TY - JOUR
T1 - Inhibition of NF-κB stabilizes gadd45α mRNA
AU - Zheng, Xue
AU - Zhang, Yadong
AU - Chen, Yu Quan
AU - Castranova, Vince
AU - Shi, Xianglin
AU - Chen, Fei
PY - 2005/4/1
Y1 - 2005/4/1
N2 - Growth arrest- and DNA damage-inducible protein α (gadd45α) is an important regulator for cell cycle, genomic stability, and cell apoptosis. In the present report, we demonstrated that NF-κB inhibition due to Ikkβ deficiency enhanced the stability of gadd45α mNRA. Using embryo fibroblast cells derived from wild type (wt) or Ikkβ gene knockout (Ikkβ-/-) mice, reverse transcription-polymerase chain reaction revealed a three- to fourfold increase of gadd45α mRNA in Ikkβ-/- cells compared with wt cells. The deficiency in Ikkβ substantially decreased basal NF-κB activity and increased accumulation of reactive oxygen species (ROS). However, such deficiency had no effect on the basal expression or activity of Akt, FoxO3a, p53, and c-myc that regulate the transcription of gadd45α gene positively or negatively. Analysis of gadd45α mRNA stability showed a ROS-dependent increase in the half-life of gadd45α mRNA in Ikkβ-/- cells. Immunoprecipitation experiments indicated an increased binding of a RNA stabilizing protein, nucleolin, to gadd45α mRNA in Ikkβ-/- cells. The binding of nucleolin to gadd45α mRNA could be prevented by the antioxidant, N-acetyl-cysteine. Thus, these data are the first to suggest that inhibition of Ikkβ-NF-κB signaling up-regulates the expression of gadd45α mNRA through a post-transcriptional, rather than a transcriptional, mechanism.
AB - Growth arrest- and DNA damage-inducible protein α (gadd45α) is an important regulator for cell cycle, genomic stability, and cell apoptosis. In the present report, we demonstrated that NF-κB inhibition due to Ikkβ deficiency enhanced the stability of gadd45α mNRA. Using embryo fibroblast cells derived from wild type (wt) or Ikkβ gene knockout (Ikkβ-/-) mice, reverse transcription-polymerase chain reaction revealed a three- to fourfold increase of gadd45α mRNA in Ikkβ-/- cells compared with wt cells. The deficiency in Ikkβ substantially decreased basal NF-κB activity and increased accumulation of reactive oxygen species (ROS). However, such deficiency had no effect on the basal expression or activity of Akt, FoxO3a, p53, and c-myc that regulate the transcription of gadd45α gene positively or negatively. Analysis of gadd45α mRNA stability showed a ROS-dependent increase in the half-life of gadd45α mRNA in Ikkβ-/- cells. Immunoprecipitation experiments indicated an increased binding of a RNA stabilizing protein, nucleolin, to gadd45α mRNA in Ikkβ-/- cells. The binding of nucleolin to gadd45α mRNA could be prevented by the antioxidant, N-acetyl-cysteine. Thus, these data are the first to suggest that inhibition of Ikkβ-NF-κB signaling up-regulates the expression of gadd45α mNRA through a post-transcriptional, rather than a transcriptional, mechanism.
KW - Gadd45α
KW - Ikkβ
KW - NF-κB
KW - Nucleolin
KW - mRNA stability
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U2 - 10.1016/j.bbrc.2005.01.105
DO - 10.1016/j.bbrc.2005.01.105
M3 - Article
C2 - 15721278
AN - SCOPUS:13844297055
SN - 0006-291X
VL - 329
SP - 95
EP - 99
JO - Biochemical and Biophysical Research Communications
JF - Biochemical and Biophysical Research Communications
IS - 1
ER -