Kinsmen Laboratory of Neurological Sciences, Department of Psychiatry, University of British Columbia, Vancouver, British Columbia, Canada, V6T 1 W5.
Mol Cell Neurosci. 1991 Feb;2(1):66-70. doi: 10.1016/1044-7431(91)90040-u.
All neurotransmitter and hormone receptors that stimulate adenylyl cyclase are thought to do so via the alpha subunit of the guanine nucleotide binding (G) protein G(s). The basal ganglia contain a well-characterized dopamine-stimulated adenylyl cyclase and D1 dopamine receptors coupled to G(s) are thought to mediate this activity. We have found using immunohistochemistry, immunoblotting, and cholera toxin-dependent ADP ribosylation that the rat basal ganglia contain very high levels of a G(salpha)-like protein; however, it is distinct from the G(s) in other brain regions. Furthermore, in situ hybridization and Northern blot studies showed that the striatum contains remarkably low levels of G(salpha) mRNA. G(olf) is a G protein recently cloned from olfactory sensory neurons which can also stimulate adenylyl cyclase. We have now discovered high levels of G(olf) mRNA expression in the striatum, nucleus accumbens, and olfactory tubercle. Northern blot analyses indicate that in the striatum, G(olf) transcripts are approximately 10-fold more abundant than G(salpha) transcripts. Thus G(olf) is not an olfactory neuronspecific G protein. It is also the major stimulatory G protein in the basal ganglia, where it may couple D 1 dopamine receptors to adenylyl cyclase.
所有刺激腺苷酸环化酶的神经递质和激素受体被认为都是通过鸟嘌呤核苷酸结合（G）蛋白 G(s) 的α亚基来实现的。基底神经节含有一种特征明显的多巴胺刺激的腺苷酸环化酶，而与 G(s)偶联的 D1 多巴胺受体被认为介导了这种活性。我们通过免疫组织化学、免疫印迹和霍乱毒素依赖性 ADP 核糖基化发现，大鼠基底神经节含有非常高水平的 G(salpha)-样蛋白；然而，它与其他脑区的 G(s)不同。此外，原位杂交和 Northern blot 研究表明，纹状体含有极低水平的 G(salpha)mRNA。G(olf)是最近从嗅觉感觉神经元中克隆出来的一种 G 蛋白，也可以刺激腺苷酸环化酶。我们现在已经在纹状体、伏隔核和嗅结节中发现了高水平的 G(olf)mRNA 表达。Northern blot 分析表明，在纹状体中，G(olf)转录本的丰度大约是 G(salpha)转录本的 10 倍。因此，G(olf)不是嗅觉神经元特异性 G 蛋白。它也是基底神经节中的主要刺激 G 蛋白，在那里它可能将 D1 多巴胺受体偶联到腺苷酸环化酶。
