Mizoguchi A, Arakawa M, Masutani M, Tamekane A, Yamaguchi H, Minami N, Takai Y, Ide C
Department of Anatomy, Kobe University School of Medicine, Japan.
Biochem Biophys Res Commun. 1992 Aug 14;186(3):1345-52. doi: 10.1016/s0006-291x(05)81554-2.
smg p25A is a small G protein which has been suggested to regulate neurotransmitter release from the synapses. We investigated here the ultrastructural localization of this small G protein in the rat neuromuscular junction by an immunoperoxidase method. The results showed that smg p25A was distributed non-uniformly on the presynaptic plasma membrane and among the synaptic vesicles with the focal accumulation on the discrete presynaptic sites which corresponded to the active zones, the regions of the presynaptic plasma membrane specialized for the exocytosis of the synaptic vesicles. This unique distribution of smg p25A suggests that it plays an important role in the attachment and fusion of the synaptic vesicles with the active zones.
Smg p25A是一种小G蛋白，有人认为它可调节突触处神经递质的释放。我们在此通过免疫过氧化物酶法研究了这种小G蛋白在大鼠神经肌肉接头处的超微结构定位。结果显示，Smg p25A在突触前质膜上分布不均匀，在突触小泡之间也有分布，在与活性区相对应的离散突触前位点有局灶性聚集，活性区是突触前质膜上专门用于突触小泡胞吐作用的区域。Smg p25A的这种独特分布表明它在突触小泡与活性区的附着和融合中起重要作用。
