Post-transcriptional regulation of RNase-L expression is mediated by the 3'-untranslated region of its mRNA

TY - JOUR

T1 - Post-transcriptional regulation of RNase-L expression is mediated by the 3'-untranslated region of its mRNA

AU - Li, Xiao-Ling

AU - Andersen, Jesper Bøje

AU - Ezelle, Heather J

AU - Wilson, Gerald M

AU - Hassel, Bret A

PY - 2007/3/16

Y1 - 2007/3/16

N2 - RNase-L mediates critical cellular functions including antiviral, pro-apoptotic, and tumor suppressive activities; accordingly, its expression must be tightly regulated. Little is known about the control of RNASEL expression; therefore, we examined the potential regulatory role of a conserved 3'-untranslated region (3'-UTR) in its mRNA. The 3'-UTR mediated a potent decrease in the stability of RNase-L mRNA, and of a chimeric beta-globin-3'-UTR reporter mRNA. AU-rich elements (AREs) are cis-acting regulatory regions that modulate mRNA stability. Eight AREs were identified in the RNase-L 3'-UTR, and deletion analysis identified positive and negative regulatory regions associated with distinct AREs. In particular, AREs 7 and 8 served a strong positive regulatory function. HuR is an ARE-binding protein that stabilizes ARE-containing mRNAs, and a predicted HuR binding site was identified in the region comprising AREs 7 and 8. Co-transfection of HuR and RNase-L enhanced RNase-L expression and mRNA stability in a manner that was dependent on this 3'-UTR region. Immunoprecipitation demonstrated that RNase-L mRNA associates with a HuR containing complex in intact cells. Activation of endogenous HuR by cell stress, or during myoblast differentiation, increased RNase-L expression, suggesting that RNase-L mRNA is a physiologic target for HuR. HuR-dependent regulation of RNase-L enhanced its antiviral activity demonstrating the functional significance of this regulation. These findings identify a novel mechanism of RNase-L regulation mediated by its 3'-UTR.

AB - RNase-L mediates critical cellular functions including antiviral, pro-apoptotic, and tumor suppressive activities; accordingly, its expression must be tightly regulated. Little is known about the control of RNASEL expression; therefore, we examined the potential regulatory role of a conserved 3'-untranslated region (3'-UTR) in its mRNA. The 3'-UTR mediated a potent decrease in the stability of RNase-L mRNA, and of a chimeric beta-globin-3'-UTR reporter mRNA. AU-rich elements (AREs) are cis-acting regulatory regions that modulate mRNA stability. Eight AREs were identified in the RNase-L 3'-UTR, and deletion analysis identified positive and negative regulatory regions associated with distinct AREs. In particular, AREs 7 and 8 served a strong positive regulatory function. HuR is an ARE-binding protein that stabilizes ARE-containing mRNAs, and a predicted HuR binding site was identified in the region comprising AREs 7 and 8. Co-transfection of HuR and RNase-L enhanced RNase-L expression and mRNA stability in a manner that was dependent on this 3'-UTR region. Immunoprecipitation demonstrated that RNase-L mRNA associates with a HuR containing complex in intact cells. Activation of endogenous HuR by cell stress, or during myoblast differentiation, increased RNase-L expression, suggesting that RNase-L mRNA is a physiologic target for HuR. HuR-dependent regulation of RNase-L enhanced its antiviral activity demonstrating the functional significance of this regulation. These findings identify a novel mechanism of RNase-L regulation mediated by its 3'-UTR.

KW - 3' Untranslated Regions

KW - Antigens, Surface

KW - Antiviral Agents

KW - Apoptosis

KW - Base Sequence

KW - Cell Differentiation

KW - Endoribonucleases

KW - Gene Expression Regulation, Enzymologic

KW - Genes, Reporter

KW - Globins

KW - HeLa Cells

KW - Hu Paraneoplastic Encephalomyelitis Antigens

KW - Humans

KW - Molecular Sequence Data

KW - Myoblasts

KW - RNA, Messenger

KW - RNA-Binding Proteins

U2 - 10.1074/jbc.M607939200

DO - 10.1074/jbc.M607939200

M3 - Journal article

C2 - 17237228

SN - 0021-9258

VL - 282

SP - 7950

EP - 7960

JO - Journal of Biological Chemistry

JF - Journal of Biological Chemistry

IS - 11

ER -