The plus‐tip tracking and microtubule stabilizing activities of Javelin‐like regulate microtubule organization and cell polarity
The plus‐tip tracking and microtubule stabilizing activities of Javelin‐like regulate microtubule organization and cell polarity
复制标题
Javelin-like的正尖追踪和微管稳定活性调节微管组织和细胞极性
DOI：
10.1111/febs.14944
复制
发表时间：
2019
期刊：
影响因子：
--
通讯作者：
Uri Abdu
中科院分区：
文献类型：
--
作者：
Raju Baskar;Anna Bahkrat;Tetsuhisa Otani;Housei Wada;Geula Davidov;Himanshu Pandey;Larisa Gheber;Raz Zarivach;Shigeo Hayashi;Uri Abdu
在所有真核细胞中，细胞极性是建立细胞不对称性所必需的。果蝇的毛细胞和刚毛的发育需要新鉴定的Spn-F蛋白复合物（包括Spn-F、IKKε和Javelin‐like（Jvl））来建立极性。Jvl是一种新的微管（MT）相关蛋白;然而，它调节MT组织的机制仍然未知。我们发现Jvl的过表达稳定MT，并且Jvl是在刷毛尖端稳定MT排列和在整个刷毛轴中动态MT组织所需的。在培养的细胞中低水平表达时，Jvl表现为微管加末端跟踪蛋白。我们使用酵母双杂交和GST下拉测定证明Jvl与高度保守的MT末端结合蛋白1（EB 1）物理相互作用。然而，这种相互作用对于卵母细胞和刚毛发育中的Jvl功能是不确定的。此外，使用MT结合测定，我们看到Jvl-C末端直接结合MT。我们还发现，在生殖系中由Jvl过表达引起的卵母细胞发育停滞可以通过其伴侣spn‐Fandikkε的突变来挽救，这表明Spn‐F和IKKε的复合物形成是体内Jvl功能所必需的。总之，我们的研究结果表明，微管加末端跟踪和稳定活动的Jvl是中央控制卵母细胞和刚毛的细胞极性。
Cell polarity is essential for building cell asymmetry in all eukaryotic cells.Drosophilaoocyte and bristle development require the newly characterized Spn‐F protein complex, which includes Spn‐F, IKKε, and Javelin‐like (Jvl), to establish polarity. Jvl is a novel microtubule (MT)‐associated protein; however, the mechanism by which it regulates MT organization is still unknown. We found that overexpression of Jvl stabilizes MTs and thatjvlis needed for stable MT arrangement at the bristle tip and organization of the dynamic MT throughout the bristle shaft. At low levels of expression in cultured cells, Jvl behaved as a microtubule plus‐end tracking protein. We demonstrated that Jvl physically interacts with the highly conserved MT end‐binding protein 1 (EB1) using yeast two‐hybrid and GST pull‐down assays. This interaction is, however, dispensable for Jvl function in oocyte and bristle development. In addition, using a MT‐binding assay, we saw that Jvl‐C terminus directly binds to MTs. We also revealed that oocyte developmental arrest caused by Jvl overexpression in the germline can be rescued by mutations in its partners,spn‐Fandikkε, suggesting that complex formation with Spn‐F and IKKε is required for Jvl functionin vivo. In summary, our results show that the microtubule plus‐end tracking and stabilizing activities of Jvl are central for controlling cell polarity of oocytes and bristles.