Figure 4.

The replication stress-induced FANCM-PCNA interaction is reduced by the FANCM PIP-box mutation. (A,B) Immunoflurescence images and (C) quantitation of the PLA assay showing that the HU-induced interaction between Flag-FANCM and PCNA is reduced by the FANCM PIP-box mutation. HeLa cells were transfected with either Flag-FANCM wildtype or the PIP-box mutant (L8S/W12R); and are either untreated (A) or treated with HU (B). The cells were co-stained with antibodies against Flag and PCNA. DNA was co-stained with DAPI. Two independent experiments were performed. In the quantitation plots each spot represents the number of PLA signals in an individual nucleus. In the experiment with untreated cells 157 nuclei expressing wildtype FANCM and 149 nuclei expressing the PIP mutant were analyzed. In the experiment with cells treated with HU 156 nuclei expressing wild type FANCM and 153 nuclei expressing the PIP mutant were analyzed.