Nitric oxide activation of Erk1/2 regulates the stability and translation of mRNA transcripts containing CU-rich elements.
Nitric oxide (NO*) can stabilize mRNA by activating p38 mitogen-activated protein kinase (MAPK). Here, transcript stabilization by NO* was investigated in human THP-1 cells using microarrays. After LPS pre-stimulation, cells were treated with actinomycin D and then exposed to NO* without or with the p38 MAPK inhibitor SB202190 (SB). The decay of 220 mRNAs was affected; most were stabilized by NO*. Unexpectedly, SB often enhanced rather than antagonized transcript stability. NO* activated p38 MAPK and Erk1/2; SB blocked p38 MAPK, but further activated Erk1/2. RT-PCR confirmed that NO* and SB could additively stabilize certain mRNA transcripts, an effect abolished by Erk1/2 inhibition. In affected genes, these responses were associated with CU-rich elements (CURE) in 3'-untranslated regions (3'-UTR). NO* stabilized the mRNA of a CURE-containing reporter gene, while repressing translation. Dominant-negative Mek1, an Erk1/2 inhibitor, abolished this effect. NO* similarly stabilized, but blocked translation of MAP3K7IP2, a natural CURE-containing gene. NO* increased hnRNP translocation to the cytoplasm and binding to CURE. Over-expression of hnRNP K, like NO*, repressed translation of CURE-containing mRNA. These findings define a sequence-specific mechanism of NO*-triggered gene regulation that stabilizes mRNA, but represses translation.
Wang
Shuibang
S
Critical Care Medicine Department, Clinical Center, National Institutes of Health, Bethesda, MD 20892, USA.
Zhang
Jianhua
J
Theel
Stephanie
S
Barb
Jennifer J
JJ
Munson
Peter J
PJ
Danner
Robert L
RL
D020413:3' Untranslated Regions / Q000737:chemistry*; D002460:Cell Line; D003596:Cytosine / Q000032:analysis; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D034441:Heterogeneous-Nuclear Ribonucleoproteins / Q000378:metabolism; D006801:Humans; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D014176:Protein Biosynthesis; D020871:RNA Stability; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism*; D038621:Regulatory Sequences, Ribonucleic Acid; D014498:Uracil / Q000032:analysis; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
D020413:3' Untranslated Regions; D034441:Heterogeneous-Nuclear Ribonucleoproteins; D012333:RNA, Messenger; D038621:Regulatory Sequences, Ribonucleic Acid; D009569:Nitric Oxide; D014498:Uracil; D003596:Cytosine; D048049:Extracellular Signal-Regulated MAP Kinases; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases