The role of the promoter in the expression of the PCNA gene.
G1-specific temperature-sensitive (ts) mutants of the cell cycle arrest in G1 after serum stimulation at the restrictive temperature. Under these conditions, the RNA levels of late growth-regulated genes (such as DNA polymerase alpha, PCNA, thymidine kinase, and core histones) are markedly decreased or even undetectable, while early growth-regulated genes (for instance, c-myc) are normally expressed, and certain promoters are actually super-induced. We have used the human PCNA gene transfected into TK-ts13 cells (a G1-specific ts mutant) to investigate whether the inhibition of gene expression caused by this type of growth inhibition occurs at a transcriptional or post-transcriptional level. Constructs were made in which the 5' and 3' flanking sequences of the human PCNA gene were replaced by the corresponding elements of the SV40 T antigen coding gene. Using these constructs and data from run-on assays and RT-PCR, we conclude that the failure of expression of the PCNA gene in G1-arrested TK-ts13 cells occurs at the transcriptional level.
Jefferson Cancer Institute, Thomas Jefferson University, Philadelphia, Pennsylvania 19107-5541.
R H
RH
Charollais
H
H
Alder
A
A
Ferber
J
J
Koniecki
C
C
Sell
R
R
Baserga
D000818:Animals; D002453:Cell Cycle; D002460:Cell Line; D006224:Cricetinae; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase / Q000378:metabolism; D005347:Fibroblasts; D015870:Gene Expression; D005813:Genes, Synthetic; D006801:Humans; D008647:Mesocricetus; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics; D018809:Proliferating Cell Nuclear Antigen; D011401:Promoter Regions, Genetic; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis* / Q000235:genetics; D012045:Regulatory Sequences, Nucleic Acid; D013539:Simian virus 40 / Q000235:genetics*; D013696:Temperature; D014158:Transcription, Genetic
D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D011993:Recombinant Fusion Proteins; D004258:DNA Polymerase III; D004259:DNA-Directed DNA Polymerase