Fig. 2.

Reduced expression levels and activities of the rare FANCA variants. a Western blot analysis of the protein expression levels of wild-type FANCA and two altered proteins (R591Q and E1296G). An equal amount of indicated FANCA expression plasmids was co-transfected with pEGFP-N2 into U2OS cells. The densitometric units of altered FANCA proteins were normalized to that of the wild-type FANCA. Values are expressed as mean ± SD, N = 4. GFP was used to evaluate the transfection efficiency, and β-actin was used as a loading control. b Western blot analysis of mono-ubiquitinated FANCD2 in U2OS cells transfected with indicated FANCA expression plasmids with or without MMC (2 μM) treatment for 24 h. The densitometric units show the ratios of mono-ubiquitinated FANCD2 to unubiquitinated FANCD2, normalized to that of cells transfected with empty vector without MMC treatment. Values are expressed as mean ± SD, N = 4. β-Actin was used as a loading control. MMC, mitomycin C. *P < 0.05; **P < 0.01; ***P < 0.001