Bré M H, Karsenti E
EMBL, Heidelberg, Federal Republic of Germany.
Cell Motil Cytoskeleton. 1990;15(2):88-98. doi: 10.1002/cm.970150205.
In this paper, we report on the effect of brain microtubule-associated proteins (MAPs) on the dynamic instability of microtubules as well as on the nucleation activity of purified centrosomes. Under our experimental conditions, tau and MAP2 have similar effects on microtubule nucleation and dynamic instability. Tau increases the apparent elongation rate of microtubules in proportion to its molar ratio to tubulin, and we present evidence indicating that this is due to a reduction of microtubule instability rather than to an increase of the on rate of tubulin subunits at the end of growing microtubules. Increasing the molar ratio of tau over tubulin leads also to an increase in the average number of microtubules nucleated per centrosome. This number remains constant with time. This suggests that the number of centrosome-nucleated microtubules at steady state can be determined by factors that are not necessarily irreversibly bound to centrosomes but, rather, affect the dynamic properties of microtubules.
在本文中，我们报告了脑微管相关蛋白（MAPs）对微管动态不稳定性以及纯化中心体成核活性的影响。在我们的实验条件下，tau蛋白和微管相关蛋白2（MAP2）对微管成核和动态不稳定性具有相似的作用。tau蛋白按其与微管蛋白的摩尔比增加微管的表观伸长率，并且我们提供的证据表明，这是由于微管不稳定性降低，而非微管蛋白亚基在生长微管末端的结合速率增加所致。增加tau蛋白与微管蛋白的摩尔比也会导致每个中心体成核的微管平均数量增加。该数量随时间保持恒定。这表明稳态下由中心体成核的微管数量可由不一定不可逆结合于中心体但会影响微管动态特性的因素决定。
