Couchie D, Gache Y, Mavilia C, Guilleminot J, Bridoux A M, Nivez M P, Nunez J
Unité INSERM U 282-CNRS, Hôpital Henri-Mondor, Créteil, France.
C R Acad Sci III. 1993;316(4):404-9.
Several variants of the microtubule-associated tau proteins, are expressed during brain development and in adulthood. These entities are required to define the polarity of the neuron and the architecture of the axon but differ in sequence and in their microtubule polymerizing activity. Here, we describe a new group of high molecular weight tau proteins that contain one or two additional exons of 711 and 198 bp in their middle region and a variable N-terminal domain. These high molecular weight tau variants are preferentially expressed in the peripheral nervous system. Immunohistochemical studies showed that they are also present in the dorsal horn of the spinal cord where they are probably transported by sensory fibers arising in the periphery. However, a minor fraction of these proteins is present in the motor neurons of the ventral horn. Similar studies were performed with the neuroblastoma N115 cell line which can be differentiated in vitro and expresses only high molecular weight tau forms. In the non differentiated cells, tau antibodies label the domain of the cell body localized around the centrosome whereas, after differentiation, the cell process facing this structure is also stained. These data suggest that axonal polarity is predetermined by the localization of tau proteins in the domain of the cell body defined by the centrosome.
微管相关的tau蛋白有多种变体，在大脑发育过程中和成年期均有表达。这些蛋白对于确定神经元的极性和轴突的结构是必需的，但在序列和微管聚合活性方面存在差异。在这里，我们描述了一组新的高分子量tau蛋白，它们在中间区域包含一个或两个额外的711和198 bp外显子以及一个可变的N端结构域。这些高分子量tau变体优先在外周神经系统中表达。免疫组织化学研究表明，它们也存在于脊髓背角，可能由外周产生的感觉纤维运输至此。然而，这些蛋白的一小部分存在于腹角的运动神经元中。我们对神经母细胞瘤N115细胞系进行了类似研究，该细胞系可在体外分化，且仅表达高分子量tau形式。在未分化的细胞中，tau抗体标记位于中心体周围的细胞体区域，而在分化后，朝向该结构的细胞突起也被染色。这些数据表明，轴突极性由tau蛋白在由中心体定义的细胞体区域中的定位预先确定。
