Grant K R, Harnett M M, Milligan G, Harnett W
Department of Immunology, University of Strathclyde, Glasgow, U.K.
Biochem J. 1996 Dec 1;320 ( Pt 2)(Pt 2):459-66.
Heterotrimeric G-proteins have been found in eukaryotic cells, from yeast to humans, but have received little attention, to date, with respect to parasitic organisms. We now present the first report of the characterization of heterotrimeric G-proteins expressed in a filarial nematode, Acanthocheilonema viteae. Using a combination of (i) affinity labelling with [alpha-32P]GTP; (ii) ADP-ribosylation with cholera toxin and pertussis toxin; (iii) Western blotting with a panel of anti-G-protein antibodies; and (iv) reverse transcriptase-PCR with degenerate G-protein oligonucleotide primers followed by hybridization analysis using oligonucleotides specific for individual G-protein subunits, we demonstrate that adult A. viteae expresses homologues of the beta 1- and/or beta 2-like subunits and alpha-subunits of the Gs, G1, Gq and G12 subfamilies found in mammals. The role which these G-proteins may play in the biology of the organism is discussed.
异源三聚体G蛋白存在于从酵母到人类的真核细胞中,但迄今为止,在寄生生物方面很少受到关注。我们现在首次报道了在丝状线虫——旋盘尾丝虫中表达的异源三聚体G蛋白的特性。我们结合使用了以下方法:(i)用[α-32P]GTP进行亲和标记;(ii)用霍乱毒素和百日咳毒素进行ADP-核糖基化;(iii)用一组抗G蛋白抗体进行蛋白质印迹分析;(iv)用简并G蛋白寡核苷酸引物进行逆转录聚合酶链反应,随后使用针对单个G蛋白亚基的寡核苷酸进行杂交分析,结果表明旋盘尾丝虫成虫表达了在哺乳动物中发现的Gs、G1、Gq和G12亚家族的β1-和/或β2样亚基以及α亚基的同源物。本文还讨论了这些G蛋白在该生物体生物学中可能发挥的作用。