Murata Y, Wharton R P
Howard Hughes Medical Institute, Department of Genetics, Duke University Medical Center, Durham, North Carolina 27710.
Cell. 1995 Mar 10;80(5):747-56. doi: 10.1016/0092-8674(95)90353-4.
Posterior patterning in Drosophila embryos is governed by nanos (nos), which acts by repressing the translation of maternal transcripts of the hunchback (hb) gene. Sites in hb mRNA that mediate this repression, named nanos response elements (NREs), have been identified. However, we know of no evidence of a direct interaction between nos, or any other protein, and the NRE. Here, we show that two proteins present in embryonic extracts, neither one nos, bind specifically to the NRE in vitro. Furthermore, we show that binding in vitro correlates with NRE function in vivo. One of the NRE-binding factors is encoded by pumilio (pum), a gene that, like nos, is essential for abdominal segmentation. These and other observations suggest that pum acts by recognizing the NRE and then recruiting nos. Presumably, the resulting complex inhibits some component of the translation machinery.
果蝇胚胎的后部模式形成由nanos（nos）控制，它通过抑制驼背（hb）基因母体转录本的翻译来发挥作用。已鉴定出hb mRNA中介导这种抑制作用的位点，称为nanos反应元件（NREs）。然而，我们没有发现nos或任何其他蛋白质与NRE之间直接相互作用的证据。在这里，我们表明胚胎提取物中存在的两种蛋白质（都不是nos）在体外特异性结合NRE。此外，我们表明体外结合与体内NRE功能相关。其中一种NRE结合因子由pumilio（pum）编码，该基因与nos一样，对腹部节段化至关重要。这些以及其他观察结果表明，pum通过识别NRE然后招募nos来发挥作用。据推测，由此形成的复合物会抑制翻译机制的某些成分。
