The RNA transport factor PHAX is required for proper histone H2AX expression and DNA damage response

Reduction in H2AX mRNA levels by knockdown of PHAX. (A) U2OS cells were transfected with the indicated siRNAs, followed by UV-irradiation (20 J/m²). After 6-h incubation, the indicated mRNA levels were determined by qRT-PCR analysis. (B) U2OS cells were transfected with the indicated siRNAs. After 48-h incubation, the indicated mRNA levels were similarly determined. (C) U2OS cells were cotransfected with siPHAX and a PHAX-expressing plasmid. After 48-h incubation, the indicated mRNA levels were similarly determined. (D) The indicated mRNA levels in siPHAX-transfected cells were determined by qRT-PCR analysis and were expressed in the form of a heat map. Data are the means ± S.D. (n = 3–4). (**) P < 0.001.