FIG. 4.

Mutant ABCDE fails to exit the DSB-associated nuclear compartment with normal kinetics. (A) V3 transfectants were treated (or not) with 7 μM bleomycin for 1 h on coverslips and were stained at the indicated time points as described in Materials and Methods. Average numbers of foci/cell are presented for each time point for the indicated cell strains. Only one clone for each mutant is depicted, but two independent clones for each mutant were tested with similar results. (B) V3 transfectants were treated (or not) with 140 μM bleomycin for 1 h. Cells were harvested either immediately or after 6 h of culture in fresh medium. A triton-insoluble nuclear fraction was isolated as described in reference 13 and analyzed by immunoblotting as indicated. Densitometric quantification of the immunoblot is presented in the bottom panel. This experiment is representative of three independent assays. wt, wild type.