Identification and functional analysis of a CDE/CHR element in the POLD1 promoter.
DNA polymerase delta is encoded by the POLD1 gene, the transcription of which is strictly cell cycle-dependent. However, the means by which POLD1 transcription is regulated by the cell cycle mechanism is currently unknown. We discovered a novel element in the POLD1 promoter known as a CDE(cell cycle-dependent element)/CHR(cell cycle gene homology region) element. A series of luciferase reporter constructs containing various POLD1 promoter mutations were used to investigate the role of the CDE/CHR element in POLD1 transcription. When the CDE/CHR element was mutated, the promoter activity was up-regulated, and the cell-cycle related factors E2F1 and p21 stopped regulating the promoter. Furthermore, cell cycle-dependent changes in the promoter activity required the integrative CDE/CHR element. Electrophoretic mobility shift assay (EMSA) revealed the presence of at least three types of DNA/protein complexes binding to the CDE/CHR element. Our findings provide strong evidence that the CDE/CHR-like sequence is an active functional element in the POLD1 promoter, which is important for the cell cycle regulation of the POLD1 gene.
SONG
NanMeng
N
Key Laboratory of Cell Proliferation and Regulation of Ministry of Education, Beijing Normal University, Beijing 100875, China.
ZHU
XiaoYu
X
SHI
Lei
L
AN
Jing
J
WU
YanWei
Y
SANG
JianLi
J
D001483:Base Sequence; D002453:Cell Cycle / Q000502:physiology; D002460:Cell Line; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004252:DNA Mutational Analysis; D004258:DNA Polymerase III / Q000235:genetics* / Q000378:metabolism; D050687:E2F1 Transcription Factor / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation; D006801:Humans; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D012045:Regulatory Sequences, Nucleic Acid; D016415:Sequence Alignment; D014158:Transcription, Genetic
D050759:Cyclin-Dependent Kinase Inhibitor p21; D050687:E2F1 Transcription Factor; C434055:POLD1 protein, human; D004258:DNA Polymerase III