Fig. 7: USP11 deubiquitylates PRMT1, increasing MRE11 methylation.

a PRMT1 is ubiquitylated in 293T cells as determined by MultiDSK pulldown. DSK mut = MultiDSK that cannot bind ubiquitin (representative image of n = 3 independent biological experiments). b PRMT1 ubiquitylation status is USP11-dependent. 293T-pTRIPZ-shCTRL or shUSP11 cells were transfected with the indicated constructs and treated with doxycycline for 48 hrs. PRMT1 ubiquitylation was determined by MultiDSK pulldown (representative image of n = 3 independent experiments). c PRMT1 ubiquitylation is decreased in G2/M arrested cells in a USP11-dependent manner. HeLa-pTRIPZ-shUSP11 cells were transfected with the indicated constructs and doxycycline was added for 72 hrs. Ro-3306 (9 μM) was added 20 hrs prior to lysis and ubiquitylation status was determined by MultiDSK pulldown (representative image of n = 3 independent experiments). d MRE11 methylation is increased in G2/M arrested cells in a USP11 dependent manner. HeLa myc-MRE11/pTRIPZ-shCTRL or shUSP11 cells were treated with doxycycline for 48 h and then Ro-3306 (9 μM) for a further 20 hrs. Levels of MRE11 methylation were determined by myc-ADMA PLA. Data are from three independent biological experiments, with >75 nuclei scored per repeat (medium PLA foci for shCTRL (+Ro-3306) and shUSP11 (+Ro-3306) were 87 and 54, respectively; Mann–Whitney n₁ = 243; n₂ = 234; p < 0.0001; two-tailed). e Stable knockdown or overexpression of USP11 does not change PRMT1 protein levels in MCF7 and MDA-MB-231 cells. Representative image of n = 3 independent experiments. f USP11 but not PRMT1 expression levels are upregulated in S/G2 cells. 293T cells were synchronised by double thymidine block, released into complete media and harvested at the time points indicated. Cyclin A levels indicate cells in the S/G2 phase (representative image of n = 2 independent biological experiments). g Proposed model of cross-talk between arginine methylation, deubiquitylation and the control of DNA end-resection. USP11 levels increase in the S/G2 phase of the cell cycle providing substrate for PRMT1 to methylate USP11 at R433. In turn, methyl-USP11 catalyses the deubiquitylation of PRMT1, enhancing PRMT1-MRE11 interactions and promoting MRE11 methylation in S/G2 cells. This stimulates DNA end-resection that commits a cell to HR-mediated repair of DSBs. Unmethylated USP11 deubiquitylates PALB2. Uncropped blots and raw graphical data provided as a Source Data file.