CPEB3 and CPEB4 in neurons: analysis of RNA-binding specificity and translational control of AMPA receptor GluR2 mRNA
CPEB3 and CPEB4 in neurons: analysis of RNA-binding specificity and translational control of AMPA receptor GluR2 mRNA
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DOI：
10.1038/sj.emboj.7601322
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发表时间：
2006-10-18
期刊：
影响因子：
11.4
通讯作者：
Richter, Joel D.
中科院分区：
文献类型：
--
作者：
Huang, Yi-Shuian;Kan, Ming-Chung;Richter, Joel D.
CPEB是一种序列特异性的RNA结合蛋白，能促进多聚腺苷诱导的卵母细胞和神经元中的翻译。脊椎动物包含另外三个编码CPEB样蛋白的基因，所有这些基因都在大脑中表达。在这里，我们使用SELEX、RNA结构探测和RNA足迹来表明CPEB和CPEB样蛋白与不同的RNA序列相互作用，从而构成不同类别的RNA结合蛋白。在转基因神经元中，CPEB3在系留功能分析中抑制报告RNA的翻译；作为对NMDA受体激活的反应，翻译被刺激。与CPEB不同的是，CPEB3介导的翻译不太可能涉及细胞质内的聚腺苷酸化，因为它既不需要顺式作用的AAUAAA，也不需要反式作用的切割和聚腺苷酸化特异性因子，而这两者都是CPEB诱导的聚腺苷酸化所必需的。CPEB3介导的翻译的一个靶点是GluR2 mRNA；CPEB3不仅在体外和体内结合这种RNA，而且在神经元中CPEB3的RNAi敲除导致GluR2蛋白水平升高。这些结果表明，CPEB3是一种序列特异性的翻译调节蛋白。
CPEB is a sequence-specific RNA-binding protein that promotes polyadenylation-induced translation in oocytes and neurons. Vertebrates contain three additional genes that encode CPEB-like proteins, all of which are expressed in the brain. Here, we use SELEX, RNA structure probing, and RNA footprinting to show that CPEB and the CPEB-like proteins interact with different RNA sequences and thus constitute different classes of RNA-binding proteins. In transfected neurons, CPEB3 represses the translation of a reporter RNA in tethered function assays; in response to NMDA receptor activation, translation is stimulated. In contrast to CPEB, CPEB3-mediated translation is unlikely to involve cytoplasmic polyadenylation, as it requires neither the cis-acting AAUAAA nor the trans-acting cleavage and polyadenylation specificity factor, both of which are necessary for CPEB-induced polyadenylation. One target of CPEB3-mediated translation is GluR2 mRNA; not only does CPEB3 bind this RNA in vitro and in vivo, but an RNAi knockdown of CPEB3 in neurons results in elevated levels of GluR2 protein. These results indicate that CPEB3 is a sequence-specific translational regulatory protein.