共查询到20条相似文献,搜索用时 31 毫秒
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Soomin Park 《Journal of Plant Biology》2006,49(4):281-285
The evolutionary conserved CCAAT binding protein NF-Y is a common regulatory DNA binding protein consisting of three distinct
subunits. Unlike yeast and mammals, in which only a single copy of each subunit is encoded,Arabidopsis encodes a multi-gene family for each subunit in its genome. Compared with the NF-Y of mammals or yeast, very little is known
about plant NF-Y homologs. HereArabidopsis NF-YA subunits were isolated to determine whether they could form a hete-rotrimeric NF-Y complex with mammalian NF-YB and
NF-YC. This resultant chimeric NF-Y complex had DNA binding ability to the same CCAAT sequences as those of the other life
systems. Therefore, it is possible that plant NF-Y homologs might have biochemical characteristics similar to mammalian NF-Y,
thereby suggesting its functional conservation among organisms. 相似文献
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HAP 转录因子( HAP2/HAP3/HAP4/HAP5) 是存在于酿酒酵母中的一种异源多聚蛋白,它能与酵母中许多启动子上游的CCAAT盒( 顺式作用元件) 专一性结合, 以增强基因的转录。在酵母hap5 突变株的细胞中,用酵母单杂交系统从水稻cDNAGAL4 表达文库中筛选出的阳性克隆是编码谷胱甘肽氧还蛋白的cDNA,提示细胞内的氧化还原系统可能作用于HAP蛋白,从而对CCAAT盒的结合活力起调节作用。对HAP3 亚基分子中半胱氨酸残基的突变实验结果支持上述推测 相似文献
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R Mantovani 《Nucleic acids research》1998,26(5):1135-1143
The CCAAT box is one of the most common elements in eukaryotic promoters, found in the forward or reverse orientation. Among the various DNA binding proteins that interact with this sequence, only NF-Y (CBF, HAP2/3/4/5) has been shown to absolutely require all 5 nt. Analysis of a database with 178 bona fide NF-Y binding sites in 96 unrelated promoters confirms this need and points to specific additional flanking nucleotides (C, Pu, Pu on the 5'-side and C/G, A/G, G,A/C, G on the 3'-side) required for efficient binding. The frequency of CCAAT boxes appears to be relatively higher in TATA-less promoters, particularly in the reverse ATTGG orientation. In TATA-containing promoters the CCAAT box is preferentially located in the -80/-100 region (mean position -89) and is not found nearer to the Start site than -50. In TATA-less promoters it is usually closer to the +1 signal (at -66 on average) and is sometimes present in proximity to the Cap site. The consensus and location of NF-Y binding sites parallel almost perfectly a previous general statistical study on CCAAT boxes in 502 unrelated promoters. This is an indication that NF-Y is the major, if not the sole, CCAAT box recognizing protein and that it might serve different roles in TATA-containing and TATA-less promoters. 相似文献
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We previously reported that the expression of acetylcholinesterase during A23187-induced apoptosis of HeLa cells is regulated by Ca(2+) mobilization through the modulation of mRNA stability and acetylcholinesterase promoter activity. Transactivation of the human acetylcholinesterase promoter by A23187 was partially mediated by the distal CCAAT motif within the -1270 to -1248 fragment of the human acetylcholinesterase promoter, which was bound by the CCAAT binding factor (CBF/NF-Y). In the present study, we investigated the molecular mechanisms by which CBF/NF-Y regulates A23187-induced activation of the human acetylcholinesterase promoter. The results indicate that CBF/NF-Y binding to the distal CCAAT motif suppresses the promoter activity. Electrophoretic mobility shift assays (EMSAs) demonstrated that binding of CBF/NF-Y to the distal CCAAT motif decreased after A23187 treatment. Our results suggest that acetylcholinesterase promoter activation during A23187-induced HeLa cell apoptosis may result partly from the dissociation of CBF/NF-Y from the distal CCAAT motif in the acetylcholinesterase promoter, reversing this suppression. 相似文献
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De novo methylation of MMLV provirus in embryonic stem cells: CpG versus non-CpG methylation 总被引:7,自引:0,他引:7
Nuclear factor Y (NF-Y) is a highly conserved trimeric activator that recognizes with high specificity and affinity the widespread CCAAT box promoter element. We previously cloned the genes of 23 NF-Y genes of Arabidopsis thaliana (Gene 264 (2001) 173). Now that the Arabidopsis genome sequencing project is complete, we present the cloning, alignments and expression profiles of the remaining six genes coding for the three NF-Y subunits. Consistent with our previous reports, most of the new members of the three subunits show a unique tissue-specific pattern, while another AtNF-YC9 is rather ubiquitous. 相似文献