) or Dsn1pS109 (b) in HeLa cells treated with siRNAs or inhibitors as indicated on top. DNA was visualized by Hoechst. The specific Dsn1pS109 signal was highlighted in the dashed rectangle. Scale bar, 10 μm. Quantification of fluorescence intensity for AurkBpT232 and Dsn1pS109 is shown on the right. Average intensity from n = 17 or 19 (siCon in a or b, repectively), n = 12 or 15 (siMLL1 in a or b, respectively), n = 20 or 14 (DMSO in a or b, respectively), n = 15 (ZM447439, MM-589, or MM-599 in both a and b) cells was presented for each condition. Standard deviation was presented as error bar. The p value was calculated by comparing to corresponding controls using two-tailed unpaired Student’s t-test. n.s, p > 0.05. (c) Immunofluorescence for AurkB pT232 (left) or Knl1 pS60 (right) in Mll1 set+/+ or Mll1 set∆/∆ MEFs. Centromere and DNA was visualized by ACA and Hoechst, respectively. Representative images from three independent experiments were presented. Scale bar, 10 μm. Quantification of signals of respective phosphorylated proteins is shown on the right. The line represents average from >120 kinetochore areas in 12 cells. The p value was calculated using two-tailed unpaired Student’s t-test. (d) Immunofluorescence for Dsn1 pS109 and Borealin in cells treated control, MLL1/KMT2A or KMT2B siRNAs. DNA was visualized by Hoechst. Representative images from two independent experiments were presented. Scale bar, 10 μm. Dashed rectangle was used to highlight specific Dsn1 pS109 signals.
