Loss of nucleolar localization of NAT10 promotes cell migration and invasion in hepatocellular carcinoma
Loss of nucleolar localization of NAT10 promotes cell migration and invasion in hepatocellular carcinoma
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NAT10核仁定位丧失促进肝细胞癌细胞迁移和侵袭
DOI：
10.1016/j.bbrc.2018.04.047
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发表时间：
2018-05-23
影响因子：
3.1
通讯作者：
Du, Xiaojuan
中科院分区：
文献类型：
--
作者：
Tan, Yuqin;Zheng, Jiaojiao;Du, Xiaojuan
NAT10是一种核仁乙酰转移酶，参与多种细胞过程，包括核糖体生物发生和DNA损伤应答。免疫组织化学染色显示，细胞质和膜上的NAT10与人类癌症组织的临床病理特征相关。然而，NAT10如何从核仁转移到细胞质和膜的机制尚不清楚。在此，我们获得了一个定位于细胞质和膜的NAT10缺失突变体。生物信息学分析表明，残基68 - 75和989 - 1018是NAT10的两个潜在核定位信号（NLS）。绿色荧光蛋白 - NAT10缺失突变体（Δ989 - 1018）主要转移到细胞质中，核仁中保留微弱信号，而绿色荧光蛋白 - NAT10（Δ68 - 75）仍留在核仁和核质中，这表明残基989 - 1018是主要的核仁定位信号（NuLS）。绿色荧光蛋白 - NAT10 - D3，其两个片段（残基68 - 75和989 - 1018）均缺失，完全从核仁中排除并转移到细胞质和膜。因此，NAT10完整的核仁定位信号应包括残基68 - 75和989 - 1018。细胞质和膜上的NAT10突变体（Flag - NAT10 - D3）在细胞质中与α - 微管蛋白共定位，在细胞膜上与整合素共定位。重要的是，Flag - NAT10 - D3促进α - 微管蛋白乙酰化并稳定微管。因此，Flag - NAT10 - D3促进肝细胞癌（HCC）细胞的迁移和侵袭。对肝细胞癌组织中NAT10免疫组织化学染色的统计分析表明，与核内NAT10相比，细胞质中的NAT10与更差的预后相关，而膜上的NAT10预示着患者最差的临床结果。因此，我们为细胞质和膜上的NAT10在肝细胞癌患者转移和预后中的作用提供了证据。（C）2018爱思唯尔公司。保留所有权利。
NAT10, a nucleolar acetyltransferase, participates in a variety of cellular processes including ribosome biogenesis and DNA damage response. Immunohistochemistry staining showed that cytoplasmic and membranous NAT10 is related to the clinical pathologic characteristics in human cancer tissues. However, the mechanism about how NAT10 translocates from the nucleolus to cytoplasm and membrane is unclear. Here, we obtain a NAT10 deletion mutant localizing in cytoplasm and membrane. Bioinformatics analysis showed that residues 68-75 and 989-1018 are two potential nuclear localization signals (NLS) of NAT10. GFP-NAT10 deletion mutant (Delta 989-1018) predominantly translocates into cytoplasm with faint signal retained in the nucleolus, while GFP-NAT10(Delta 68-75) still remains in the nucleolus and nucleoplasm, indicating residues 989-1018 is the main nucleolar localization signal (NuLS). GFP-NAT10-D3, with both fragments (residues 68-75 and 989-1018) deleted, completely excludes from the nucleolus and translocates to cytoplasm and membrane. Therefore, complete NuLSs of NAT10 should include residues 68-75 and 989-1018. The cytoplasmic and membranous NAT10 mutant (Flag-NAT10-D3) colocalizes with alpha-tubulin in cytoplasm and with integrin on cell membrane. Importantly, Flag-NAT10-D3 promotes alpha-tubulin acetylation and stabilizes microtubules. Consequently, Flag-NAT10-D3 promotes migration and invasion in hepatocellular carcinoma (HCC) cells. Statistical analysis of immunohistochemistry staining of NAT10 in HCC tissues demonstrates that the cytoplasmic NAT10 is correlated with poorer prognosis compared with nuclear NAT10, while the membranous NAT10 predicts the poorest clinical outcome of the patients. We thus provide the evidence for the function of cytoplasmic and membranous NAT10 in the metastasis and prognosis of HCC patients. (C) 2018 Elsevier Inc. All rights reserved.