Altered mRNA binding activity and decreased translational initiation in a nuclear mutant lacking translation of the chloroplast psbA mRNA.
Altered mRNA binding activity and decreased translational initiation in a nuclear mutant lacking translation of the chloroplast psbA mRNA.
复制标题
在缺乏叶绿体 psbA mRNA 翻译的核突变体中，改变了 mRNA 结合活性并减少了翻译起始。
DOI：
10.1128/mcb.16.7.3560
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发表时间：
1996
影响因子：
5.3
通讯作者：
Mayfield,SP
中科院分区：
文献类型：
--
作者：
Yohn,CB;Cohen,A;Danon,A;Mayfield,SP
翻译调控是叶绿体编码基因表达的关键步骤之一。对莱氏衣原体的遗传和生化分析表明，核编码因子与叶绿体mRNA的5′非翻译区特异性相互作用，介导光激活翻译。F35是C. reinhardtii特异性影响psbAmRNA（编码D1，光系统II的核心多肽）的翻译，导致突变株的光合作用缺陷。由于翻译起始减少，F35突变体减少了psbAmRNA的核糖体结合。这种核糖体结合的减少与mRNA稳定性的降低相关。在F35细胞中，psbA特异性蛋白复合物与mRNA 5′非翻译区的结合活性降低，与野生型相比，该结合复合物的两个成员（RB 47和RB 55）降低。这些数据表明，在F35细胞中psbAmRNA结合复合物成员的改变导致psbAmRNA-蛋白质复合物形成的减少，从而导致该mRNA翻译起始的减少。
Translational regulation has been identified as one of the key steps in chloroplast-encoded gene expression. Genetic and biochemical analysis withChlamydomonas reinhardtiihas implicated nucleus-encoded factors that interact specifically with the 5′ untranslated region of chloroplast mRNAs to mediate light-activated translation. F35 is a nuclear mutation inC. reinhardtiithat specifically affects translation of thepsbAmRNA (encoding D1, a core polypeptide of photosystem II), causing a photosynthetic deficiency in the mutant strain. The F35 mutant has reduced ribosome association of thepsbAmRNA as a result of decreased translation initiation. This reduction in ribosome association correlates with a decrease in the stability of the mRNA. Binding activity of thepsbAspecific protein complex to the 5′ untranslated region of the mRNA is diminished in F35 cells, and two members of this binding complex (RB47 and RB55) are reduced compared with the wild type. These data suggest that alteration of members of thepsbAmRNA binding complex in F35 cells results in a reduction inpsbAmRNA-protein complex formation, thereby causing a decrease in translation initiation of this mRNA.