FIG. 4.
UBMs are required for optimal association of REV1 with replication factories in cells exposed to UV radiation. (A) MRC5 cells were transfected with plasmids encoding full-length or deletion mutants of eGFP-REV1 as indicated. Twenty hours after transfection, cells were UV irradiated (10 J/m2) (bottom panel) and incubated for 8 to 16 h before fixation with paraformaldehyde. The distribution of REV1 or deletion mutants (as indicated) was observed directly by autofluorescence of eGFP. The images show unirradiated (top) or UV-irradiated (bottom) transfected cells. (B) REV1 focus formation after UV irradiation. MRC5 cells were transfected with a panel of eGFP-REV1 mutants and incubated for 20 h. Cells were irradiated with 10 J/m2 UVC radiation and further incubated for 8 h. The proportion of eGFP-REV1 expressing cells in which the protein was localized in nuclear foci was determined. All experiments were carried out in triplicate. Error bars indicate the standard error. Note that the result for BRCTΔ cells was extracted from reference 7.