Endophilin B is required for the Drosophila oocyte to endocytose yolk downstream of Oskar
Endophilin B is required for the Drosophila oocyte to endocytose yolk downstream of Oskar
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DOI：
10.1242/dev.097022
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发表时间：
2014-02
期刊：
影响因子：
4.6
通讯作者：
Y. Tsai;Wei Chiang;Willisa Liou;Wei-Hao Lee;Yu-Wei Chang;Pei-Yu Wang;Yi-Chen Li;Tsubasa Tanaka
中科院分区：
文献类型：
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作者：
Y. Tsai;Wei Chiang;Willisa Liou;Wei-Hao Lee;Yu-Wei Chang;Pei-Yu Wang;Yi-Chen Li;Tsubasa Tanaka
营养环境对果蝇卵子发生至关重要，它控制着调节卵黄产生和卵黄发生的激素条件。在这里，我们发现，果蝇Endophilin B（D-EndoB），endophilin家族的成员，是必需的蛋黄内吞作用，因为它调节膜动力学在发育卵室。D-EndoB的缺失导致蛋黄含量减少，类似于无蛋黄突变体中所见，并且还导致繁殖力差。此外，突变的卵室表现出逮捕在previtellogenic阶段。D-EndoB在卵母细胞后极以Oskar依赖的方式显示新月形定位;然而，它并不有助于极胞质组装。在超微结构分析中发现D-EndoB与Long Oskar和Yolkless部分共定位于内吞膜。使用FM 4 -64染料掺入测定，还发现D-EndoB促进卵母细胞中的内吞作用。当在卵母细胞中表达全长D-endoBFL或D-endoBΔ SH 3突变体转基因时，D-endoB突变体中卵黄发生的阻断和繁殖力的缺陷得到恢复。相比之下，截短的N-BAR结构域的D-EndoB只有部分挽救这些缺陷。综上所述，这些结果使我们能够得出结论，D-EndoB有助于Oskar下游的内吞活性，通过其N-BAR结构域在卵黄摄取过程中促进膜动力学，从而导致卵黄发生的正常进展。
The nutritional environment is crucial for Drosophila oogenesis in terms of controlling hormonal conditions that regulate yolk production and the progress of vitellogenesis. Here, we discovered that Drosophila Endophilin B (D-EndoB), a member of the endophilin family, is required for yolk endocytosis as it regulates membrane dynamics in developing egg chambers. Loss of D-EndoB leads to yolk content reduction, similar to that seen in yolkless mutants, and also causes poor fecundity. In addition, mutant egg chambers exhibit an arrest at the previtellogenic stage. D-EndoB displayed a crescent localization at the oocyte posterior pole in an Oskar-dependent manner; however, it did not contribute to pole plasm assembly. D-EndoB was found to partially colocalize with Long Oskar and Yolkless at the endocytic membranes in ultrastructure analysis. Using an FM4-64 dye incorporation assay, D-EndoB was also found to promote endocytosis in the oocyte. When expressing the full-length D-endoBFL or D-endoBΔSH3 mutant transgenes in oocytes, the blockage of vitellogenesis and the defect in fecundity in D-endoB mutants was restored. By contrast, a truncated N-BAR domain of the D-EndoB only partially rescued these defects. Taken together, these results allow us to conclude that D-EndoB contributes to the endocytic activity downstream of Oskar by facilitating membrane dynamics through its N-BAR domain in the yolk uptake process, thereby leading to normal progression of vitellogenesis.