The Drosophila RNA Helicase Belle (DDX3) Non-Autonomously Suppresses Germline Tumorigenesis Via Regulation of a Specific mRNA Set
The Drosophila RNA Helicase Belle (DDX3) Non-Autonomously Suppresses Germline Tumorigenesis Via Regulation of a Specific mRNA Set
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DOI：
10.3390/cells9030550
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发表时间：
2020-02
期刊：
影响因子：
6
通讯作者：
A. A. Kotov-A.;Baira Godneeva;O. Olenkina;V. E. Adashev;M. V. Trostnikov;L. V. Olenina
中科院分区：
文献类型：
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作者：
A. A. Kotov-A.;Baira Godneeva;O. Olenkina;V. E. Adashev;M. V. Trostnikov;L. V. Olenina
DDX 3亚家族DEAD盒RNA解旋酶是真核生物RNA代谢的重要发育调节因子。贝儿是果蝇中唯一的DDX 3直系同源基因，是果蝇生存力、生育力和生殖系干细胞维持所必需的。贝儿参与不同组织中靶mRNA的翻译激活和抑制;然而，睾丸中贝儿的直接靶点基本上是未知的。我们发现，睾丸囊肿细胞中的贝儿RNAi敲低导致生殖细胞和囊肿细胞之间的粘附破坏，并产生肿瘤样干细胞样生殖细胞簇。在贝儿基因敲低的睾丸中，囊肿细胞中β-整合素的异位表达挽救了精子发生的早期阶段，表明整合素粘附复合物是囊肿中体细胞和生殖细胞之间相互作用所必需的。为了详细说明贝儿在精子发生中的功能，我们进行了交联免疫沉淀和测序（CLIP-seq）分析，并鉴定了睾丸中与贝儿相互作用的多种mRNA。贝儿的一组靶点包括对于预防生殖细胞肿瘤样簇和维持精子发生至关重要的蛋白质转录本。根据我们的假设，许多mRNA靶点的翻译失败会增加在睾丸中观察到的发育缺陷，其中贝儿敲除在囊肿细胞和生殖细胞中。
DDX3 subfamily DEAD-box RNA helicases are essential developmental regulators of RNA metabolism in eukaryotes. belle, the single DDX3 ortholog in Drosophila, is required for fly viability, fertility, and germline stem cell maintenance. Belle is involved both in translational activation and repression of target mRNAs in different tissues; however, direct targets of Belle in the testes are essentially unknown. Here we showed that belle RNAi knockdown in testis cyst cells caused a disruption of adhesion between germ and cyst cells and generation of tumor-like clusters of stem-like germ cells. Ectopic expression of β-integrin in cyst cells rescued early stages of spermatogenesis in belle knockdown testes, indicating that integrin adhesion complexes are required for the interaction between somatic and germ cells in a cyst. To address Belle functions in spermatogenesis in detail we performed cross-linking immunoprecipitation and sequencing (CLIP-seq) analysis and identified multiple mRNAs that interacted with Belle in the testes. The set of Belle targets includes transcripts of proteins that are essential for preventing the tumor-like clusters of germ cells and for sustaining spermatogenesis. By our hypothesis, failures in the translation of a number of mRNA targets additively contribute to developmental defects observed in the testes with belle knockdowns both in cyst cells and in the germline.