Sang Lee Jong, Gyu Park Sang, Park Heonyong, Seol Wongi, Lee Sangwon, Kim Sunghoon
National Creative Research Initiatives Center for ARS Network, College of Pharmacy, Seoul National University, Shinlim-Dong, Kwanak-Ku, Seoul, 157-742, Korea.
Biochem Biophys Res Commun. 2002 Feb 15;291(1):158-64. doi: 10.1006/bbrc.2002.6398.
Aminoacyl-tRNA synthetases (ARSs) ligate amino acids to their cognate tRNAs. It has been suggested that mammalian ARSs are linked to the EF-1 complex for efficient channeling of aminoacyl tRNAs to ribosome. Here we systemically investigated possible interactions between human ARSs and the subunits of EF-1 (alpha, beta, gamma, and delta) using a yeast two-hybrid assay. Among the 80 tested pairs, leucyl- and histidyl-tRNA synthetases were found to make strong and specific interaction with the EF-1gamma and beta while glu-proly-, glutaminyl-, alanyl-, aspartyl-, lysyl-, phenylalanyl-, glycyl-, and tryptophanyl-tRNA synthetases showed moderate interactions with the different EF-1 subunits. The interactions of leucyl- and histidyl-tRNA synthetase with the EF-1 complex were confirmed by immunoprecipitation and in vitro pull-down experiments. Interestingly, the aminoacylation activities of these two enzymes, but not other ARSs, were stimulated by the cofactor of EF-1, GTP. These data suggest that a systematic interaction network may exist between mammalian ARSs and EF-1 subunits probably to enhance the efficiency of in vivo protein synthesis.
氨酰 - tRNA合成酶（ARSs）将氨基酸连接到其对应的tRNA上。有人提出，哺乳动物的ARSs与EF - 1复合物相连，以便将氨酰tRNA高效地输送到核糖体。在这里，我们使用酵母双杂交试验系统地研究了人类ARSs与EF - 1的亚基（α、β、γ和δ）之间可能的相互作用。在80对测试组合中，发现亮氨酰 - 和组氨酰 - tRNA合成酶与EF - 1γ和β有强烈且特异性的相互作用，而谷氨酰胺 - 脯氨酰 -、谷氨酰胺 -、丙氨酰 -、天冬氨酰 -、赖氨酰 -、苯丙氨酰 -、甘氨酰 - 和色氨酰 - tRNA合成酶与不同的EF - 1亚基表现出中等程度的相互作用。亮氨酰 - 和组氨酰 - tRNA合成酶与EF - 1复合物的相互作用通过免疫沉淀和体外下拉实验得到证实。有趣的是，这两种酶（而非其他ARSs）的氨酰化活性受到EF - 1的辅因子GTP的刺激。这些数据表明，哺乳动物ARSs与EF - 1亚基之间可能存在一个系统的相互作用网络，可能是为了提高体内蛋白质合成的效率。
