Bandobashi K, Maeda A, Teramoto N, Nagy N, Székely L, Taguchi H, Miyoshi I, Klein G, Klein E
Microbiology and Tumor Biology Center, Karolinska Institute, S-171 77 Stockholm, Sweden.
Virology. 2001 Sep 30;288(2):275-82. doi: 10.1006/viro.2001.1103.
We have studied the expression and the localization of the cellular proteins CBP/p300 and RBP-Jk in in vitro EBV-infected human B lymphocytes in relation to the EBNA-2 and EBNA-5 proteins. We found that the level of CBP/p300 was elevated drastically by EBV infection and also after activation by CD40 ligation. Thus the increase in CBP/p300 expression in the EBV-infected cells is related to the virus-induced activation and proliferation of the cells. EBNA-2 and RBP-Jk colocalized in the nucleoplasm, which is in accordance with their functional interaction. We confirmed earlier reports about the presence and colocalization of EBNA-5 and CBP in the nuclear POD bodies. On the other hand, neither EBNA-2 nor p300 was detected in the PODs. The expression of these two proteins overlapped in some distinct dots of the nucleoplasm. Taken together, the different patterns of CBP and p300 expression and their different localization in relation to the PML bodies and two EBV-encoded proteins in the B cells may provide some clue to their distinct functional roles.
我们研究了细胞蛋白CBP/p300和RBP-Jk在体外感染EBV的人B淋巴细胞中的表达及定位，以及它们与EBNA-2和EBNA-5蛋白的关系。我们发现，EBV感染以及CD40配体激活后，CBP/p300的水平急剧升高。因此，EBV感染细胞中CBP/p300表达的增加与病毒诱导的细胞激活和增殖有关。EBNA-2和RBP-Jk共定位于核质中，这与其功能相互作用一致。我们证实了先前关于EBNA-5和CBP在核POD小体中的存在及共定位的报道。另一方面，在POD小体中未检测到EBNA-2和p300。这两种蛋白的表达在核质的一些离散点上重叠。综上所述，CBP和p300不同的表达模式及其在B细胞中相对于PML小体和两种EBV编码蛋白的不同定位，可能为它们不同的功能作用提供一些线索。
