1. Abraxas binds to BRCT–PALB2(L21P) and is involved in the recruitment of this fusion protein or of endogenous PALB2 to sites of DNA damage.
Abraxas binds to BRCT–PALB2(L21P) and is involved in the recruitment of this fusion protein or of endogenous PALB2 to sites of DNA damage. (A) BRCT–PALB2(L21P), PALB2 or the empty vector alone were stably expressed in U2OS cells along with an N-terminal Flag-HA epitope tag. CtIP, FANCJ, Abraxas, BRCA2 or Flag-HA tagged PALB2 constructs were detected by immunoblotting as indicated. Inputs represent 10% of the extracts utilized for immunoprecipitation (IP). (B) Immunoblots demonstrating siRNA-mediated depletion of different BRCA1 BRCT-binding proteins in U2OS-DR cells. Actin is shown as a loading control. Similar results were obtained in U2OS cells lacking the HR reporter construct. (C,D) Quantification of the assembly of the Flag-HA-BRCT–PALB2(L21P) fusion protein (C), detected with anti-HA antibodies, or endogenous PALB2 (D) into foci in U2OS-DR and U2OS cells, respectively, following depletion of various BRCA1 BRCT-binding proteins. Cells were fixed 16 h after exposure to 10 Gy IR. The difference in foci formation in cells depleted of Abraxas was statistically significant, as compared to transfection with other siRNAs (C: P<0.001; D: P<0.005). Each value represents the mean ± SD of three counts of 150 or more cells from the same coverslip (C,D).
Fan Zhang et al. J Cell Sci 2012;125:
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