Institute of Molecular Biotechnology of the Austrian Academy of Sciences (IMBA), Vienna, Austria.
EMBO J. 2011 Aug 23;30(19):3977-93. doi: 10.1038/emboj.2011.308.
PIWI proteins and their bound PIWI-interacting RNAs (piRNAs) form the core of a gonad-specific small RNA silencing pathway that protects the animal genome against the deleterious activity of transposable elements. Recent studies linked the piRNA pathway to TUDOR biology as TUDOR domains of various proteins bind symmetrically methylated Arginine residues in PIWI proteins. We systematically analysed the Drosophila TUDOR protein family and identified four previously not characterized TUDOR domain-containing proteins (CG4771, CG14303, CG11133 and CG31755) as essential piRNA pathway factors. We characterized CG4771 (Vreteno) in detail and demonstrate a critical role for this protein in primary piRNA biogenesis. Vreteno physically and/or genetically interacts with the primary pathway components Piwi, Armitage, Yb and Zucchini. Vreteno also interacts with the Tdrd12 orthologues CG11133 (Brother of Yb) and CG31755 (Sister of Yb), which are essential for the primary piRNA pathway in the germline and probably replace the function of the related but soma-specific factor Yb.
PIWI 蛋白及其结合的 PIWI 相互作用 RNA（piRNA）构成了一个性腺特异性小 RNA 沉默途径的核心，该途径保护动物基因组免受转座元件的有害活性的影响。最近的研究将 piRNA 途径与 Tudor 生物学联系起来，因为各种蛋白质的 Tudor 结构域结合 PIWI 蛋白中对称甲基化的精氨酸残基。我们系统地分析了果蝇的 Tudor 蛋白家族，并鉴定了四个以前未被描述的含有 Tudor 结构域的蛋白质（CG4771、CG14303、CG11133 和 CG31755）作为必需的 piRNA 途径因子。我们详细地对 CG4771（Vreteno）进行了表征，并证明了该蛋白在初级 piRNA 生物发生中的关键作用。Vreteno 与初级途径成分 Piwi、Armitage、Yb 和 Zucchini 物理和/或遗传相互作用。Vreteno 还与 Tdrd12 同源物 CG11133（Yb 的兄弟）和 CG31755（Yb 的姐妹）相互作用，这些同源物对于生殖细胞中的初级 piRNA 途径是必需的，并且可能取代相关但在体细胞中特异性的因子 Yb 的功能。
