Shinohara H, Asano T, Kato K
Department of Biochemistry, Institute for Developmental Research, Aichi Prefectural Colony, Japan.
J Neurosci. 1992 Apr;12(4):1275-9. doi: 10.1523/JNEUROSCI.12-04-01275.1992.
To clarify the functional differences among G-proteins, we investigated the localization of Gi and Go in the olfactory bulb of rats by both immunohistochemical and immunochemical techniques, using purified antibodies specific to the alpha-subunits of Gi1 (Gi1 alpha), Gi2 (Gi2 alpha), and Go (Go alpha), respectively. We found that Gi2 alpha is localized exclusively in the accessory olfactory bulb, but it is present at only low levels in the main olfactory bulb. The unique pattern of immunoreactivity specific for Gi2 alpha and Go alpha within the glomeruli of the accessory olfactory bulb and the results of immunoassays indicate that the accessory olfactory bulb is divided into two parts: the anterior region is rich in Gi2, while the posterior region is rich in Go. These findings suggest that the accessory olfactory bulb has two different functions. In addition, we found that the concentration of Gi2 alpha in the accessory olfactory bulb increases during puberty and reaches the adult level at 12 weeks after birth, while that in the main olfactory bulb remains constant. By contrast, the concentrations of Go alpha in the accessory olfactory bulb and the main olfactory bulb increase with similar kinetics. These findings suggest that Gi2 is a key protein in signal transduction in the accessory olfactory bulb, and increases in its level seem to be related to sexual maturation.
为了阐明G蛋白之间的功能差异，我们分别使用针对Gi1（Gi1α）、Gi2（Gi2α）和Go（Goα）α亚基的纯化抗体，通过免疫组织化学和免疫化学技术研究了大鼠嗅球中Gi和Go的定位。我们发现Gi2α仅定位于副嗅球，但在主嗅球中的含量很低。副嗅球肾小球内Gi2α和Goα特有的免疫反应模式以及免疫测定结果表明，副嗅球分为两部分：前部富含Gi2，而后部富含Go。这些发现表明副嗅球具有两种不同的功能。此外，我们发现副嗅球中Gi2α的浓度在青春期增加，并在出生后12周达到成年水平，而主嗅球中的浓度保持恒定。相比之下，副嗅球和主嗅球中Goα的浓度以相似的动力学增加。这些发现表明Gi2是副嗅球信号转导中的关键蛋白，其水平的增加似乎与性成熟有关。
