E2F mediates induction of the Sp1-controlled promoter of the human DNA polymerase epsilon B-subunit gene POLE2.
The B-subunits of replicative DNA polymerases from Archaea to humans belong to the same protein family, suggesting that they share a common fundamental function. We report here the gene structure for the B-subunit of human DNA polymerase epsilon (POLE2), whose expression and transcriptional regulation is typical for replication proteins with some unique features. The 75 bp core promoter region, located within exon 1, contains an Sp1 element that is a critical determinant of promoter activity as shown by the luciferase reporter, electrophoretic mobility shift and DNase I footprinting assays. Two overlapping E2F elements adjacent to the Sp1 element are essential for full promoter activity and serum response. Binding sites for E2F1 and NF-1 reside immediately downstream from the core promoter region. Our results suggest that human POLE2 is regulated by two E2F-pocket protein complexes, one associated with Sp1 and the other with NF-1. So far, only one replicative DNA polymerase B-subunit gene promoter, POLA2 encoding the B-subunit of DNA polymerase alpha, has been characterized. Mitogenic activation of the POLE2 promoter by an E2F-mediated mechanism resembles that of POLA2, but the regulation of basal promoter activity is different between these two genes.
Huang
D
D
Biocenter Oulu and Department of Biochemistry, FIN-90014 University of Oulu, Finland.
Jokela
M
M
Tuusa
J
J
Skog
S
S
Poikonen
K
K
Syväoja
J E
JE
D001483:Base Sequence; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D002455:Cell Division; D016895:Culture Media, Serum-Free; D004247:DNA / Q000235:genetics / Q000378:metabolism; D018983:DNA Footprinting; D004257:DNA Polymerase II / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D003850:Deoxyribonuclease I / Q000378:metabolism; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; D004790:Enzyme Induction; D005091:Exons / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D007438:Introns / Q000235:genetics; D046911:Macromolecular Substances; D008957:Models, Genetic; D008969:Molecular Sequence Data; D009154:Mutation / Q000235:genetics; D051839:NFI Transcription Factors; D023282:Nuclease Protection Assays; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011485:Protein Binding; D012333:RNA, Messenger / Q000032:analysis / Q000235:genetics; D020218:Response Elements / Q000235:genetics*; D056465:Retinoblastoma-Binding Protein 1; D016329:Sp1 Transcription Factor / Q000378:metabolism*; D014157:Transcription Factors / Q000378:metabolism*; D014158:Transcription, Genetic / Q000235:genetics
D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D050684:E2F Transcription Factors; D050687:E2F1 Transcription Factor; C493753:E2F1 protein, human; D046911:Macromolecular Substances; D051839:NFI Transcription Factors; D012333:RNA, Messenger; D056465:Retinoblastoma-Binding Protein 1; D016329:Sp1 Transcription Factor; D014157:Transcription Factors; C080333:transcription factor nuclear factor 1; D004247:DNA; D004257:DNA Polymerase II; D003850:Deoxyribonuclease I