5'-UPSTREAM SEQUENCES OF MYD88, AN IL-6 PRIMARY RESPONSE GENE IN M1 CELLS - DETECTION OF FUNCTIONAL IRF-1 AND STAT FACTORS BINDING-SITES
5'-UPSTREAM SEQUENCES OF MYD88, AN IL-6 PRIMARY RESPONSE GENE IN M1 CELLS - DETECTION OF FUNCTIONAL IRF-1 AND STAT FACTORS BINDING-SITES
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DOI：
10.1093/nar/23.17.3539
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发表时间：
1995-09-11
影响因子：
14.9
通讯作者：
CHEBATH, J
中科院分区：
文献类型：
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作者：
HARROCH, S;GOTHELF, Y;CHEBATH, J
已对白细胞介素 6 (Il-6) 初级反应基因 MyD88 的上游序列中的转录调控元件进行了分析，MyD88 2.3 kb mRNA 在用 Il-6 分化骨髓白血病 M1 细胞的过程中被强烈且持续地诱导。在小鼠基因组DNA的12kb区域中发现了MyD88 cDNA序列，使用Il-6处理的M1细胞RNA，已经定位了两个转录起始位点，类似于克隆的cDNA的5'末端上游100bp，我们对包括第一个外显子在内的1.4kb 5'基因组DNA进行了测序，在mRNA转录起始位点的5'中，MyD88核苷酸序列与5'互补序列有85%相同大鼠 3'-酮乙酰 CoA 硫解酶基因的序列，超过 1.2 kb，是赋予报告基因 IL-6 诱导转录的 DNA 元件，位于 MyD88 第一个 RNA 起始位点上游 30 bp，包含细胞因子激活转录因子 Stat 以及干扰素调节因子-1 和 -2（IRF-1 和 IRF-2）的重叠结合位点。体外结合测定表明，在 Il-6 处理早期，Stat 因子与该元件的连接需要酪氨酸激酶激活，转录激活剂 IRF1 在后期也被诱导与该序列结合。提出了通过这两类因子持续激活 MyD88 基因的模型。
Transcription regulatory elements have been analyzed in upstream sequences of an Interleukin-6 (Il-6) primary response gene, MyD88, MyD88 2.3 kb mRNA is strongly and persistently induced in the course of myeloleukemic M1 cells differentiation with Il-6. MyD88 cDNA sequences were found in a region of 12 kb of mouse genomic DNA, Using Il-6 treated M1 cell RNAs, two transcription start sites have been localized, similar to 100 bp upstream from the 5' end of the cloned cDNA, We sequenced 1.4 kb of 5' genomic DNA including the first exon, In 5' of mRNA transcription start site, MyD88 nucleotidic sequence is 85% identical to 5' complementary sequences of the rat 3'-ketoacetyl CoA thiolase gene, over 1.2 kb, A DNA element conferring Il-6-inducible transcription to reporter genes, and localized 30 bp upstream of MyD88 first RNA start site, contains overlapping binding sites for cytokine activated transcription factors Stat and for the Interferon Regulatory Factor-1 and -2 (IRF-1 and IRF-2). In vitro binding assays showed that attachment of Stat factors to this element early in Il-6 treatment requires tyrosine kinase activation, IRF1, an activator of transcription, is also induced to bind to this sequence at later times, A model of persistent activation of MyD88 gene through these two types of factors is proposed.