Stepek G, Houston K M, Goodridge H S, Devaney E, Harnett W
Department of Immunology, University of Strathclyde, Glasgow, G4 ONR.
Parasitology. 2004 Jan;128(Pt 1):91-8. doi: 10.1017/s0031182003004220.
Previous studies have shown that the secreted phosphorylcholine-containing glycoprotein of filarial nematodes, ES-62, is only present in the post-infective life-cycle stages, but that the mRNA is transcribed throughout the worm's life-cycle. The aim of this current study was to investigate whether the presence or absence of protein expression simply reflects differences in mRNA abundance. To this end, we investigated the relative abundance of ES-62 using TaqMan real time RT-PCR, in different life-cycle stages of 2 model filarial nematode parasites, Acanthocheilonema viteae and Brugia pahangi. For B. pahangi, microfilariae, infective larvae and adult worms were each found to have approximately similar levels of ES-62 mRNA. However, the corresponding stages of A. viteae differed greatly from each other with a pattern of increased mRNA production with maturation. As a rule A. viteae had higher levels of ES-62 mRNA than B. pahangi, and this was particularly noticeable in the adult stage where the difference was approximately 3500-fold higher. However, this significant difference in mRNA abundance was not reflected in the quantity of ES-62 protein secreted by the adult worms of each species, as A. viteae only secreted approximately 3 times as much ES-62 as B. pahangi. Thus, overall, the results obtained from this study indicate that ES-62 protein production does not solely reflect mRNA levels, and also suggest that the 2 nematodes may employ different mechanisms for regulating protein production.
先前的研究表明，丝虫线虫分泌的含磷酸胆碱糖蛋白ES-62仅存在于感染后的生命周期阶段，但其mRNA在整个蠕虫生命周期中都有转录。本研究的目的是调查蛋白质表达的有无是否仅仅反映了mRNA丰度的差异。为此，我们使用TaqMan实时逆转录聚合酶链反应（RT-PCR），研究了2种丝状线虫寄生虫模型——旋盘尾丝虫和马来布鲁线虫——不同生命周期阶段中ES-62的相对丰度。对于马来布鲁线虫，发现微丝蚴、感染性幼虫和成虫的ES-62 mRNA水平大致相似。然而，旋盘尾丝虫的相应阶段彼此差异很大，呈现出随着成熟mRNA产量增加的模式。通常，旋盘尾丝虫的ES-62 mRNA水平高于马来布鲁线虫，在成虫阶段尤为明显，差异约为3500倍。然而，这种mRNA丰度的显著差异并未反映在每个物种成虫分泌的ES-62蛋白数量上，因为旋盘尾丝虫分泌的ES-62仅约为马来布鲁线虫的3倍。因此，总体而言，本研究获得的结果表明，ES-62蛋白的产生并不完全反映mRNA水平，也表明这两种线虫可能采用不同的机制来调节蛋白质的产生。
