Interleukin-11 mRNA stabilization in phorbol ester-stimulated primate bone marrow stromal cells.
12-O-Tetradecanoylphorbol-13-acetate (TPA) stimulation of PU-34 cells, a primate bone marrow stromal cell line, resulted in a prolonged elevation of interleukin-11 (IL-11) mRNA, which can be inhibited by protein synthesis inhibitors. Nuclear run-on assays and actinomycin D experiments demonstrated that the up-regulation of IL-11 gene expression is mainly controlled at the posttranscriptional level through the protein kinase C (PKC) pathway. Inhibition of PKC activity by calphostin C generated an IL-11 mRNA degradation intermediate in TPA-stimulated PU-34 cells. This intermediate retains the 5' untranslated region (5'UTR) and coding region of the IL-11 mRNA but has lost the poly(A) tail and the 3'UTR. The mechanisms underlying IL-11 mRNA stabilization were further investigated by transfections with a variety of chimeric IL-11 constructs and deletion mutants. Two important observations were made from these transient expression experiments: (i) the same 3'UTR of IL-11 mRNA shown to confer instability in one chimeric transcript may not function as a destabilizer in another chimeric RNA, and (ii) the 5'UTR, coding region, and 3'UTR all contribute to IL-11 mRNA decay, and labile IL-11 deletion transcripts are not necessarily stabilized by TPA stimulation. Our study suggests that multiple regions within the IL-11 mRNA are involved in TPA-stimulated IL-11 mRNA stabilization, possibly through a unique RNA folding conformation involving interactions of various RNA sequences within the IL-11 mRNA molecule.
Yang
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L
Department of Biochemistry and Molecular Biology, Walter Oncology Center, Indiana University School of Medicine, Indianapolis, 46202, USA.
Steussy
C N
CN
Fuhrer
D K
DK
Hamilton
J
J
Yang
Y C
YC
D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D001854:Bone Marrow Cells; D002460:Cell Line; D002467:Cell Nucleus / Q000378:metabolism; D015342:DNA Probes; D003609:Dactinomycin / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects; D019833:Genistein; D017370:Interleukin-11 / Q000096:biosynthesis*; D007529:Isoflavones / Q000494:pharmacology; D007546:Isoquinolines / Q000494:pharmacology; D007700:Kinetics; D008156:Luciferases / Q000096:biosynthesis; D009281:Naphthalenes / Q000494:pharmacology; D016366:Open Reading Frames; D010879:Piperazines / Q000494:pharmacology; D011323:Primates; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D017154:Stromal Cells / Q000276:immunology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D013997:Time Factors; D014158:Transcription, Genetic; D014162:Transfection
D015342:DNA Probes; D004791:Enzyme Inhibitors; D017370:Interleukin-11; D007529:Isoflavones; D007546:Isoquinolines; D009281:Naphthalenes; D010879:Piperazines; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D003609:Dactinomycin; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D019833:Genistein; D008156:Luciferases; D011493:Protein Kinase C; C058819:calphostin C; D013755:Tetradecanoylphorbol Acetate