Unmasking mRNA in clam oocytes: role of phosphorylation of a 3' UTR masking element-binding protein at fertilization.
Unmasking mRNA in clam oocytes: role of phosphorylation of a 3' UTR masking element-binding protein at fertilization.
复制标题
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
复制
发表时间：
1996
期刊：
影响因子：
--
通讯作者：
Standart,N
中科院分区：
文献类型：
--
作者：
Walker,J;Dale,M;Standart,N
在减数分裂成熟期间或无脊椎动物和脊椎动物卵母细胞受精后，许多静态储存的 mRNA 被募集到多核糖体中。在蛤蜊（Spisula Solidissima）中，这种隐藏的信息包括编码细胞周期蛋白A和核糖核苷酸还原酶小亚基的丰富mRNA。我们之前已经表明，通过在其同源 3' 非翻译区域中添加对应于相当短（130-140 个核苷酸）片段的反义 RNA，可以在体外卵母细胞无细胞提取物中实现对这两个信息的 mRNA 特异性揭示。我们假设反义 RNA 阻止了掩蔽阻遏蛋白的结合 (Standartet al.,1990)。在这里，我们报告了 UV 交联和凝胶延迟研究，这些研究表明翻译调节 mRNA 的掩蔽部分结合了 82 kDa (p82) 的卵母细胞蛋白，该蛋白在受精后被磷酸化。这种修饰伴随着凝胶阻滞测定中 RNP 复合物形成的改变。这些变化可能反映了掩蔽 mRNA 翻译的激活。 p82 磷酸化在母体 mRNA 暴露中的作用是在一种由蛤卵母细胞开发的新型体外激活系统中进行评估的，该系统基于受精时 pH 值的自然升高。随着 mRNA 的揭开，包括 cdc2 和 MAP 激酶在内的多种激酶以及 p82 磷酸化在该系统中被激活。丝氨酸/苏氨酸激酶抑制剂（包括 6-DMAP、星形孢菌素和 H7）抑制 p82 磷酸化，而酪氨酸激酶、蛋白激酶 C、cAMP 依赖性蛋白激酶和 p70s6k 抑制剂则不能阻止这种修饰。 cdc2 激酶的特异性抑制剂 p27Kip1 可阻止 p82 磷酸化和翻译激活，强烈表明 p82 修饰是揭开掩蔽所必需的。
During meiotic maturation or after fertilization of invertebrate and vertebrate oocytes, many of the quiescent stored mRNAs are recruited into polysomes. In the clam,Spisula solidissima,such masked messages include the abundant mRNAs encoding cyclin A and the small subunit of ribonucleotide reductase. We have previously shown that mRNA-specific unmasking of these two messages can be achievedin vitro,in oocyte cell-free extracts, by the addition of antisense RNAs corresponding to a fairly short (130–140 nucleotides) segment in their cognate 3′ untranslated regions. We postulated that the antisense RNAs prevented the binding of a masking repressor protein (Standartet al.,1990). Here we report UV-crosslinking and gel retardation studies which show that the masking portions of the translationally regulated mRNAs bind an oocyte protein of 82 kDa (p82), which is phosphorylated after fertilization. This modification was accompanied by altered RNP complex formation in gel retardation assays. These changes presumably reflect the activation of translation of the masked mRNAs. The role of p82 phosphorylation in maternal mRNA unmasking was assessed in a novelin vitroactivation system developed from clam oocytes, based upon the natural rise in pH which accompanies fertilization. Concomitant with mRNA unmasking, several kinases, including cdc2 and MAP kinases were activated in this system, as was p82 phosphorylation. Inhibitors of serine/threonine kinases, including 6-DMAP, staurosporine, and H7 inhibited p82 phosphorylation, whereas inhibitors of tyrosine kinases, protein kinase C, cAMP-dependent protein kinase, and p70s6kdid not prevent this modification. A specific inhibitor of cdc2 kinase, p27Kip1, prevented p82 phosphorylation and translational activation, strongly suggesting that p82 modification is required for unmasking.
早期胚胎细胞周期的控制。
DOI：
--
发表时间：
1991
期刊：
Cold Spring Harbor Symposia on Quantitative Biology
影响因子：
--
作者：
J. Ruderman;J. Westendorf;F. Luca;David Beach;Giulio Draetta;K. Swenson;E. H. Davidson;J. V. Ruderman;J. Posakony
通讯作者：
J. Posakony
MAP 激酶和静止细胞的激活。
影响因子：
7.5
作者：
J. Ruderman
通讯作者：
J. Ruderman