Vardy Leah, Orr-Weaver Terry L
Whitehead Institute, Massachusetts Institute of Technology, Cambridge, MA 02142, USA.
Dev Cell. 2007 Jan;12(1):157-66. doi: 10.1016/j.devcel.2006.10.017.
The Drosophila PAN GU (PNG) kinase complex regulates the developmental translation of cyclin B. cyclin B mRNA becomes unmasked during oogenesis independent of PNG activity, but PNG is required for translation from egg activation. We find that although polyadenylation of cyclin B augments translation, it is not essential, and a fully elongated poly(A) is not required for translation to proceed. In fact, changes in poly(A) tail length are not sufficient to account for PNG-mediated control of cyclin B translation and of the early embryonic cell cycles. We present evidence that PNG functions instead as an antagonist of PUMILIO-dependent translational repression. Our data argue that changes in poly(A) tail length are not a universal mechanism governing embryonic cell cycles, and that PNG-mediated derepression of translation is an important alternative mechanism in Drosophila.
果蝇的盘古（PNG）激酶复合物调节细胞周期蛋白B的发育性翻译。细胞周期蛋白B信使核糖核酸（mRNA）在卵子发生过程中独立于PNG活性而变得暴露，但从卵子激活开始的翻译则需要PNG。我们发现，虽然细胞周期蛋白B的聚腺苷酸化增强了翻译，但这并非必不可少，并且翻译进行并不需要完全延长的聚腺苷酸（poly(A)）。事实上，聚(A)尾长度的变化不足以解释PNG介导的对细胞周期蛋白B翻译和早期胚胎细胞周期的控制。我们提供的证据表明，PNG反而作为PUMILIO依赖性翻译抑制的拮抗剂发挥作用。我们的数据表明，聚(A)尾长度的变化不是控制胚胎细胞周期的普遍机制，并且PNG介导的翻译去抑制是果蝇中一种重要的替代机制。
