Ensconsin空间解除Kinesin-1自抑制调控ncMTOCs定位并塑造微管网络
Spatial relief of Kinesin-1 auto-inhibition by Ensconsin regulates ncMTOCs localization and shapes microtubule networks
摘要
研究以果蝇卵子发生为模型,发现Kinesin重链激活因子Ensconsin通过微管结合、Dynein介导运输及Ninein锚定在卵母细胞中富集。Ensconsin富集缺失会减少皮层非中心体微管组织中心(ncMTOCs)、削弱微管成核、破坏微管组织及微管依赖的胞质流;无法结合Ensconsin的Khc突变体呈组成性激活,并可部分挽救Ensconsin缺失表型,支持解除自抑制模型。结论提示Khc-Ensconsin复合物通过空间调控招募ncMTOCs并重塑卵母细胞微管骨架。
原文摘要
During Drosophila oogenesis, the organization of microtubules (MTs) drives polarized transport and cytoplasmic flows. Although Kinesin-1 plays a central role in these processes, its molecular and spatial regulation remains poorly understood. Here, we show that Ensconsin, an activator of the Kinesin heavy chain (Khc), is enriched in the oocyte through MT binding, Dynein-mediated transport and by the MT-anchoring protein Ninein. Strikingly, loss of Ensconsin enrichment reduces cortical non-centrosomal microtubule-organizing centers (ncMTOCs), weakens MT nucleation, impairs MT organization and MT-dependent cytoplasmic flows. Additionally, a specific Khc variant unable to bind Ensconsin, is constitutively active and is able to partly rescue the loss of Ensconsin in oocyte and neural stem cells, thereby providing in vivo support for the relief-of-auto-inhibition model. Overall, we uncover a novel function for the Khc-Ensconsin complex in the recruitment of ncMTOCs in oocytes for MT organization. Our findings are in line with a model in which Ensconsin enrichment acts as a rheostat to modulate Khc activation, ensuring precise spatial remodeling of the microtubule cytoskeleton in the oocyte.
推荐理由:机制新颖、遗传学验证较扎实,适合关注卵母细胞微管骨架与ncMTOCs的基础研究者;但与人类辅助生殖临床和实验室转化距离较远。
文献解读
尚未生成。