Fig. 2.

Rap80 interacts with Abraxas through the AIR domain, and both UIM and AIR domains of Rap80 are required for optimal Rap80 foci formation. (A) The indicated Rap80 mutants were generated in a GFP–SV40 NLS N-terminal Rap80 fusion construct and used to examine foci formation as well as Abraxas and Brcc36 binding. (B) U2OS cells stably expressing GFP-tagged Rap80 and mutant proteins were either untreated or treated with IR, incubated at 37°C for 2 h, fixed, and stained with antibodies against GFP. At least 400 cells were counted for quantification. Cells that contained >10 foci were counted as positive. (C) 293T cells were transiently transfected with plasmids expressing the GFP-tagged Rap80 fusion proteins in A. After 40 h, cell lysates were prepared and immunoprecipitated (IP) with antibodies against Abraxas. WB indicates Western blot.