Aguado F, Majó G, Ruiz-Montasell B, Llorens J, Marsal J, Blasi J
Departament de Biologia Cellular i Anatomia Patològica, Facultat de Medicina, Hospital de Bellvitge, Barcelona, Spain.
Neuroscience. 1999 Jan;88(2):437-46. doi: 10.1016/s0306-4522(98)00247-4.
Syntaxin 1 has been shown to play an outstanding role in synaptic vesicle exocytosis. Two isoforms of this protein are expressed in neurons, syntaxin 1A and 1B. However, the physiological significance of the occurrence of such closely related isoforms is not still understood. Here, by means of isoform-specific immunocytochemistry, we show that syntaxin 1A and 1B display different patterns of expression in the rat peripheral nervous system. Nerve terminals of sensory neurons reaching the spinal cord were clearly enriched in immunoreactive syntaxin 1A. Both isoforms were detected in cell bodies of sensory neurons at the dorsal root ganglia, although specific immunolabelling displayed very different patterns at the cellular level. Motor endplates and muscle spindles were only immunostained for syntaxin 1B. Syntaxin 1A was mainly associated with nerve fibres reaching small blood vessels. In addition, nerve plexuses of the enteric nervous system showed immunostaining for both syntaxin isoforms. The different distribution pattern of the two neuronal syntaxin isoforms in the rat peripheral nervous system could be related to isoform-specific biochemical properties involved in the exocytotic process.
syntaxin 1已被证明在突触小泡胞吐作用中发挥着重要作用。这种蛋白质的两种异构体在神经元中表达，即syntaxin 1A和1B。然而，这种密切相关的异构体出现的生理意义仍不清楚。在这里，通过异构体特异性免疫细胞化学，我们表明syntaxin 1A和1B在大鼠外周神经系统中表现出不同的表达模式。到达脊髓的感觉神经元的神经末梢明显富含免疫反应性syntaxin 1A。在背根神经节的感觉神经元细胞体中检测到这两种异构体，尽管特异性免疫标记在细胞水平上显示出非常不同的模式。运动终板和肌梭仅对syntaxin 1B进行免疫染色。Syntaxin 1A主要与到达小血管的神经纤维相关。此外，肠神经系统的神经丛对两种syntaxin异构体均显示免疫染色。大鼠外周神经系统中两种神经元syntaxin异构体的不同分布模式可能与胞吐过程中涉及的异构体特异性生化特性有关。
