Table I.

Quantification of changes in ubiquitylation of H2AX

Cells and treatment	u-H2AX/H2AX no IR	uγ-H2AX/γ-H2AX + IR
Ctrl shRNA U2OS	1.0	1.0
BMI1 shRNA1 U2OS	0.40	0.10
BMI1 shRNA2 U2OS	0.68	0.34
WT MEFs	1.0	1.0
BMI1 KO MEFs	1.03	0.14
RNF8 KO MEFs	1.04	0.63
Ctrl shRNA RNF8 KO	1.0	1.0
BMI1 shRNA1 RNF8 KO	0.68	0.18
BMI1 shRNA2 RNF KO	0.48	0.23

Cells were treated as in Fig. 5. The intensity of the H2AX and uH2AX were analyzed and the ratio between the two bands was determined. The ratio was then normalized relative to the control condition. In IR-treated cells, the same approach was used to quantify the ratio between ubiquitylated and parent forms of γ-H2AX.