Isolation and characterization of the human nucleophosmin/B23 (NPM) gene: identification of the YY1 binding site at the 5' enhancer region.
NPM (nucleophosmin/B23) is a major nucleolar protein which is 20 times more abundant in tumor or proliferating cells than in normal resting cells. Recently, it was found that NPM gene is located at the breakpoints of the t(2:5), t(3:5) and t(5:17) chromosome translocation. To understand the human NPM gene's structure and regulation, four genomic clones were isolated from the human chromosome 5 library and their DNA sequences analyzed. The human NPM gene has 12 exons of sizes ranging from 58 to 358 bp. The chromosome breakpoint for t(2:5) and t(5:17) translocation is within intron 4 and the breakpoint for t(3:5) translocation is within intron 6. The initiation site is located 96 bp upstream from the ATG site. A typical TATA box (at -25 nt) and a GC box (at -65 nt) were identified in the promoter region. We identified two gel-shift bands (A and B) with DNA fragment E (-741/-250 nt) by EMSA. A DNA footprint was observed at (-371/-344 nt) with the nuclear extract. A double stranded DNA with the footprint sequence (-371/-344 nt) competed the formation of gel-shift bands A and B in EMSA suggesting that proteins A and B bind to the footprint region. We confirmed that protein A is transcription factor YY1. These results suggest that YY1 may play a role in NPM gene expression. This is the first report on human NPM gene structure and sequence.
Chan
P K
PK
Department of Pharmacology, Baylor College of Medicine, Houston, TX 77030, USA. pchan@bcm.tmc.edu
Chan
F Y
FY
Morris
S W
SW
Xie
Z
Z
D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002874:Chromosome Mapping; D002886:Chromosomes, Human, Pair 17; D002889:Chromosomes, Human, Pair 2; D002895:Chromosomes, Human, Pair 5; D018983:DNA Footprinting; D004268:DNA-Binding Proteins / Q000378:metabolism*; D003850:Deoxyribonuclease I; D050981:Erythroid-Specific DNA-Binding Factors; D005091:Exons; D015698:Genomic Library; D006801:Humans; D007438:Introns; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D000090243:Nucleophosmin; D010750:Phosphoproteins / Q000235:genetics; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000096:biosynthesis; D015183:Restriction Mapping; D017384:Sequence Deletion; D014157:Transcription Factors / Q000378:metabolism*; D014178:Translocation, Genetic; D050986:YY1 Transcription Factor; D016335:Zinc Fingers
D004268:DNA-Binding Proteins; D050981:Erythroid-Specific DNA-Binding Factors; C000716967:NPM1 protein, human; D009687:Nuclear Proteins; D010750:Phosphoproteins; D011993:Recombinant Fusion Proteins; D014157:Transcription Factors; D050986:YY1 Transcription Factor; C494698:YY1 protein, human; C494700:Yy1 protein, rat; D000090243:Nucleophosmin; D003850:Deoxyribonuclease I