Phosphorylation of CPEB by Eg2 mediates the recruitment of CPSF into an active cytoplasmic polyadenylation complex
Phosphorylation of CPEB by Eg2 mediates the recruitment of CPSF into an active cytoplasmic polyadenylation complex
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DOI：
10.1016/s1097-2765(00)00121-0
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发表时间：
2000-11-01
期刊：
影响因子：
16
通讯作者：
Richter, JD
中科院分区：
文献类型：
--
作者：
Mendez, R;Murthy, KGK;Richter, JD
非洲爪蟾卵母细胞从前期I逮捕的释放在很大程度上是由休眠的母体mRNA的细胞质聚腺苷酸化诱导的翻译驱动的。两个顺式元件，CPE和六核苷酸AAUAAA，以及它们各自的结合因子，CPEB和CPSF的细胞质形式，控制聚腺苷酸化。聚腺苷酸化的最接近的刺激是Eg 2催化的CPEB丝氨酸174磷酸化。在这里，我们表明，这种磷酸化事件刺激CPEB和CPSF之间的相互作用。这种相互作用是直接的，不需要RNA束缚，并通过CPSF的160 kDa亚基发生。Eg 2刺激和CPE依赖的多聚腺苷酸化在体外重建使用纯化的成分。这些结果表明，Eg 2-磷酸化的CPEB的分子功能是招募CPSF到一个活跃的细胞质聚腺苷酸化复合物。
The release of Xenopus oocytes from prophase I arrest is largely driven by the cytoplasmic polyadenylation-induced translation of dormant maternal mRNAs. Two cis elements, the CPE and the hexanucleotide AAUAAA, and their respective binding factors, CPEB and a cytoplasmic form of CPSF, control polyadenylation. The most proximal stimulus for polyadenylation is Eg2-catalyzed phosphorylation of CPEB serine 174. Here, we show that this phosphorylation event stimulates an interaction between CPEB and CPSF. This interaction is direct, does not require RNA tethering, and occurs through the 160 kDa subunit of CPSF. Eg2-stimulated and CPE-dependent polyadenylation is reconstituted in vitro using purified components. These results demonstrate that the molecular function of Eg2-phosphorylated CPEB is to recruit CPSF into an active cytoplasmic polyadenylation complex.