A nucleus-localization-deficient mutant serves as a dominant-negative inhibitor of gut-enriched Kruppel-like factor function.
A nucleus-localization-deficient mutant serves as a dominant-negative inhibitor of gut-enriched Kruppel-like factor function.
复制标题
核定位缺陷突变体可作为肠道富集 Kruppel 样因子功能的显性失活抑制剂。
DOI：
10.1006/bbrc.2001.4762
复制
发表时间：
2001
影响因子：
3.1
通讯作者：
Tseng,CC
中科院分区：
文献类型：
--
作者：
Shie,JL;Tseng,CC
癌细胞在许多方面与正常细胞不同，包括分化丧失和细胞增殖不受抑制。最近的研究表明，肠道富含的 Krüppel 样因子 (GKLF) 在结肠细胞生长的调节中发挥着重要作用。该实验室的研究表明，GKLF 蛋白主要在结肠癌细胞的细胞质中表达，而不是在细胞核中表达，这表明 GKLF 的核转位受损可能会导致癌症的形成。在本报告中，研究了含有 GKLF 推定核定位信号 (NLS)（PKRGRR；氨基酸 385-390）的区域。 KR 突变为 WT 对 GKLF 对 HT-29 细胞中细胞周期蛋白 D1 启动子活性和[3H]胸苷摄取的抑制特性没有影响，而 RR 突变为 GL 则完全消除了 GKLF 功能。其他突变分析表明，Arg390 是该区域内介导 GKLF 功能及其核定位的最关键部分。共转染Arg390突变体(RR/RS)完全抑制野生型GKLF功能，并且GFP-RR/RS GKLF融合蛋白未能转位至细胞核。这项研究的结果表明，Arg390 赋予 GKLF 的 NLS，并且核定位缺陷突变体充当 GKLF 功能的显性失活抑制剂。
Cancer cells differ from normal cells in many aspects, including loss of differentiation and uninhibited cell proliferation. Recent studies have suggested that gut-enriched Krüppel-like factor (GKLF) played an important role in the regulation of cell growth in the colon. Studies from this laboratory have shown that GKLF protein predominantly expressed in the cytoplasm but not the nucleus of colon cancer cells, suggesting that impaired nuclear translocation of GKLF might contribute to cancer formation. In this report, a region containing putative nuclear localization signal (NLS) of GKLF (PKRGRR; amino acids 385–390) was investigated. Mutation of KR to WT had no effect on the inhibitory properties of GKLF on cyclin D1 promoter activity and [3H]thymidine uptake in HT-29 cells, whereas mutation of RR to GL abolished GKLF function completely. Additional mutation analyses demonstrated that Arg390is the most critical moiety within this region that mediated GKLF function and its nucleus localization. Cotransfection of Arg390mutant (RR/RS) completely inhibited wild-type GKLF function, and GFP-RR/RS GKLF fusion proteins failed to translocate to the nucleus. The results from this study demonstrate that Arg390confers the NLS of GKLF and that the nucleus-localization-deficient mutant serves as dominant-negative inhibitor of GKLF function.