Samuel C E, Brody M S
Department of Biological Sciences, University of California, Santa Barbara 93106.
Virology. 1990 May;176(1):106-13. doi: 10.1016/0042-6822(90)90235-j.
The effect of 2-aminopurine (2AP), an inhibitor of the RNA-dependent P1/eIF-2 protein kinase, on the expression of the reovirus serotype 1 Lang strain S1 and S4 genes in transfected simian COS cells was examined. In the absence of 2AP, the s4-encoded sigma 3 gene product was expressed about five times more efficiently than the s1-encoded sigma 1 gene product. When COS cells were treated with 2AP, the synthesis of the sigma 1 polypeptide was increased about fivefold compared to that in untreated cells even though s1 mRNA levels were not detectably altered. In contrast to the increased translational efficiency of the s1 mRNA observed in 2AP-treated cells, the translational efficiency of the s4 mRNA was not affected by 2AP treatment. However, the cytoplasmic accumulation of s4 mRNA was transiently decreased by 2AP treatment. These results demonstrate that the expression of the reovirus S1 and S4 genes in transient transfection assays is differentially affected by 2AP. Furthermore, when considered together with the prior observation that the reovirus s1 mRNA is a potent activator of the RNA-dependent protein kinase relative to the s4 mRNA which is a very poor activator, the results are consistent with the suggestion that the differential translational efficiency of the reovirus s1 and s4 mRNAs in vivo may be attributed in part to their differential ability to activate the P1/eIF-2 protein kinase.
研究了RNA依赖性P1/eIF-2蛋白激酶抑制剂2-氨基嘌呤（2AP）对转染的猴COS细胞中呼肠孤病毒1型Lang株S1和S4基因表达的影响。在没有2AP的情况下，由s4编码的σ3基因产物的表达效率比由s1编码的σ1基因产物高约五倍。当用2AP处理COS细胞时，尽管s1 mRNA水平没有明显改变，但与未处理的细胞相比，σ1多肽的合成增加了约五倍。与在2AP处理的细胞中观察到的s1 mRNA翻译效率增加相反，s4 mRNA的翻译效率不受2AP处理的影响。然而，2AP处理使s4 mRNA的细胞质积累暂时减少。这些结果表明，在瞬时转染试验中，呼肠孤病毒S1和S4基因的表达受到2AP的不同影响。此外，结合先前的观察结果，即呼肠孤病毒s1 mRNA相对于作为非常弱激活剂的s4 mRNA是RNA依赖性蛋白激酶的有效激活剂，这些结果与以下观点一致：呼肠孤病毒s1和s4 mRNA在体内的不同翻译效率可能部分归因于它们激活P1/eIF-2蛋白激酶的能力差异。
