Maruta H, Greer K, Rosenbaum J L
J Cell Biol. 1986 Aug;103(2):571-9. doi: 10.1083/jcb.103.2.571.
A tight association between Chlamydomonas alpha-tubulin acetyltransferase (TAT) and flagellar axonemes, and the cytoplasmic localization of both tubulin deacetylase (TDA) and an inhibitor of tubulin acetylation have been demonstrated by the use of calf brain tubulin as substrate for these enzymes. A major axonemal TAT of 130 kD has been solubilized by high salt treatment, purified, and characterized. Using the Chlamydomonas TAT with brain tubulin as substrate, we have studied the effects of acetylation on the assembly and disassembly of microtubules in vitro. We also determined the relative rates of acetylation of tubulin dimers and polymers. The acetylation does not significantly affect the temperature-dependent polymerization or depolymerization of tubulin in vitro. Furthermore, polymerization of tubulin is not a prerequisite for the acetylation, although the polymer is a better substrate for TAT than the dimer. The acetylation is sensitive to calcium ions which completely inhibit the acetylation of both dimers and polymers of tubulin. Acetylation of the dimer is not inhibited by colchicine; the effect of colchicine on acetylation of the polymer can be explained by its depolymerizing effect on the polymer.
通过使用小牛脑微管蛋白作为这些酶的底物，已证明衣藻α-微管蛋白乙酰转移酶（TAT）与鞭毛轴丝之间存在紧密关联，并且微管蛋白去乙酰化酶（TDA）和微管蛋白乙酰化抑制剂均定位于细胞质中。一种130 kD的主要轴丝TAT已通过高盐处理溶解、纯化并进行了表征。以脑微管蛋白为底物，使用衣藻TAT，我们研究了乙酰化对体外微管组装和解聚的影响。我们还测定了微管蛋白二聚体和聚合物的相对乙酰化速率。乙酰化在体外对微管蛋白的温度依赖性聚合或解聚没有显著影响。此外，微管蛋白的聚合不是乙酰化的先决条件，尽管聚合物比二聚体是TAT更好的底物。乙酰化对钙离子敏感，钙离子完全抑制微管蛋白二聚体和聚合物的乙酰化。秋水仙碱不抑制二聚体的乙酰化；秋水仙碱对聚合物乙酰化的影响可以用其对聚合物的解聚作用来解释。
