Francon J, Lennon A M, Fellous A, Mareck A, Pierre M, Nunez J
Eur J Biochem. 1982 Dec 15;129(2):465-71. doi: 10.1111/j.1432-1033.1982.tb07072.x.
Developmental changes in the composition of brain microtubule-associated proteins have been studied in three species: the rat and the mouse, which are characterized by post-natal brain development, and the guinea-pig, whose brain is mature at birth. 1. At an adult stage, and whatever the species, two major microtubule-associated proteins, which have been referred to MAP2 and tau, have been identified by polyacrylamide gel electrophoresis. Rat tau is composed of four closely spaced bands; mouse tau contains only three components with one of them being present in higher proportion than the others; adult guinea-pig tau is essentially present as a single band. 2. Microtubule-associated proteins were also prepared at different stages of brain development. In the three species only two bands were seen in the tau region at immature stages of development (fast tau and slow tau). However adult tau factors progressively replace the young entities. In contrast, only small changes were seen in the proportion of MAP2. 3. Peptide mapping analysis of the purified tau entities confirmed that the four adult rat proteins are very similar. In contrast, peptide mapping of the two young rat tau proteins were very different from each other and from those of the adult ones. Peptide mappings of young and adult MAP2 were only slightly different. 4. The activities of young tau proteins and young MAP2 in promoting pure tubulin assembly were much lower than those of the adult ones. Young fast tau and young slow tau were purified and both show to be active in promoting pure tubulin polymerization. 5. These data demonstrate the existence of two types of heterogeneity of microtubule-associated proteins: plurality of protein species at every stage of brain development and changes in composition and activity dependent on development.
大鼠和小鼠，其特点是出生后脑发育；豚鼠，其脑在出生时成熟。1. 在成年阶段，无论物种如何，通过聚丙烯酰胺凝胶电泳鉴定出两种主要的微管相关蛋白，分别称为MAP2和tau。大鼠tau由四条紧密间隔的条带组成；小鼠tau仅包含三种成分，其中一种成分的比例高于其他成分；成年豚鼠tau基本上以单一条带形式存在。2. 还在脑发育的不同阶段制备了微管相关蛋白。在这三种物种中，在发育不成熟阶段的tau区域仅可见两条带（快速tau和慢速tau）。然而，成年tau因子逐渐取代了年轻的蛋白。相比之下，MAP2的比例仅出现了微小变化。3. 对纯化的tau蛋白的肽图谱分析证实，四种成年大鼠蛋白非常相似。相比之下，两种年轻大鼠tau蛋白的肽图谱彼此之间以及与成年大鼠的肽图谱都非常不同。年轻和成年MAP2的肽图谱只有轻微差异。4. 年轻tau蛋白和年轻MAP2促进纯微管蛋白组装的活性远低于成年蛋白。纯化了年轻快速tau和年轻慢速tau，两者均显示出促进纯微管蛋白聚合的活性。5. 这些数据证明了微管相关蛋白存在两种异质性：脑发育每个阶段的多种蛋白种类以及组成和活性随发育而变化。
