Milligan G, Mullaney I, McKenzie F R
Department of Biochemistry, University of Glasgow, Scotland, U.K.
Biochem Soc Symp. 1990;56:21-34.
Individual G-proteins are highly similar in primary sequence. It is thus pertinent to ask what degree of specificity of interaction each of these display with the various receptors and effector systems. Many of the identified G-proteins are co-expressed in a single tissue or cell. As the extreme C-terminus of the alpha-subunit of each G-protein appears to be a key domain for the interactions of receptors and G-proteins, we have generated a series of G-protein-selective anti-peptide antisera against this region and then have used these antisera to attempt to interfere with receptor-G-protein coupling. With this approach, we have demonstrated that delta-opioid receptor-mediated inhibition of adenylate cyclase in neuroblastoma x glioma (NG108-15) cell membranes is transduced specifically by Gi2 and in the same cell that alpha 2-adrenergic inhibition of Ca2+ currents is transduced by G0.
单个G蛋白在一级序列上高度相似。因此，很有必要询问这些G蛋白中的每一个与各种受体和效应系统相互作用的特异性程度如何。许多已鉴定的G蛋白在单个组织或细胞中共表达。由于每个G蛋白α亚基的极端C末端似乎是受体与G蛋白相互作用的关键结构域，我们针对该区域产生了一系列G蛋白选择性抗肽抗血清，然后使用这些抗血清试图干扰受体-G蛋白偶联。通过这种方法，我们证明了在神经母细胞瘤x胶质瘤（NG108-15）细胞膜中，δ-阿片受体介导的腺苷酸环化酶抑制作用是由Gi2特异性转导的，并且在同一细胞中，α2-肾上腺素能对Ca2+电流的抑制作用是由G0转导的。
