Vale R D, Schnapp B J, Mitchison T, Steuer E, Reese T S, Sheetz M P
Cell. 1985 Dec;43(3 Pt 2):623-32. doi: 10.1016/0092-8674(85)90234-x.
Single microtubules from squid axoplasm support bidirectional movement of organelles. We previously purified a microtubule translocator (kinesin) that moves latex beads in only one direction along microtubules. In this study, a polar array of microtubules assembled off of centrosomes in vitro was used to demonstrate that kinesin moves latex beads from the minus to the plus ends of microtubules, a direction that corresponds to anterograde transport in the axon. A crude solubilized fraction from squid axoplasm (S1a), however, generates bidirectional movement of beads along microtubules. Retrograde bead movement (1.4 micron/sec) is inhibited by N-ethylmaleimide and 20 microM vanadate while anterograde movement (0.6 micron/sec) is unaffected by these agents. Furthermore, a monoclonal antibody against kinesin, when coupled to Sepharose, removes the anterograde, but not the retrograde, bead translocator from S1a. These results indicate that there is a retrograde bead translocator which is pharmacologically and immunologically distinct from kinesin.
来自鱿鱼轴质的单个微管支持细胞器的双向移动。我们之前纯化了一种微管转运体（驱动蛋白），它只能沿微管在一个方向上移动乳胶珠。在本研究中，体外从中心体组装的微管极性阵列被用于证明驱动蛋白将乳胶珠从微管的负端移向正端，这个方向对应于轴突中的顺行运输。然而，鱿鱼轴质的粗可溶性组分（S1a）能使珠子沿微管进行双向移动。逆向珠子移动（1.4微米/秒）受到N - 乙基马来酰亚胺和20微摩尔钒酸盐的抑制，而顺行移动（0.6微米/秒）不受这些试剂影响。此外，一种抗驱动蛋白的单克隆抗体与琼脂糖偶联后，能从S1a中去除顺行而非逆行的珠子转运体。这些结果表明存在一种逆向珠子转运体，其在药理学和免疫学上与驱动蛋白不同。
