Bam and Bgcn antagonize Nanos-dependent germ-line stem cell maintenance
Bam and Bgcn antagonize Nanos-dependent germ-line stem cell maintenance
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DOI：
10.1073/pnas.0901452106
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发表时间：
2009-06-09
影响因子：
11.1
通讯作者：
Maines, Jean Z.
中科院分区：
文献类型：
--
作者：
Li, Yun;Minor, Nicole T.;Maines, Jean Z.
果蝇卵巢中生殖系干细胞 (GSC) 自我更新和分化之间的平衡是由 Nanos (Nos)-Pumilio 翻译抑制复合物与关键分化因子 Bam 表达之间的拮抗关系介导的，该复合物促进 GSC 自我更新。在这里，我们发现 Bam 和 Nos 蛋白在年轻生殖细胞中以相反的模式表达。 Bam 表达细胞中 Nos 的抑制取决于 nos 3'-UTR 中的序列，表明 Nos 受到翻译抑制的调节。异位 Bam 导致 GSC 分化，这种活性取决于内源性 nos 3'-UTR 序列。先前的证据表明 Bgcn 是 Bam 驱动分化能力的必然因素，我们现在报道 Bam 与 Bgcn 形成复合物，Bgcn 是一种与 RNA 相互作用的 DExH-box 多肽相关的蛋白质。总之，这些观察结果表明 Bam-Bgcn 共同作用来拮抗 Nos 表达；因此，去抑制囊胚细胞促进因子。这些发现强调了翻译抑制在平衡干细胞自我更新和分化中的重要性。
The balance between germ-line stem cell (GSC) self-renewal and differentiation in Drosophila ovaries is mediated by the antagonistic relationship between the Nanos (Nos)-Pumilio translational repressor complex, which promotes GSC self-renewal, and expression of Bam, a key differentiation factor. Here, we find that Bam and Nos proteins are expressed in reciprocal patterns in young germ cells. Repression of Nos in Bam-expressing cells depends on sequences in the nos 3'-UTR, suggesting that Nos is regulated by translational repression. Ectopic Bam causes differentiation of GSCs, and this activity depends on the endogenous nos 3'-UTR sequence. Previous evidence showed that Bgcn is an obligate factor for the ability of Bam to drive differentiation, and we now report that Bam forms a complex with Bgcn, a protein related to the RNA-interacting DExH-box polypeptides. Together, these observations suggest that Bam-Bgcn act together to antagonize Nos expression; thus, derepressing cystoblast-promoting factors. These findings emphasize the importance of translational repression in balancing stem cell self-renewal and differentiation.