Fig. 4.

Localization of NBS1 to nucleoli after expression of TCOF1 mutants. (A) Sequence alignment of TCOF1 regions containing putative ATM SQ phosphorylation sites from different species. The putative ATM phosphorylation sites are in red. (B) Representative images of U2OS cells expressing HA-TCOF1 wild-type or mutant proteins stained with antibodies against NBS1 (green) and the HA tag (red) after IR treatment (10 Gy). (C) Quantification of the percentage of U2OS cells expressing HA-TCOF1 wild-type or mutant proteins that exhibit nucleolar staining treated as in B.