Defining a novel cis-element in the 3'-untranslated region of mammalian ribonucleotide reductase component R2 mRNA. cis-trans-interactions and message stability.
Mammalian ribonucleotide reductase is a highly regulated activity essential for DNA synthesis and repair. The 3'-untranslated region (3'-UTR) of mammalian ribonucleotide reductase R2 mRNA has been implicated in the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate-mediated stabilization of mouse BALB/c 3T3 R2 message. We investigated the possibility that the 3'-UTR contains regulatory information for R2 mRNA turnover. Using 3'-end-labeled RNA in gel shift and UV cross-linking analyses, we detected in the 3'-UTR a novel 9-nucleotide cis-element, 5'-UCGUGUGCU-3', which interacted with a widely distributed cellular cytosolic protease-sensitive factor(s) in a sequence-specific manner to form a 45-kDa R2 binding protein complex. The binding activity was redox-sensitive and down-regulated by 12-O-tetradecanoylphorbol-13-acetate and okadaic acid in a dose-dependent manner. Insertion of a 154-base pair fragment containing the cis-element led to markedly reduced accumulation of chloramphenicol acetyltransferase hybrid mRNA relative to the same insert carrying a series of G --> A mutations within this element that eliminated binding. We suggest that the 9-nucleotide region functions as a destabilizing element. These results provide a model for ribonucleotide reductase gene expression through a novel and specific mRNA cis-trans-interaction involving a phosphorylation signal pathway that leads to changes in the stability of R2 message.
Amara
F M
FM
Manitoba Institute of Cell Biology, University of Manitoba, Winnipeg, Manitoba, R3E 0V9, Canada.
Sun
J
J
Wright
J A
JA
D016475:3T3 Cells; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D017931:DNA Primers / Q000737:chemistry; D015971:Gene Expression Regulation, Enzymologic; D005796:Genes; D006801:Humans; D006860:Hydrogen Bonding; D051379:Mice; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D010084:Oxidation-Reduction; D010750:Phosphoproteins / Q000378:metabolism; D011485:Protein Binding; D012333:RNA, Messenger / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D012264:Ribonucleotide Reductases / Q000235:genetics*
D017931:DNA Primers; D010750:Phosphoproteins; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D012264:Ribonucleotide Reductases