He Xiangjun, Zhang Qi, Liu Yujing, He Peiying
Central Laboratory, Peking University People's Hospital, 100044, Beijing, China.
Virus Genes. 2005 Aug;31(1):49-55. doi: 10.1007/s11262-005-2200-4.
Apoptin, a chicken anemia virus protein, was reported to induce tumor specific apoptosis, which was correlated with the nuclear localization of the protein in tumor cells. While in normal human cells, Apoptin was detected mainly in the cytoplasm and did not induce apoptosis. Using a recombinant adenovirus expressing Apoptin, we have found that Apoptin induced G(2)-M cell cycle arrest and chromatin condensation in cancer cells. Here we report that adenovirus mediated Apoptin expression also induces G(2)-M arrest in normal cells. In normal cells Apoptin is localized mainly in the cytoplasm but is also found in the nucleus of a subset of cells. Apoptin induces chromatin condensation not only when it is expressed in the nucleus but also when it is expressed in the cytoplasm. Our results indicate that Apoptin-induced chromatin condensation in the normal cells may not correlate with its nuclear localization and the mechanism of regulating the G(2)-M transition might be a target for Apoptin.
凋亡素是一种鸡贫血病毒蛋白，据报道它能诱导肿瘤特异性凋亡，这与该蛋白在肿瘤细胞中的核定位相关。而在正常人类细胞中，凋亡素主要在细胞质中被检测到，且不诱导凋亡。通过使用一种表达凋亡素的重组腺病毒，我们发现凋亡素在癌细胞中诱导G(2)-M期细胞周期阻滞和染色质浓缩。在此我们报道，腺病毒介导的凋亡素表达在正常细胞中也诱导G(2)-M期阻滞。在正常细胞中，凋亡素主要定位于细胞质，但也可在一部分细胞的细胞核中发现。凋亡素不仅在细胞核中表达时诱导染色质浓缩，在细胞质中表达时也会诱导。我们的结果表明，凋亡素在正常细胞中诱导的染色质浓缩可能与其核定位无关，且调节G(2)-M期转换的机制可能是凋亡素的作用靶点。
