The human promyelocytic leukemia zinc finger gene is regulated by the Evi-1 oncoprotein and a novel guanine-rich site binding protein.
PLZF (promyelocytic leukemia zinc finger ) is a transcription factor disrupted in t(11;17)-associated acute promyelocytic leukemia which is highly expressed in undifferentiated myeloid cells. To address the tissue-specific regulation of the promoter, we isolated sequences 1.2-kb 5' to the transcriptional start site. Sequence analysis demonstrated that this region contains one TATA box and several putative transcription factor binding sites including four G/C-rich sites and one Evi-1-like site. A fragment of the promoter spanning 158-bp upstream of the transcription start site displayed relative specificity for PLZF-expressing myeloid cells. Functional promoter assays revealed that an Evi-1-like site at -140/-130 was essential for full promoter activity in every cell line tested while a G-rich site at -15/-7 was important for tissue specificity. Electrophoretic mobility shift assays showed that Evi-1 binds specifically to -140/-130 Evi-1-like site and overexpression of Evi-1 in K562 cells activated the PLZF promoter. UV cross-linking assays showed that the proximal, tissue specific element at -15/-7 bound a novel 28 kDa protein. These results indicate as with other myeloid genes, a relatively small segment of DNA can direct tissue-specific expression, but unlike other myeloid promoters, no critical PU.1 or C/EBP sites were found.
Department of Medicine and Derald H Ruttenberg Cancer Center, The Mount Sinai School of Medicine, New York, NY 10029, USA.
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Takahashi
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Licht
D001483:Base Sequence; D001665:Binding Sites; D004247:DNA / Q000378:metabolism*; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism / Q000502:physiology*; D024202:Electrophoretic Mobility Shift Assay; D020862:GC Rich Sequence / Q000502:physiology*; D017353:Gene Deletion; D015972:Gene Expression Regulation, Neoplastic; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D015473:Leukemia, Promyelocytic, Acute / Q000235:genetics* / Q000378:metabolism; D008156:Luciferases / Q000378:metabolism; D000074008:MDS1 and EVI1 Complex Locus Protein; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D011519:Proto-Oncogenes; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism*; D014158:Transcription, Genetic; D014178:Translocation, Genetic; D014407:Tumor Cells, Cultured; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; D000074008:MDS1 and EVI1 Complex Locus Protein; C063575:MECOM protein, human; D000075722:Promyelocytic Leukemia Zinc Finger Protein; D014157:Transcription Factors; C092037:ZBTB16 protein, human; D004247:DNA; D008156:Luciferases