Gerdes A M, Hørder M, Bonnevie-Nielsen V
Department of Clinical Chemistry, Odense University Hospital, Denmark.
Clin Exp Immunol. 1993 Jul;93(1):93-6. doi: 10.1111/j.1365-2249.1993.tb06502.x.
2,5AS is induced by interferon-alpha, -beta (IFN-alpha, -beta) and polymerizes adenosine triphosphate (ATP) into pppA (2'p5'A) oligomers, leading to inhibition of protein synthesis and virus growth. The gene coding for the IFN-alpha, -beta receptor is localized to chromosome 21. In trisomy 21 cells from patients with Down's syndrome a 50% increase in gene dosage is present for the genes on this chromosome. Corresponding increase of gene products has been shown for several of these genes, e.g. the IFN-alpha, -beta receptor molecules. Here, we show a direct proportionality between the number of IFN-alpha, -beta receptors and both the basal activity of 2,5AS and the sensitivity of this enzyme for IFN-alpha, -beta. The relative increase of 2,5AS activity (the reactivity) becomes reduced consistent with the increased basal 2,5AS activity in trisomy 21 cells compared with control cells.
2,5-寡腺苷酸合成酶（2,5AS）由α-干扰素、β-干扰素（IFN-α、IFN-β）诱导产生，并将三磷酸腺苷（ATP）聚合成pppA（2'p5'A）寡聚物，从而抑制蛋白质合成和病毒生长。编码IFN-α、IFN-β受体的基因定位于21号染色体。在唐氏综合征患者的21三体细胞中，该染色体上的基因剂量增加了50%。其中一些基因，如IFN-α、IFN-β受体分子，已显示出相应的基因产物增加。在此，我们展示了IFN-α、IFN-β受体数量与2,5AS的基础活性以及该酶对IFN-α、IFN-β的敏感性之间存在直接比例关系。与对照细胞相比，21三体细胞中2,5AS基础活性增加，2,5AS活性（反应性）的相对增加随之降低。
