Transcriptional regulation of the human DNA methyltransferase 3A and 3B genes by Sp3 and Sp1 zinc finger proteins.
The DNMT3A (DNA methyltransferase 3A) and DNMT3B genes encode putative de novo methyltransferases and show complex transcriptional regulation in the presence of three and two different promoters respectively. All promoters of DNMT3A and DNMT3B lack typical TATA sequences adjacent to their transcription start sites and contain several Sp1-binding sites. The importance of these Sp1-binding sites was demonstrated by using a GC-rich DNA-binding protein inhibitor, mithramycin A, i.e. on the basis of decrease in the promoter activities and mRNA expression levels of DNMT3A and DNMT3B. Overexpression of Sp1 and Sp3 up-regulated the promoter activities of these two genes. The physical binding of Sp1 and Sp3 to DNMT3A and DNMT3B promoters was confirmed by a gel shift assay. Interestingly, Sp3 overexpression in HEK-293T cells (human embryonic kidney 293T cells) resulted in 3.3- and 4.0-fold increase in DNMT3A and DNMT3B mRNA expression levels respectively by quantitative reverse transcriptase-PCR, whereas Sp1 overexpression did not. Furthermore, an antisense oligonucleotide to Sp3 significantly decreased the mRNA levels of DNMT3A and DNMT3B. These results indicate the functional importance of Sp proteins, particularly Sp3, in the regulation of DNMT3A and DNMT3B gene expression.
Jinawath
Artit
A
Department of Molecular Oncology, Graduate School of Medicine and Dentistry, Tokyo Medical and Dental University, 1-5-45, Yushima, Bunkyo-ku, Tokyo 113-8519, Japan.
Miyake
Satoshi
S
Yanagisawa
Yuka
Y
Akiyama
Yoshimitsu
Y
Yuasa
Yasuhito
Y
D000256:Adenoviridae; D001665:Binding Sites / Q000235:genetics; D002460:Cell Line; D002461:Cell Line, Transformed; D004247:DNA / Q000378:metabolism; D004248:DNA (Cytosine-5-)-Methyltransferases / Q000037:antagonists & inhibitors / Q000235:genetics*; D000090205:DNA Methyltransferase 3A; D004268:DNA-Binding Proteins / Q000172:deficiency / Q000378:metabolism / Q000502:physiology*; D015971:Gene Expression Regulation, Enzymologic / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007668:Kidney / Q000737:chemistry / Q000196:embryology / Q000378:metabolism / Q000821:virology; D016297:Mutagenesis, Site-Directed / Q000235:genetics; D016376:Oligonucleotides, Antisense / Q000235:genetics / Q000494:pharmacology; D008926:Plicamycin / Q000031:analogs & derivatives* / Q000494:pharmacology; D011401:Promoter Regions, Genetic / Q000187:drug effects / Q000235:genetics; D012333:RNA, Messenger / Q000037:antagonists & inhibitors / Q000096:biosynthesis / Q000378:metabolism; D016329:Sp1 Transcription Factor / Q000378:metabolism / Q000502:physiology*; D051705:Sp3 Transcription Factor; D014157:Transcription Factors / Q000172:deficiency / Q000378:metabolism / Q000502:physiology*; D014158:Transcription, Genetic / Q000187:drug effects / Q000235:genetics*; D016335:Zinc Fingers / Q000235:genetics*; D000097584:DNA Methyltransferase 3B
D004247:DNA; D004248:DNA (Cytosine-5-)-Methyltransferases; D000090205:DNA Methyltransferase 3A; D004268:DNA-Binding Proteins; D016376:Oligonucleotides, Antisense; D008926:Plicamycin; D012333:RNA, Messenger; D016329:Sp1 Transcription Factor; D051705:Sp3 Transcription Factor; D014157:Transcription Factors; D000097584:DNA Methyltransferase 3B; C000717967:DNMT3A protein, human; C497121:SP3 protein, human; C066851:mithramycin A