Differential expression and stability of poly(ADP-ribose)polymerase mRNA in human cells.
The regulation of the expression of the poly(ADP-ribose)polymerase gene was studied in HeLa cells and in quiescent and mitogen-stimulated human lymphocytes by quantitating the mRNA molecules with a new technique based on the polymerase chain reaction. Using plasmid constructs containing defined sequences of the poly(ADP-ribose)polymerase cDNA as internal standards in a competitive PCR reaction, precise measurements of reverse transcribed mRNA copies per microgram of total RNA were obtained. The value found for asynchronously growing HeLa cells (8.6 x 10(5) copies) was very close to that observed for proliferating lymphocytes (8.7 x 10(5)) whereas a 20-fold lower value (0.4 x 10(5)) was obtained for quiescent lymphocytes. The determination of the stability of the mRNA of the enzyme in G0 and stimulated lymphocytes, and in HeLa cells was performed by devising a new PCR amplification system, using non-competitive conditions and plasmid target sequences as internal standards. The half-life of mRNA for poly(ADP-ribose)polymerase was approx. 1 h in G0 lymphocytes and 4-5 h in stimulated lymphocytes and in HeLa cells. This observed difference in stability of the transcripts can partially account for the observed difference in mRNA levels between G0 and stimulated human lymphocytes.
Istituto di Genetica Biochimica ed Evoluzionistica del C.N.R., Pavia, Italy.
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Negroni
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Bertazzoni
D002453:Cell Cycle / Q000235:genetics; D002455:Cell Division / Q000235:genetics; D002478:Cells, Cultured; D015971:Gene Expression Regulation, Enzymologic; D006207:Half-Life; D006367:HeLa Cells; D006801:Humans; D008213:Lymphocyte Activation / Q000235:genetics; D008214:Lymphocytes; D011065:Poly(ADP-ribose) Polymerases / Q000235:genetics*; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000378:metabolism; D016192:Resting Phase, Cell Cycle / Q000235:genetics
D012333:RNA, Messenger; D011065:Poly(ADP-ribose) Polymerases