PURIFICATION OF TUBULIN AND ASSOCIATED HIGH MOLECULAR-WEIGHT PROTEINS FROM PORCINE BRAIN AND CHARACTERIZATION OF MICROTUBULE ASSEMBLY INVITRO
PURIFICATION OF TUBULIN AND ASSOCIATED HIGH MOLECULAR-WEIGHT PROTEINS FROM PORCINE BRAIN AND CHARACTERIZATION OF MICROTUBULE ASSEMBLY INVITRO
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DOI：
10.1111/j.1749-6632.1975.tb19196.x
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发表时间：
1975-01-01
影响因子：
5.2
通讯作者：
JOHNSON, KA
中科院分区：
文献类型：
--
作者：
BORISY, GG;MARCUM, JM;JOHNSON, KA
需要解释决定微管起始、生长、方向性和空间定位的翻译后机制。为了通过实验分析这些问题，已经尝试在体外建立聚合系统，其中可以确定调节微管组装的分子成分。由于这一问题的生化性质，我们选择了含有丰富微管蛋白的脑组织作为实验材料。比较生物化学表明，来自不同细胞类型的微管蛋白具有相似的特性(见Olmsted和Borisy，‘Stephens, ’ ？以及Wilson和Bryan的评论)：因此，关于脑微管蛋白的研究结果可能适用于一般的细胞质微管。本报告的目的是描述微管蛋白及其相关高分子量蛋白的纯化，以及体外微管聚合的特点。在本文中，我们将讨论一些可能涉及到装配过程的一般规则的因素。具体来说，将考虑以下问题：(1)微管蛋白以外的蛋白质是否与微管相关？(2)离子强度、pH等环境条件如何影响聚合？(3)核苷酸在聚合中起什么作用？(4)二价阳离子是抑制还是刺激组装？(5)体外小管组装是一个平衡过程吗？(6)小管装配的总体机理是什么？(7)中间产物是否参与小管的形成和生长？
Explanations are required for the post-translational mechanisms that determine the initiation, growth, directionality, and spatial localization of microtubules. To analyze these problems experimentally, attempts have been made to establish polymerization systems in vitro in which the molecular components that regulate microtubule assembly might be identified. Because of the biochemical nature of this problem, brain tissue, which contains abundant microtubule protein, was chosen as the experimental material. Comparative biochemistry has shown that tubulin from diverse cell types has similar properties (see Olmsted and Borisy,'Stephens,? and Wilson and Bryan for reviews): therefore, the findings of studies on brain tubulin may be applicable to cytoplasmic microtubules in general.The purpose of this report is to describe the purification of tubulin and associated high-molecular-weight proteins, and the characteristics of microtubule polymerization in vitro. In this paper, we will discuss some of the factors that might be involved in the general regulation of the assembly process. Specifically, the following questions will be considered:(1) Are proteins other than tubulin associated with microtubules?(2) How do environmental conditions, such as ionic strength and pH, affect polymerization?(3) What role do nucleotides have in polymerization?(4) Do divalent cations inhibit or stimulate assembly?(5) Is tubule assembly in vitro an equilibrium process?(6) What is the overall mechanism of tubule assembly?(7) Are intermediates involved in the initiation and growth of tubules?