THE DROSOPHILA TRITHORAX PROTEIN BINDS TO SPECIFIC CHROMOSOMAL SITES AND IS CO-LOCALIZED WITH POLYCOMB AT MANY SITES
THE DROSOPHILA TRITHORAX PROTEIN BINDS TO SPECIFIC CHROMOSOMAL SITES AND IS CO-LOCALIZED WITH POLYCOMB AT MANY SITES
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DOI：
10.1002/j.1460-2075.1995.tb07197.x
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发表时间：
1995-05-01
期刊：
影响因子：
11.4
通讯作者：
HARTE, PJ
中科院分区：
文献类型：
--
作者：
CHINWALLA, V;JANE, EP;HARTE, PJ
需要三胸体来稳定地维持在胚胎发生期间通过分割基因的瞬时表达产物的作用而建立的同源异型基因表达模式。三胸大蛋白含有许多高度保守的新的基序，其中一些基序已被假设与其靶基因中的特异性DNA序列直接相互作用。使用针对三胸蛋白的抗体，我们发现它们与幼虫唾液腺多线染色体上的63个特异位点结合，在其已知靶位点检测到三胸结合，双胸和双足复合体，尽管这些位点在唾液腺中处于转录抑制状态，温度敏感的三胸突变大大减少了结合位点的数量，三胸和多梳的同时定位表明它们的许多染色体结合位点重合，我们将一个三胸结合位点定位在Ubx基因大的5'调控区的一部分内，定位到也包含Polycomb组蛋白的结合位点的区间，这些结果表明，三胸通过直接或间接结合其靶基因中的特定DNA序列来发挥其作用。用Polycomb进行的Go定位也表明，这些同源异型基因的激活子和抑制子之间的相互作用可能是其作用模式的一个重要特征。
trithorax is required to stably maintain homeotic gene expression patterns established during embryogenesis by the action of the transiently expressed products of the segmentation genes. The large trithorax proteins contain a number of highly conserved novel motifs, some of which have been hypothesized to interact directly with specific DNA sequences in their target genes, Using antibodies directed against trithorax proteins, we show that they are bound to 63 specific sites on the polytene chromosomes of the larval salivary gland, trithorax binding is detected at the sites of its known targets, the Bithorax and Antennapedia complexes, despite the transcriptionally repressed state of these loci in the salivary gland, A temperature-sensitive trithorax mutation greatly reduces the number of binding sites, Simultaneous localization of trithorax and Polycomb indicates that many of their chromosomal binding sites coincide, We localized one trithorax binding site within a portion of the large 5' regulatory region of the Ubx gene, to an interval which also contains binding sites for Polycomb group proteins, These results suggest that trithorax exerts its effects by binding directly or indirectly to specific DNA sequences in its target genes. Go-localization with Polycomb also suggests that interactions between these activators and repressors of the homeotic genes may be a significant feature of their mode of action.