A novel cellular protein, p60, interacting with both herpes simplex virus 1 regulatory proteins ICP22 and ICP0 is modified in a cell-type-specific manner and is recruited to the nucleus after infection
A novel cellular protein, p60, interacting with both herpes simplex virus 1 regulatory proteins ICP22 and ICP0 is modified in a cell-type-specific manner and is recruited to the nucleus after infection
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DOI：
10.1128/jvi.73.5.3810-3817.1999
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发表时间：
1999-05-01
影响因子：
5.4
通讯作者：
Roizman, B
中科院分区：
文献类型：
--
作者：
Bruni, R;Fineschi, B;Roizman, B
单纯疱疹病毒1编码两种多功能调节蛋白，感染细胞蛋白22和0 (ICP22和ICP0)， ICP0是一种混杂的反激活子，而ICP22在体内是必需的，并且在啮齿动物或兔细胞系和原代人细胞株（限制性细胞）中有效地复制和表达晚期（γ(2)）基因亚群，但在HEp-2或Vero（许可）细胞中则不需要。我们报告了在酵母双杂交系统中鉴定出一种与ICP22相互作用的细胞蛋白p60，该蛋白（表观M-r为60,000）以前没有被描述过，也没有已知的基序，对p60的分析揭示如下。(i) p60结合了快速迁移、未加工的野生型ICP22和缺乏羧基末端24个氨基酸的ICP22，而不缺乏羧基末端40个氨基酸的ICP22，而先前鉴定的细胞蛋白p78 （R Bruni and B, Roizman， J, Virol, 72:8525-8531, 1998）结合了所有形式的ICP22。p60仅与ICP22的一种异构体相互作用，支持了单纯疱疹病毒蛋白的每一种异构体执行一种可能不同于其他异构体的特定功能的假设，（ii） p60也结合ICP0；ICP0的结合不依赖于ICP22， （iii） p60在未感染的兔皮肤细胞的细胞核和细胞质中都有定位。在感染野生型病毒的兔皮肤细胞中，p60被翻译后加工到更高的表观M-r，但没有重新分布，翻译后加工需要编码ICP22和U(L)13蛋白激酶的基因存在。（iv）在未感染的HEp-2细胞中，p60主要定位于细胞核。在感染野生型病毒后不久，p60与ICP0一起定位在离散的小核结构中，在感染后期，ICP0和p60都趋于分散，而p60的表观M-r没有变化。p60的定位与ICP22无关，但p60更倾向于定位在小核结构中，而在缺乏编码U(L)13或U(S)3蛋白激酶基因的突变体感染的细胞中分散较少。结果表明，p60的翻译后修饰是由ICP0（允许细胞）或ICP22和U(L)13蛋白激酶（限制性兔皮肤细胞）介导的，兔皮肤细胞的限制性表型可能与缺乏编码U(L)13或ICP22基因的突变体不能加工p60有关。
Herpes simplex virus 1 encodes two multifunctional regulatory proteins, infected-cell proteins 22 and 0 (ICP22 and ICP0), ICP0 is a promiscuous transactivator, whereas ICP22 is required in vivo and for efficient replication and expression of a subset of late (gamma(2)) genes in rodent or rabbit cell lines and in primary human cell strains (restrictive cells) but not in HEp-2 or Vero (permissive) cells. We report the identification in the yeast two-hybrid system of a cellular protein designated p60 that interacts with ICP22, This protein (apparent M-r of 60,000) has not been previously described and has no known motifs, Analyses of p60 revealed the following. (i) p60 bound fast-migrating, underprocessed wild-type ICP22 and ICP22 lacking the carboxyl-terminal 24 amino acids but not ICP22 lacking the carboxyl-terminal 40 amino acids, whereas the previously identified cellular protein p78 (R Bruni and B, Roizman, J, Virol, 72:8525-8531, 1998) bound all forms of ICP22. The interaction of p60 with only one isoform of ICP22 supports that hypothesis that each isoform of herpes simplex virus proteins performs a specific function that may be different from that of other isoforms, (ii) p60 also bound ICP0; the binding of ICP0 was independent of that of ICP22, (iii) p60 localized in uninfected rabbit skin cells in both nuclei and cytoplasm. In rabbit skin cells infected with wild-type virus, p60 was posttranslationally processed to a higher apparent M-r but was not redistributed, Posttranslational processing required the presence of the genes encoding ICP22 and U(L)13 protein kinase. (iv) In uninfected HEp-2 cells, p60 localized primarily in nuclei. Soon after infection with wild-type virus, the p60 localized In discrete small nuclear structures with ICP0, Late in infection, both ICP0 and p60 tended to disperse but p60 did not change in apparent M-r. The localization of p60 was independent of ICP22, but p60 tended to be more localized in small nuclear structures and less dispersed in cells infected with mutants lacking the genes encoding the U(L)13 or U(S)3 protein kinases, The results suggest that posttranslational modification of p60 is mediated either by ICP0 (permissive cells) or by ICP22 and U(L)13 protein kinase (restrictive rabbit skin cells) and that the restrictive phenotype of rabbit skin cells may be related to the failure to process p60 by mutants lacking the genes encoding U(L)13 or ICP22.