Species-specific elements in the large T-antigen J domain are required for cellular transformation and DNA replication by simian virus 40
Species-specific elements in the large T-antigen J domain are required for cellular transformation and DNA replication by simian virus 40
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DOI：
10.1128/mcb.20.15.5749-5757.2000
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发表时间：
2000-08-01
影响因子：
5.3
通讯作者：
Pipas, JM
中科院分区：
文献类型：
--
作者：
Sullivan, CS;Tremblay, JD;Pipas, JM
猴病毒40（SV 40）大T抗原的J结构域是有效的DNA复制和转化所必需的。尽管以前的报告表明异源系统中J结构域的混杂性，但本文提供的结果显示在SV 40大T抗原介导的活性中需要特异性J结构域序列。特别地，其中SV 40 T抗原J结构域被来自酵母Ydj 1 p或大肠杆菌DnaJ蛋白的结构域替换的嵌合T抗原构建体不能在BSC 40细胞中复制，并且不能转化REF 52细胞。然而，含有JC病毒J结构域的T抗原在这些测定中是功能性的，尽管其效率低于野生型。一些大T抗原嵌合体无法促进DNA复制并引发细胞转化并不是因为未能与hsc 70相互作用，因为含有DnaJ J结构域的非功能性嵌合体与hsc 70结合。然而，这种非功能性嵌合T抗原刺激hsc 70 ATP酶活性的能力降低，不能从p130中释放E2 F，表明细胞生长和DNA复制所需因子的转录激活可能受到损害。我们的数据表明，T-抗原J结构域窝藏在体内的病毒活动所需的物种特异性元素。
The J domain of simian virus 40 (SV40) large T antigen is required for efficient DNA replication and transformation. Despite previous reports demonstrating the promiscuity of J domains in heterologous systems, results presented here show the requirement for specific J-domain sequences in SV40 large-T-antigen-mediated activities. In particular, chimeric-T-antigen constructs in which the SV40 T-antigen J domain was replaced with that from the yeast Ydj1p or Escherichia coli DnaJ proteins failed to replicate in BSC40 cells and did not transform REF52 cells. However, T antigen containing the JC virus J domain was functional in these assays, although it was less efficient than the wild type. The inability of some large-T-antigen chimeras to promote DNA replication and elicit cellular transformation was not due to a failure to interact with hsc70, since a nonfunctional chimera, containing the DnaJ J domain, bound hsc70. However, this nonfunctional chimeric T antigen was reduced in its ability to stimulate hsc70 ATPase activity and unable to liberate E2F from p130, indicating that transcriptional activation of factors required for cell growth and DNA replication may be compromised. Our data suggest that the T-antigen J domain harbors species-specific elements required for viral activities in vivo.