Minichromosome maintenance 2 bound with retroviral Gp70 is localized to cytoplasm and enhances DNA-damage-induced apoptosis.
Minichromosome maintenance 2 bound with retroviral Gp70 is localized to cytoplasm and enhances DNA-damage-induced apoptosis.
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DOI：
10.1371/journal.pone.0040129
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发表时间：
2012
期刊：
影响因子：
3.7
通讯作者：
Kitagawa M
中科院分区：
文献类型：
--
作者：
Abe S;Kurata M;Suzuki S;Yamamoto K;Aisaki K;Kanno J;Kitagawa M
病毒蛋白与宿主细胞蛋白的相互作用引起细胞信号转导通路的激活，可能导致病毒致病和细胞生物学事件的发生。由DNA损伤诱导的细胞凋亡信号可被Friend白血病病毒(Flv)显著上调，但其促进细胞凋亡和宿主特异性的机制尚不清楚。在这里，我们发现C3H小鼠来源的造血细胞最初表达的微小染色体维持(MCM)2蛋白水平高于BALB/c-或C57BL/6-分化细胞，并且在存在Flv包膜蛋白gp70的情况下，在阿霉素诱导的DNA损伤后经历更频繁的凋亡。即使在BALB/c来源的3T3细胞中，gp70/Mcm2双基因转染也能诱导阿霉素诱导的细胞凋亡。用MCM2的各种缺失突变体进行免疫沉淀分析表明，gp70与MCM2的核定位信号(NLS)1(氨基酸18-24)结合，干扰NLS2(氨基酸132-152)的功能，并抑制MCM2的正常核输入。细胞质MCM2降低蛋白磷酸酶2A(PP2A)的活性，导致DNA依赖的蛋白激酶(DNA-PK)的过度磷酸化。磷酸化的DNA-PK显示了磷酸化P53的激酶活性升高，从而上调了P53依赖的细胞凋亡。在MCM2的C末端部分(氨基酸703-904)发现了一个促进细胞凋亡的结构域。此外，同时使用FLV和阿霉素治疗可延长携带高表达MCM2的8047白血病细胞的SCID小鼠的存活时间。因此，根据其亚细胞定位的不同，MCM2发挥着不同的作用。如前所述，它参与了细胞核中的DNA复制，并促进了细胞质中的凋亡。
The interaction of viral proteins with host-cellular proteins elicits the activation of cellular signal transduction pathways and possibly leads to viral pathogenesis as well as cellular biological events. Apoptotic signals induced by DNA-damage are remarkably up-regulated by Friend leukemia virus (FLV) exclusively in C3H hosts; however, the mechanisms underlying the apoptosis enhancement and host-specificity are unknown. Here, we show that C3H mouse-derived hematopoietic cells originally express higher levels of the minichromosome maintenance (MCM) 2 protein than BALB/c- or C57BL/6-deriverd cells, and undergo more frequent apoptosis following doxorubicin-induced DNA-damage in the presence of the FLV envelope protein gp70. Dual transfection with gp70/Mcm2 reproduced doxorubicin-induced apoptosis even in BALB/c-derived 3T3 cells. Immunoprecipitation assays using various deletion mutants of MCM2 revealed that gp70 bound to the nuclear localization signal (NLS) 1 (amino acids 18–24) of MCM2, interfered with the function of NLS2 (amino acids 132–152), and suppressed the normal nuclear-import of MCM2. Cytoplasmic MCM2 reduced the activity of protein phosphatase 2A (PP2A) leading to the subsequent hyperphosphorylation of DNA-dependent protein kinase (DNA-PK). Phosphorylated DNA-PK exhibited elevated kinase activity to phosphorylate P53, thereby up-regulating p53-dependent apoptosis. An apoptosis-enhancing domain was identified in the C-terminal portion (amino acids 703–904) of MCM2. Furthermore, simultaneous treatment with FLV and doxorubicin extended the survival of SCID mice bearing 8047 leukemia cells expressing high levels of MCM2. Thus, depending on its subcellular localization, MCM2 plays different roles. It participates in DNA replication in the nucleus as shown previously, and enhances apoptosis in the cytoplasm.
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影响因子：
16
作者：
Chuang, Li-Chiou;Teixeira, Leonardo K.;Wohlschlegel, James A.;Henze, Martha;Yates, John R.;Mendez, Juan;Reed, Steven I.
通讯作者：
Reed, Steven I.
影响因子：
24.5
作者：
Going, JJ;Keith, WN;Williams, GH
通讯作者：
Williams, GH
影响因子：
6.7
作者：
Adeyemi RO;Landry S;Davis ME;Weitzman MD;Pintel DJ
通讯作者：
Pintel DJ
影响因子：
4.4
作者：
Kanno, J;Aisaki, K;Nagao, T
通讯作者：
Nagao, T
影响因子：
2.7
作者：
Hasegawa, Maki;Kurata, Morito;Kitagawa, Masanobu
通讯作者：
Kitagawa, Masanobu