The Drosophila Bruno paralogue Bru-3 specifically binds the EDEN translational repression element
The Drosophila Bruno paralogue Bru-3 specifically binds the EDEN translational repression element
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DOI：
10.1093/nar/gkh627
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发表时间：
2004-06-01
影响因子：
14.9
通讯作者：
Aït-Ahmed, O
中科院分区：
文献类型：
--
作者：
Delaunay, J;Mée, GL;Aït-Ahmed, O
我们在以前的工作中报告说，依赖伊甸园的母体mRNAs的翻译抑制在果蝇和非洲爪哇之间是保守的。在非洲爪哇，这种抑制是通过伊甸园与布鲁诺类因子伊甸园BP的结合实现的。我们在目前的工作中表明，果蝇Bruno蛋白，45 kDa的Bru-3蛋白(P45)，特异性地与伊甸园元素结合，并作为同源二聚体。我们首次描述了一个以前没有检测到的67个氨基酸的结构域，在发散的连接子区域，LSM结构域(LSM代表连接子特定的基序)。我们认为，该结构域在包括Bru-3、Eden-BP和CUG-BP在内的Bruno样蛋白的子集中的存在，而不是Bruno或其其他类似物Bru-2中的存在，可能与特异性RNA识别有关。有趣的是，使用线程和分子建模的比较结构分析表明，新的结构域可能与果蝇性别致死蛋白(SXL)的第一个RNA识别基序有较远的关系。系统发育分析和基于其与Eden元件特异性结合的实验数据支持Bru-3是Eden-BP/CUG-BP同源基因的结论。
We reported in our previous work that the EDEN-dependent translational repression of maternal mRNAs was conserved between Drosophila and Xenopus. In Xenopus, this repression is achieved through the binding of EDEN to the Bruno-like factor, EDEN-BP. We show in the present work that the Drosophila Bruno paralogue, the 45 kDa Bru-3 protein (p45), binds specifically to the EDEN element and acts as a homodimer. We describe for the first time a previously undetected 67 amino acid domain, found in the divergent linker region, the lsm domain (lsm stands for linker-specific motif). We propose that the presence of this domain in a subset of the Bruno-like proteins, including Bru-3, EDEN-BP and CUG-BP but not Bruno nor its other paralogue Bru-2, might be responsible for specific RNA recognition. Interestingly, comparative structural analyses using threaders and molecular modelling suggest that the new domain might be distantly related to the first RNA recognition motif of the Drosophila sex-lethal protein (sxl). The phylogenetic analyses and the experimental data based on its specific binding to the EDEN element support the conclusion that Bru-3 is an EDEN-BP/CUG-BP orthologue.