Mutations of nuclear localization signals in mNANOG generate dominant negative mutants  

作　　者：ZHANG Juan ZHANG XiaoFei PEI DuanQing 

机构地区：[1]Laboratory of Stem Cell Biology, Department of Biological Sciences & Biotechnology State Key Laboratory of Biomembrane and Membrane Biotechnology, Institutes of Biomedicine, School of Medicine, Tsinghua University, Beijing 100084, China [2]Stem Cell and Cancer Biology Group, Key Laboratory of Regenerative Biology, South China Institute for Stern Cell Biology and Regenerative Medicine, Guangzhou Institute of Biomedicine and Health, Chinese Academy of Sciences, Guangzhou 510663, China

出　　处：《Chinese Science Bulletin》2009年第8期1361-1368,共8页

基　　金：Supported by National Natural Science Foundation of China (Grant Nos.30725012,30630039 and 90813033);Knowledge Innovation Project of Chinese Academy of Sciences (Grant No.KSCX2-YW-R-48);Guangzhou Science and Technology Commission Foundation (Grant No.2008A1-E4011);National Key Basic Research and Development Program of China (Grant Nos.2006CB701504,2006CB943600,2007CB948002 and 2007CB947804)

摘　　要：Mouse NANOG plays a critical role in maintaining self-renewal and pluripotency of embryonic stem cells.Yet,the precise mechanism of how mNANOG functions is still less known.Here,we report that mouse NANOG has two nuclear localization signals(NLS,RKQKMR and RMKCKR) which are responsible for the nuclear localization and transcriptional activity in the conserved homeobox domain.NLS mutants of mouse NANOG generate 3 mutants that are localized throughout the cells and lose the transactivation function.We further prove that all three NLS mutants may interact with the wild-type mouse NANOG like NANOG dimerization itself and inhibit the wild-type mouse NANOG activity,acting as dominant negative mutants.The NLS mutants of mouse NANOG may also inhibit activity of oct4 promoter in pluripotent cells,indicating that the NLS mutants can affect the endogenous mouse NANOG function in vivo.These data suggest that the NLS mutants of mouse NANOG may be used as a tool to regulate NANOG activity in pluripotent cells.Mouse NANOG plays a critical role in maintaining self-renewal and pluripotency of embryonic stem cells. Yet, the precise mechanism of how mNANOG functions is still less known. Here, we report that mouse NANOG has two nuclear localization signals （NLS, RKQKMR and RMKCKR） which are respon- sible for the nuclear localization and transcriptional activity in the conserved homeobox domain. NLS mutants of mouse NANOG generate 3 mutants that are localized throughout the cells and lose the transactivation function. We further prove that all three NLS mutants may interact with the wild-type mouse NANOG like NANOG dimerization itself and inhibit the wild-type mouse NANOG activity, acting as dominant negative mutants. The NLS mutants of mouse NANOG may also inhibit activity of oct4 promoter in pluripotent cells, indicating that the NLS mutants can affect the endogenous mouse NANOG function in vivo. These data suggest that the NLS mutants of mouse NANOG may be used as a tool to regulate NANOG activity in pluripotent cells.

关 键 词：核定位信号 突变体 显性 NANOG 突变小鼠 胚胎干细胞 转录活性 职能作用 

分 类 号：Q26[生物学—细胞生物学] S511[农业科学—作物学]