NELF and GAGA factor are linked to promoter-proximal pausing at many genes in Drosophila
NELF and GAGA factor are linked to promoter-proximal pausing at many genes in Drosophila
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DOI：
10.1128/mcb.02224-07
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发表时间：
2008-05-01
影响因子：
5.3
通讯作者：
Gilmour, David S.
中科院分区：
文献类型：
--
作者：
Lee, Chanhyo;Li, Xiaoyong;Gilmour, David S.
最近对RNA聚合酶II（Pol II）的分析表明，Pol II集中在许多活性和非活性基因的启动子上。NELF导致Pol II在果蝇hsp 70基因的启动子近端区域暂停。在这项研究中，全基因组定位分析（染色质免疫沉淀-微阵列芯片[ChIP-chip]分析）显示，NELF集中在果蝇细胞中2，111个基因的5'端。使用Percola基因组足迹来确定暂停的Pol II是否与NELF共定位。发现56个NELF基因中的46个具有Pol II暂停。Pol 11在转录起始位点下游30至50个核苷酸处暂停。在暂停的Pol II附近的DNA序列的分析确定了一个保守的DNA序列，可能与TFIID，但没有检测到RNA二级结构或其他保守序列，可能直接控制延伸的证据。ChIP芯片实验表明，GAGA因子与39%的NELF基因相关。令人惊讶的是，NELF与几乎一半的最高表达基因相关，表明NELF不一定是基因表达的阻遏物。NELF相关的Pol H暂停可能是转录周期中的强制性但有时是短暂的检查点。
Recent analyses of RNA polymerase II (Pol II) revealed that Pol II is concentrated at the promoters of many active and inactive genes. NELF causes Pol II to pause in the promoter-proximal region of the hsp70 gene in Drosophila melanogaster. In this study, genome-wide location analysis (chromatin immunoprecipitation-microarray chip [ChIP-chip] analysis) revealed that NELF is concentrated at the 5' ends of 2,111 genes in Drosophila cells. Permanganate genomic footprinting was used to determine if paused Pol II colocalized with NELF. Forty-six of 56 genes with NELF were found to have paused Pol II. Pol 11 pauses 30 to 50 nucleotides downstream from transcription start sites. Analysis of DNA sequences in the vicinity of paused Pol II identified a conserved DNA sequence that probably associates with TFIID but detected no evidence of RNA secondary structures or other conserved sequences that might directly control elongation. ChIP-chip experiments indicate that GAGA factor associates with 39% of the genes that have NELF. Surprisingly, NELF associates with almost one-half of the most highly expressed genes, indicating that NELF is not necessarily a repressor of gene expression. NELF-associated pausing of Pol H might be an obligatory but sometimes transient checkpoint during the transcription cycle.