Transcription factor ZBP-89 regulates the activity of the ornithine decarboxylase promoter
Transcription factor ZBP-89 regulates the activity of the ornithine decarboxylase promoter
复制标题
DOI：
10.1074/jbc.273.32.19955
复制
发表时间：
1998-08-07
影响因子：
4.8
通讯作者：
Morris, DR
中科院分区：
文献类型：
--
作者：
Law, GL;Itoh, H;Morris, DR
适当细胞水平的多胺是细胞生长和分化所必需的。鸟氨酸脱羧酶是多胺生物合成的关键调节酶，需要对该酶的表达进行精确的调控，根据细胞的生长状态，多种有丝分裂原可以提高鸟氨酸脱羧酶的活性，而且在大多数情况下，这种提高是由于mRNA水平的增加。鸟氨酸脱羧酶基因启动子近端的GC盒是基础转录和诱导转录所必需的，SP1和NF-ODC1两种蛋白以互斥的方式与该区域结合。采用酵母单杂交筛选方法，确定DNA结合蛋白ZBP-89是负责NF-ODC1结合活性的候选蛋白。有三条证据证实了这一点：ZBP-89具有NF-ODC1结合活性的共纯化后，ZBP-89抗体特异性地取消了与GC盒的NF-ODC1结合，并且12个不同双链寡核苷酸的结合亲和力在核提取液和体外翻译的ZBP-89之间没有区分；ZBP-89在Schneider果蝇2系中抑制了SPL对鸟氨酸脱羧酶启动子的激活，这与先前认为是NF-ODC1的性质一致。
Appropriate cellular levels of polyamines are required for cell growth and differentiation. Ornithine decarboxylase is a key regulatory enzyme in the biosynthesis of polyamines, and precise regulation of the expression of this enzyme is required, according to cellular growth state, A variety of mitogens increase the level of ornithine decarboxylase activity, and, in most cases, this elevation is due to increased levels of mRNA. A GC box in the proximal promoter of the ornithine decarboxylase gene is required for basal and induced transcriptional activity, and two proteins, Spl and NF-ODC1, bind to this region in a mutually exclusive manner, Using a yeast one-hybrid screening method, ZBP-89, a DNA-binding protein, was identified as a candidate for the protein responsible for NF-ODC1 binding activity. Three lines of evidence verified this identification; ZBP-89 co-purified with NF-ODC1 binding activity, ZBP-89 antibodies specifically abolished NF-ODC1 binding to the GC box, and binding affinities of 12 different double-stranded oligonucleotides were indistinguishable between NF-ODC1, in nuclear extract, and in vitro translated ZBP-89, ZBP-89 inhibited the activation of the ornithine decarboxylase promoter by Spl in Schneider's Drosophila line 2, consistent with properties previously attributed to NF-ODC1.