cPKCs, lipins, and Dullard boost mitotic lamin B1 disassembly. (A) HeLa cells stably coexpressing H2B-mCherry and GFP–lamin B1 were transfected with siRNA oligos against the indicated transcripts or control oligos before quantitation of mean mitotic lamin B1 disassembly as described in Fig. 2. (B) Mean mitosis durations of cells quantified in A. (C) HeLa cells stably coexpressing H2B-mCherry and GFP–lamin B1 were synchronized by double thymidine arrest. Approximately 30–60 min before mitotic entry cells were treated with DMSO (mock), 4 µM U73122 (PLC inhibition), or 200 µM propranolol (lipin inhibition), and mean lamin B1 disassembly was determined as in A. (D) Mean mitosis durations of cells quantified in C. The data represent the mitotic events from two replicate experiments. n > 200 for each condition with ***, P < 0.0001 (U test; Table S2). Dotted lines indicate mean control timing. Error bars indicate 95% confidence intervals.