Nakayama Naomi, Kato Hiroaki, Sakashita Gyosuke, Nariai Yuko, Nakayama Kentaro, Kyo Satoru, Urano Takeshi
Department of Biochemistry, Shimane University School of Medicine, Izumo 693-8501, Japan.
Department of Obstetrics and Gynecology, Shimane University School of Medicine, Izumo 693-8501, Japan.
Arch Biochem Biophys. 2016 Sep 15;606:10-5. doi: 10.1016/j.abb.2016.07.007. Epub 2016 Jul 14.
Nucleus accumbens-associated protein 1 (NAC1) is a cancer-related transcription regulator protein that is also involved in the pluripotency and differentiation of embryonic stem cells. NAC1 is overexpressed in various carcinomas including ovarian, cervical, breast, and pancreatic carcinomas. NAC1 knock-down was previously shown to result in the apoptosis of ovarian cancer cell lines and to rescue their sensitivity to chemotherapy, suggesting that NAC1 may be a potential therapeutic target, but protein complex formation and the dynamics of intranuclear NAC1 in cancer cells remain poorly understood. In this study, analysis of HeLa cell lysates by fast protein liquid chromatography (FPLC) on a sizing column showed that the NAC1 peak corresponded to an apparent molecular mass of 300-500 kDa, which is larger than the estimated molecular mass (58 kDa) of the protein. Furthermore, live cell photobleaching analyses with green fluorescent protein (GFP)-fused NAC1 proteins revealed the intranuclear dynamics of NAC1. Collectively our results demonstrate that NAC1 forms a protein complex to function as a transcriptional regulator in cancer cells.
伏隔核相关蛋白1（NAC1）是一种与癌症相关的转录调节蛋白，也参与胚胎干细胞的多能性和分化。NAC1在包括卵巢癌、宫颈癌、乳腺癌和胰腺癌在内的各种癌症中均有过表达。先前研究表明，敲低NAC1会导致卵巢癌细胞系凋亡，并恢复其对化疗的敏感性，这表明NAC1可能是一个潜在的治疗靶点，但癌细胞中蛋白质复合物的形成以及核内NAC1的动态变化仍知之甚少。在本研究中，通过在分子筛柱上进行快速蛋白质液相色谱（FPLC）分析HeLa细胞裂解物，结果显示NAC1峰对应的表观分子量为300 - 500 kDa，大于该蛋白的估计分子量（58 kDa）。此外，对绿色荧光蛋白（GFP）融合的NAC1蛋白进行活细胞光漂白分析，揭示了NAC1在核内的动态变化。我们的研究结果共同表明，NAC1形成一种蛋白质复合物，在癌细胞中作为转录调节因子发挥作用。
