Isolation and functional characterization of the human gene encoding the myeloid zinc finger protein MZF-1.
The expression of the human myeloid zinc finger gene (MZF-1) by human bone marrow cells is necessary for granulopoiesis. We have analyzed the structure and function of the MZF-1 gene by diagnostic polymerase chain reaction, genomic cloning, and promoter analysis. Comparison of human promyelocytic HL-60 cell cDNA with isolated MZF-1 genomic clones indicated that the human MZF-1 gene is without introns and spans approximately 3 kb. Restriction enzyme mapping and Southern analysis indicated further that the human MZF-1 gene is a single-copy gene. Primer extension studies identified the major transcription start site as a thymidine residue located 1102 bp upstream of the ATG translation start codon. A putative TATA box sequence (TAAAAA) was found at -66 bp and a CCAAT box at -130 bp relative to the transcription initiation site. In HL-60 cells, MZF-1 mRNA levels are increased by granulopoietic inducers including retinoic acid and GM-CSF. DNA upstream of the transcription start site contains tandem-repeated consensus retinoic acid response elements at -666 through -696 bp and paired putative GM-CSF-responsive sequences centered at -50 and -100 bp. CAT reporter gene constructs containing these DNA regions promoted transcription and conferred transcriptional responsiveness to retinoic acid and GM-CSF when transfected into HL-60 cells. Additional putative regulatory binding sites included conserved MZF-1 zinc finger binding sequences, the importance of which was suggested by the enhanced expression of the endogenous MZF-1 gene following vector-driven expression of MZF-1 constructs in K562 myeloblastic leukemia cells. These findings provide a clearer basis for understanding the role of MZF-1 gene expression in myeloid cell growth and differentiation.
Hui
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Department of Pharmacology and Toxicology, School of Medicine and Biomedical Sciences, State University of New York at Buffalo 14214-3000, USA.
Guo
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X
Bradford
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PG
D001483:Base Sequence; D015139:Blotting, Southern; D001853:Bone Marrow / Q000502:physiology*; D002454:Cell Differentiation; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental; D015723:Gene Library; D018922:HL-60 Cells; D006801:Humans; D051741:Kruppel-Like Transcription Factors; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic; D011994:Recombinant Proteins / Q000096:biosynthesis; D017422:Sequence Analysis, DNA; D014157:Transcription Factors / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic; D014162:Transfection; D016335:Zinc Fingers / Q000235:genetics*
D004268:DNA-Binding Proteins; D051741:Kruppel-Like Transcription Factors; C085969:MZF1 protein, human; D011994:Recombinant Proteins; D014157:Transcription Factors