ATF is important to late S phase-dependent regulation of DNA topoisomerase IIalpha gene expression in HeLa cells.
DNA topoisomerase IIalpha (Topo IIalpha) is regulated in late S phase-dependent manner. To identify late S phase-dependent cis-acting elements of Topo IIalpha gene, we have investigated the synchronized HeLa cells with chloramphenicol acetyltransferase and DNase I footprinting assays. The level of Topo IIalpha mRNA increased after release from aphidicolin block and reached a maximum in 8h (late S phase) in HeLa cells, and Topo II unknotting activity was also in parallel with the level of Topo IIalpha mRNA. The late S phase-regulatory element was found to be located in the region containing ATF-binding element between -290 and -90bp and the region was required for a maximal stimulation during late S phase. DNase I footprinting assay showed that ATF-binding element and novel cis-acting element (Topo IIalpha-specific sequence) were the principal protein-binding sites and the proteins interacting with these elements were induced during late S phase. One DNA-protein complex was formed by DNA mobility shift assay when ATF-binding site was incubated with nuclear extract prepared from late S phase cells, but no protein bound in non-S phase cells. Taken together, these results suggest that ATF may be essential transacting factor for maximal expression of Topo IIalpha gene during late S phase in HeLa cells.
Son
Mee-Young
MY
Department of Biochemistry, Chungnam National University, Moonhwa-dong, Jungu, Daejeon 301-747, South Korea.
Kim
Tae-Jeong
TJ
Kweon
Kwang-In
KI
Park
Jong-Il
JI
Park
Chung
C
Lee
Young-Chul
YC
No
Zaesung
Z
Ahn
Jong-Woong
JW
Yoon
Wan-Hee
WH
Park
Seung-Kiel
SK
Lim
Kyu
K
Hwang
Byung-Doo
BD
D051696:Activating Transcription Factors; D000951:Antigens, Neoplasm; D001483:Base Sequence; D001798:Blood Proteins / Q000235:genetics / Q000378:metabolism*; D015152:Blotting, Northern; D002453:Cell Cycle / Q000235:genetics; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D018983:DNA Footprinting; D004250:DNA Topoisomerases, Type II / Q000235:genetics* / Q000378:metabolism; D004268:DNA-Binding Proteins; D003850:Deoxyribonuclease I / Q000378:metabolism; D024202:Electrophoretic Mobility Shift Assay; D015971:Gene Expression Regulation, Enzymologic; D005809:Genes, Regulator / Q000235:genetics; D006367:HeLa Cells / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009363:Neoplasm Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger; D016196:S Phase / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D015533:Transcriptional Activation
D051696:Activating Transcription Factors; D000951:Antigens, Neoplasm; D001798:Blood Proteins; D004268:DNA-Binding Proteins; D009363:Neoplasm Proteins; D012333:RNA, Messenger; D014157:Transcription Factors; D015500:Chloramphenicol O-Acetyltransferase; D003850:Deoxyribonuclease I; D004250:DNA Topoisomerases, Type II