Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 Utrecht, the Netherlands.
Cell Biology, Department of Biology, Faculty of Science, Utrecht University, 3584 Utrecht, the Netherlands.
Cell Rep. 2019 Feb 19;26(8):1988-1999.e6. doi: 10.1016/j.celrep.2019.01.084.
The motor protein kinesin-1 plays an important role in polarized sorting of transport vesicles to the axon. However, the mechanism by which the axonal entry of kinesin-1-dependent cargo transport is regulated remains unclear. Microtubule-associated protein MAP7 (ensconsin in Drosophila) is an essential kinesin-1 cofactor and promotes kinesin-1 recruitment to microtubules. Here, we found that MAP7 family member MAP7D2 concentrates at the proximal axon, where it overlaps with the axon initial segment and interacts with kinesin-1. Depletion of MAP7D2 results in reduced axonal cargo entry and defects in axon development and neuronal migration. We propose a model in which MAP7D2 in the proximal axon locally promotes kinesin-1-mediated cargo entry into the axon.
驱动蛋白 kinesin-1 在将运输囊泡极性分拣到轴突中起着重要作用。然而，kinesin-1 依赖性货物运输进入轴突的调节机制仍不清楚。微管相关蛋白 MAP7（果蝇中的 ensconsin）是一种必需的 kinesin-1 辅助因子，可促进 kinesin-1 与微管的募集。在这里，我们发现 MAP7 家族成员 MAP7D2 集中在轴突的近端，与轴突起始段重叠，并与 kinesin-1 相互作用。MAP7D2 的耗竭导致轴突货物进入减少，并导致轴突发育和神经元迁移缺陷。我们提出了一个模型，即近端轴突中的 MAP7D2 局部促进 kinesin-1 介导的货物进入轴突。
