A cryptopromoter is activated in the proliferating cell nuclear antigen gene of growth arrested cells.
We have examined the regulation of the proliferating cell nuclear antigen gene (PCNA) in a hamster fibroblast cell line (tk-ts13) which is temperature sensitive for growth. These tk-ts13 cells, at the restrictive temperature, are growth arrested in the G1 phase of the cell cycle. The cells were stably transfected with a full length human PCNA gene, and the resulting cell lines (K525 cells) were analyzed. We find that, in growth arrested K525 cells, a cryptopromoter is activated in the transfected human PCNA gene. The cryptopromoter resides in intron 4 which is necessary for proper regulation of the PCNA gene. Removal of this intron leads to increased expression of PCNA in cells which have entered the G0 state. An Alu sequence residing in intron 4 is implicated as the promoter element which is active during growth arrest.
Department of Microbiology and Immunology, Jefferson Cancer Institute, Philadelphia, Pennsylvania.
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C
Sell
C D
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Chang
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Koniecki
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HM
Chen
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Baserga
D000818:Animals; D001483:Base Sequence; D015152:Blotting, Northern; D002453:Cell Cycle / Q000502:physiology; D002478:Cells, Cultured; D006224:Cricetinae; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D006207:Half-Life; D006801:Humans; D007438:Introns / Q000502:physiology; D008647:Mesocricetus; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D016133:Polymerase Chain Reaction; D018809:Proliferating Cell Nuclear Antigen; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016192:Resting Phase, Cell Cycle / Q000502:physiology; D012260:Ribonucleases; D013696:Temperature; D014158:Transcription, Genetic; D014162:Transfection
D009687:Nuclear Proteins; D018809:Proliferating Cell Nuclear Antigen; D012260:Ribonucleases