Epstein-Barr virus nuclear protein EBNA3C residues critical for maintaining lymphoblastoid cell growth
Epstein-Barr virus nuclear protein EBNA3C residues critical for maintaining lymphoblastoid cell growth
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DOI：
10.1073/pnas.0813134106
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发表时间：
2009-03
期刊：
影响因子：
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通讯作者：
S. Maruo;Yi Wu;Taku Ito;T. Kanda;E. Kieff;K. Takada
中科院分区：
文献类型：
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作者：
S. Maruo;Yi Wu;Taku Ito;T. Kanda;E. Kieff;K. Takada
EB病毒（EBV）核抗原3C（EBNA 3C）对于原代人B淋巴细胞向淋巴母细胞系（LCL）的有效转化和LCL的持续生长至关重要。我们使用了一个反式互补试验的背景下，转化的LCL的EBV与条件EBNA 3C，以确定EBNA 3C氨基酸（aa）维持LCL生长所必需的。令人惊讶的是，我们发现大多数EBNA 3C aa是持续LCL生长所必需的。只有氨基酸507-515、516-620、637-675或676-727内残基缺失的EBNA 3C突变体维持完全LCL生长，氨基酸728-732或910-992内残基缺失的EBNA 3C突变体维持缓慢LCL生长。相比之下，EBNA 3C缺乏aa 180-231，其介导RBP-Jκ结合，并且是EBNA 3C通过RBP-Jκ消除EBNA 2诱导的转录所必需的，不能支持LCL生长。此外，在aa 180-231内的2个EBNA 3C丙氨酸取代突变体（其在废除EBNA 2介导的通过RBP-Jκ的转录中是野生型（wt））维持LCL生长，并且在aa 180-231内的2个丙氨酸取代突变体（其在废除EBNA 2介导的通过RBP-Jκ的转录中是无效的）不维持LCL生长。这表明EBNA 3C通过RBP-Jκ调节转录对维持LCL生长至关重要。其他几种EBNA 3C功能也对LCL生长至关重要，因为缺失氨基酸130-159、251-506或733-909内残基的EBNA 3C突变体通过RBP-Jκ和表达水平废除转录，但不维持LCL生长。
Epstein-Barr virus (EBV) nuclear antigen 3C (EBNA3C) is essential for efficient conversion of primary human B lymphocytes to lymphoblastoid cell lines (LCLs) and for continued LCL growth. We used a transcomplementation assay in the context of LCLs transformed by an EBV with a conditional EBNA3C to identify the EBNA3C amino acids (aa) necessary for maintaining LCL growth. Surprisingly, we found that most EBNA3C aa were essential for continued LCL growth. Only EBNA3C mutants deleted for residues within aa 507–515, 516–620, 637–675, or 676–727 maintained full LCL growth, and EBNA3C mutants deleted for residues within aa 728–732 or 910–992 maintained slow LCL growth. In contrast, EBNA3C lacking aa 180–231, which mediate RBP-Jκ association and are necessary for EBNA3C abrogation of EBNA2-induced transcription through RBP-Jκ, could not support LCL growth. Furthermore, 2 EBNA3C alanine substitution mutants within aa 180–231, which were wild-type (wt) in abrogating EBNA2-mediated transcription through RBP-Jκ, maintained LCL growth, and 2 alanine substitution mutants within aa 180–231, which were null in abrogating EBNA2-mediated transcription through RBP-Jκ, did not maintain LCL growth. This indicates that EBNA3C regulation of transcription through RBP-Jκ is critical to maintaining LCL growth. Several other EBNA3C functions also are critical for LCL growth, because EBNA3C mutants deleted for residues within aa 130–159, 251–506, or 733–909 were wt in abrogating transcription through RBP-Jκ and expression level, but did not maintain LCL growth.