Protein kinase A-regulated instability site in the 3'-untranslated region of lactate dehydrogenase-A subunit mRNA.
Expression of the lactate dehydrogenase A subunit (LDH-A) gene can be controlled by transcriptional as well as posttranscriptional mechanisms. In rat C6 glioma cells, LDH-A mRNA is stabilized by activation and synergistic interaction of protein kinases A and C. In the present study, we aimed to identify the sequence domain which determines and regulates mRNA stability/instability by protein kinase A and focused our attention on the 3'-untranslated region (3'-UTR) of LDH-A mRNA. We have constructed various chimeric globin/lactate dehydrogenase (ldh) genes linked to the c-fos promoter and stably transfected them into rat C6 glioma cells. After their transfection, we determined the half-life of transcribed chimeric globin/ldh mRNAs. The results showed that at least three sequence domains within the LDH-A 3'-UTR consisting of nucleotides 1286-1351, 1453-1471, and 1471-1502 are responsible for the relatively rapid rate of LDH-A mRNA turnover in the cytoplasm. Whereas chimeric globin/ldh mRNAs containing the base sequences 1286-1351 and 1453-1471 were not stabilized by (Sp)-cAMPS, an activator of protein kinase A, instability caused by the 1471-1502 domain was significantly reversed. Additional deletion and mutational analyses demonstrated that the 3'-UTR fragment consisting of the 22 bases 1478-1499 is a critical determinant for the (Sp)-cAMPS-mediated LDH-A mRNA stabilizing activity. Because of its functional characteristics, we named the 22-base region "cAMP-stabilizing region."
Tian
D
D
Department of Cellular and Molecular Biology and Cancer Center, Northwestern University Medical School, Chicago, Illinois 60611-3008, USA.
Huang
D
D
Short
S
S
Short
M L
ML
Jungmann
R A
RA
D000818:Animals; D001483:Base Sequence; D000242:Cyclic AMP / Q000031:analogs & derivatives / Q000494:pharmacology; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015971:Gene Expression Regulation, Enzymologic; D016762:Genes, fos; D005910:Glioma; D005914:Globins / Q000096:biosynthesis / Q000235:genetics; D007527:Isoenzymes; D007700:Kinetics; D007770:L-Lactate Dehydrogenase / Q000096:biosynthesis / Q000235:genetics*; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D013873:Thionucleotides / Q000494:pharmacology; D014158:Transcription, Genetic; D014162:Transfection; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D007527:Isoenzymes; D046911:Macromolecular Substances; D009838:Oligodeoxyribonucleotides; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins; D013873:Thionucleotides; C016957:adenosine-3',5'-cyclic phosphorothioate; D005914:Globins; D000242:Cyclic AMP; D007770:L-Lactate Dehydrogenase; D017868:Cyclic AMP-Dependent Protein Kinases