Adio Sarah, Reth Jolante, Bathe Friederike, Woehlke Günther
Institute for Cell Biology, University of Munich, Schillerstr. 42, D-80336, Munich, Germany.
J Muscle Res Cell Motil. 2006;27(2):153-60. doi: 10.1007/s10974-005-9054-1. Epub 2006 Feb 1.
Kinesin-1 microtubule motors are common kinesin motors from protozoa, fungi and animals. They transport vesicular or particle cargo in a strictly regulated manner. The relatively well-studied tail inhibition mechanism is based on a conformational change that leads to an interaction of Kinesin-1's tail with the junction of neck and hinge regions. This folding causes a decrease in microtubule binding and motor activity. In fungal Kinesin-1 motors several lines of evidence suggest that a conserved tyrosine in the neck coiled-coil mediates this inhibition. In the active state, a region surrounding a conserved tryptophan in the hinge stabilises the neck coiled-coil, and prevents the tyrosine from inhibiting. Although animal and fungal Kinesin-1 motors are clearly homologous and function according to the same chemo-mechanical mechanism, they differ in their regulation. Unlike fungal Kinesin-1s, animal kinesins associate with light chains that are important for regulation and cargo interaction. Several proteins interacting with animal Kinesin-1 heavy or light chains are known, among them typical scaffolding proteins that seem to link Kinesin-1 to signalling pathways.
驱动蛋白-1微管马达是原生动物、真菌和动物中常见的驱动蛋白。它们以严格调控的方式运输囊泡或颗粒货物。研究相对充分的尾部抑制机制基于一种构象变化，该变化导致驱动蛋白-1的尾部与颈部和铰链区的连接处相互作用。这种折叠导致微管结合和马达活性降低。在真菌驱动蛋白-1马达中，多条证据表明颈部卷曲螺旋中的一个保守酪氨酸介导了这种抑制作用。在活性状态下，铰链区中一个保守色氨酸周围的区域稳定了颈部卷曲螺旋，并防止酪氨酸产生抑制作用。尽管动物和真菌的驱动蛋白-1马达明显同源且根据相同的化学机械机制发挥作用，但它们在调控方面存在差异。与真菌驱动蛋白-1不同，动物驱动蛋白与对调控和货物相互作用很重要的轻链相关联。已知几种与动物驱动蛋白-1重链或轻链相互作用的蛋白质，其中包括典型的支架蛋白，它们似乎将驱动蛋白-1与信号通路联系起来。
