Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.
Differential Nanos 2 protein stability results in selective germ cell accumulation in the sea urchin.
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DOI：
10.1016/j.ydbio.2016.07.007
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发表时间：
2016-10-01
影响因子：
2.7
通讯作者：
Wessel GM
中科院分区：
文献类型：
--
作者：
Oulhen N;Wessel GM
Nanos是原始生殖细胞存活和维持所需的翻译调节因子。在海胆（strongylocentrrotus purpuratus, Sp）中，Nanos 2 mRNA广泛转录，但在小微粒（sMic）谱系中特异性积累，部分原因是3'UTR元件GNARLE导致体细胞周转，但在sMic中保留。在这里，我们发现Nanos 2蛋白也是选择性稳定的；它最初在整个胚胎中被翻译，但在未来的体细胞中被转换，只保留在sMics中，即这种动物未来的生殖系。Nanos蛋白的这种差异稳定性依赖于开放阅读框（ORF），而不依赖于sumo化和泛素化途径。对ORF的操作表明，纳米蛋白N端的68个氨基酸对其在sMics中的稳定性至关重要，而锌指附近的45个氨基酸元素则针对其降解。此外，纳米蛋白的调控是细胞自主的，随着种系的形成。这些结果是通过选择性RNA保留、独特的翻译控制机制以及现在定义的Nanos蛋白稳定性的结合，在种系中独特存在Nanos的范例。
Nanos is a translational regulator required for the survival and maintenance of primordial germ cells. In the sea urchin, Strongylocentrotus purpuratus (Sp), Nanos 2 mRNA is broadly transcribed but accumulates specifically in the small micromere (sMic) lineage, in part because of the 3′UTR element GNARLE leads to turnover in somatic cells but retention in the sMics. Here we found that the Nanos 2 protein is also selectively stabilized; it is initially translated throughout the embryo but turned over in the future somatic cells and retained only in the sMics, the future germ line in this animal. This differential stability of Nanos protein is dependent on the open reading frame (ORF), and is independent of the sumoylation and ubiquitylation pathways. Manipulation of the ORF indicates that 68 amino acids in the N terminus of the Nanos protein are essential for its stability in the sMics whereas a 45 amino acid element adjacent to the zinc fingers targets its degradation. Further, this regulation of Nanos protein is cell autonomous, following formation of the germ line. These results are paradigmatic for the unique presence of Nanos in the germ line by a combination of selective RNA retention, distinctive translational control mechanisms, and now also by defined Nanos protein stability.