FIG 5.

ATR levels are reduced in ERH-deficient cells. (A) U2OS cells expressing nontargeting and ERH siRNAs were collected at 72 h posttransfection and lysed, and immunoblot analysis was performed for the indicated proteins. Data from a representative experiment are shown, but quantitative immunoblotting demonstrated statistically significant decreases in the levels of ATR, RAD50, TOPBP1, ATRIP, and MRE11 in ERH-depleted cells. (B) Cells were transfected with siRNA as indicated, total RNA was extracted and reverse transcribed into cDNA, and qPCR was performed to analyze the fold differences of mRNA levels in ERH-depleted cells compared to those of nontargeting controls. (* denotes a P value of <0.05. ** denotes a P value of <0.01.) (C) Cells were transfected with siRNA as indicated, and ATR levels in nuclear soluble and chromatin fractions were examined by immunoblotting. ORC2 is included as a loading control for chromatin fractions.