Role of cdc2 kinase phosphorylation and conserved N-terminal proteolysis motifs in cytoplasmic polyadenylation-element-binding protein (CPEB) complex dissociation and degradation.
Role of cdc2 kinase phosphorylation and conserved N-terminal proteolysis motifs in cytoplasmic polyadenylation-element-binding protein (CPEB) complex dissociation and degradation.
复制标题
cdc2 激酶磷酸化和保守的 N 末端蛋白水解基序在细胞质多腺苷酸化元件结合蛋白 (CPEB) 复合物解离和降解中的作用。
作者：
G. Thom;N. Minshall;Anna Git;Joanna Argasinska;N. Standart
胞质多聚腺苷酸化元件结合蛋白（CPEB）是一种在从蠕虫、蝇和蛤到青蛙和小鼠的生物早期发育中的母体mRNA翻译的充分表征和重要调节剂。先前的研究提供的证据表明，蛤和非洲爪蟾CPEB是过度磷酸化在germinal囊泡分解（GVBD）的cdc 2激酶，并降解后不久。为了研究CPEB介导其在减数分裂成熟过程中的修饰的保守特征，我们将编码野生型和突变的蛤CPEB的mRNA显微注射到非洲爪蟾卵母细胞中，随后使其用孕酮成熟。我们观察到：（i）异位表达的蛤CPEB在GVBD处磷酸化，随后降解，反映了内源性非洲爪蟾CPEB蛋白的命运，（ii）9个Ser/Thr Pro定向激酶位点的突变防止磷酸化和降解，以及（iii）PEST盒的缺失，以及推定的细胞周期蛋白破坏盒在较小程度上的缺失，产生了稳定和磷酸化的CPEB版本。我们的结论是，磷酸化的共识和非共识网站的cdc 2激酶的目标蛤CPEB PEST介导的破坏。我们还表明，CPEB的磷酸化介导其从核糖核蛋白复合物的解离，降解之前。我们的研究结果加强了在非洲爪蟾中获得的结果，并对其他无脊椎动物，包括果蝇，秀丽隐杆线虫和Aesthesia，缺乏PEST盒的CPEB有影响。
Cytoplasmic polyadenylation-element-binding protein (CPEB) is a well-characterized and important regulator of translation of maternal mRNA in early development in organisms ranging from worms, flies and clams to frogs and mice. Previous studies provided evidence that clam and Xenopus CPEB are hyperphosphorylated at germinal vesicle breakdown (GVBD) by cdc2 kinase, and degraded shortly after. To examine the conserved features of CPEB that mediate its modification during meiotic maturation, we microinjected mRNA encoding wild-type and mutated clam CPEB into Xenopus oocytes that were subsequently allowed to mature with progesterone. We observed that (i) ectopically expressed clam CPEB is phosphorylated at GVBD and subsequently degraded, mirroring the fate of the endogenous Xenopus CPEB protein, (ii) mutation of nine Ser/Thr Pro-directed kinase sites prevents phosphorylation and degradation and (iii) deletion of the PEST box, and to a lesser extent of the putative cyclin destruction box, generates a stable and phosphorylated version of CPEB. We conclude that phosphorylation of both consensus and non-consensus sites by cdc2 kinase targets clam CPEB for PEST-mediated destruction. We also show that phosphorylation of CPEB mediates its dissociation from ribonucleoprotein complexes, prior to degradation. Our findings reinforce results obtained in Xenopus, and have implications for CPEB from other invertebrates including Drosophila, Caenorhabditis elegans and Aplysia, which lack PEST boxes.
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影响因子：
11.4
作者：
NIELSEN, PJ;TRACHSEL, H
通讯作者：
TRACHSEL, H
影响因子：
11.8
作者：
Tay, J;Richter, JD
通讯作者：
Richter, JD
影响因子：
10.5
作者：
J. Paris;K. Swenson;H. Piwnica-Worms;J. Richter
通讯作者：
J. Paris;K. Swenson;H. Piwnica-Worms;J. Richter
影响因子：
2.7
作者：
Tay, J;Hodgman, R;Richter, JD
通讯作者：
Richter, JD
揭示蛤卵母细胞中的 mRNA：受精时 3UTR 掩蔽元件结合蛋白磷酸化的作用。
DOI：
10.1006/dbio.1996.0024
发表时间：
1996
期刊：
Developmental biology.
影响因子：
--
作者：
Walker,J;Dale,M;Standart,N
通讯作者：
Standart,N