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Nogo家族是一类神经轴突生长抑制因子家族,目前成员包括Nogo-A,Nogo-B,Nogo-C三个亚型。Nogo家族成员因C末端具有保守的RHD结构域而归属于RTNs家族,表明它们的分布和功能与内质网密切相关。Nogo家族C末端还具有一个进化保守的66氨基酸的功能段称为Nogo-66,体外表达的Nogo-66片段具有抑制神经突生长的作用。Nogo家族成员结构上的区别主要表现在不同剪切长短的N末端序列。Nogo-A主要在中枢和外周神经系统中广泛分布,Nogo-C主要分布在骨骼肌,而Nogo-B则几乎遍布于各种组织与细胞之中。目前,发现可介导Nogo胞内信号转导通路的受体主要是膜外糖蛋白偶联的NgR和跨膜受体p75NTR组成的共受体,但NgR与Nogo-A在胚胎发育中时空表达并不同步提示可能还有其它受体存在。虽然Nogo家族作为神经轴突生长抑制因子被发现,但越来越多的研究表明其可能在胚胎发育、细胞凋亡或神经退行性变等重大事件中扮演重要角色。本文拟就Nogo家族迄今为止突出的研究进展作一综述,旨在为下一步的功能研究工作提供理论参考和依据。
Nogo family is a family of axon growth inhibitory factor family, the current members include Nogo-A, Nogo-B, Nogo-C three subtypes. The members of the Nogo family belong to the RTNs family due to the C-terminal conserved RHD domains, indicating that their distribution and function are closely related to the endoplasmic reticulum. The Nogo family also has an evolutionarily conserved 66-amino-acid functionalized C-terminal protein called Nogo-66. In vitro Nogo-66 has an inhibitory effect on neurite outgrowth. Structural differences among Nogo family members are mainly observed in N-terminal sequences of different lengths of cut. Nogo-A is predominantly found in the central and peripheral nervous systems, Nogo-C is predominantly skeletal muscle, and Nogo-B is found in almost all tissues and cells. At present, it is found that the receptors that mediate Nogo intracellular signal transduction pathway are mainly co-receptors composed of extracellular glycoprotein-coupled NgR and transmembrane receptor p75NTR, but NgR and Nogo-A are spatially expressed in embryonic development It does not suggest that there may be other receptors as well. Although the Nogo family has been identified as a neuro-axon growth inhibitory factor, more and more studies indicate that it may play an important role in such major events as embryonic development, apoptosis or neurodegeneration. This article intends to summarize the outstanding research progress so far of the Nogo family and provide a theoretical reference and basis for the next functional research.