SUBNUCLEAR LOCALIZATION AND PHOSPHORYLATION OF EPSTEIN-BARR-VIRUS LATENT INFECTION NUCLEAR PROTEINS
SUBNUCLEAR LOCALIZATION AND PHOSPHORYLATION OF EPSTEIN-BARR-VIRUS LATENT INFECTION NUCLEAR PROTEINS
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DOI：
10.1016/0042-6822(90)90027-o
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发表时间：
1990-06-01
期刊：
影响因子：
3.7
通讯作者：
KIEFF, E
中科院分区：
文献类型：
--
作者：
PETTI, L;SAMPLE, C;KIEFF, E
EB病毒潜伏感染核蛋白（EBNA-1、EBNA-2、EBNA-3A、EBNA-3B、EBNA-3C或EBNA-LP）在维持潜伏感染或细胞生长转化中的功能仅被部分理解。在免疫荧光显微镜下使用对每种EBNA特异的抗体，EBNA-2、-3A和-3C定位于填充大部分细胞核的亚核颗粒，不包括核仁。EBNA-LP定位于少量离散的亚核颗粒，也不包括核仁。只有EBNA-1与中期染色体相关。一致地，在生化核分馏研究中，EBNA-1是主要的染色质相关EBNA。EBNA-1也不同于其他EBNAs的程度，其协会与核质，并在其缺乏核基质协会。EBNA-LP、-2、-3A和-3C与核基质相关，尽管它们也在核质中发现，并且在较小程度上在染色质组分中发现。代谢32 Pi标记的细胞，然后通过二维凝胶电泳显示，EBNA-LP可以分解成多个磷酸化的异构体。EBNA-2也被磷酸化，并通过等电聚焦检测到许多亚型。
Functions of the six Epstein-Barr virus latent infection nuclear proteins (EBNA-1,-2, -3A, -3B, -3C, or -LP) in maintaining latent infection or cell growth transformation are only partially understood. Using antibodies specific for each EBNA in immunofluorescence microscopy, EBNA-2, -3A, and -3C localized to subnuclear granules which fill much of the nucleus, excluding nucleoli. EBNA-LP localized to a smaller number of discrete subnuclear particles, also excluding nucleoli. Only EBNA-1 associated with metaphase chromosomes. Concordantly, in biochemical nuclear fractionation studies, EBNA-1 was the major chromatin-associated EBNA. EBNA-1 also differed from the other EBNAs in the extent of its association with the nucleoplasm and in its lack of nuclear matrix association. EBNA-LP, -2, -3A, and -3C were associated with the nuclear matrix, although they were also found in the nucleoplasm and to a lesser extent in the chromatin fractions. Metabolic 32Pi-labeling of cells followed by two-dimensional gel electrophoresis showed that EBNA-LP could be resolved into multiple phosphorylated isoforms. EBNA-2 was also phosphorylated and many isoforms were detected by isoelectric focusing.