核定位信号及其分析策略  

Categories and Research Strategies of Nuclear Localization Signal

作　　者：赵元茵[1] 王元忠[1] 曹念[2] 周度金[1] 李渝萍[1] 

机构地区：[1]第三军医大学生物化学与分子生物学教研室,重庆400038 [2]第三军医大学学员旅三队,重庆400038

出　　处：《中国生物化学与分子生物学报》2009年第8期683-689,共7页Chinese Journal of Biochemistry and Molecular Biology

基　　金：国家自然科学基金(No.30671056);重庆市自然科学基金(No.2008BB5019);第三军医大学"回国人员启动基金"资助(No.2008002)~~

摘　　要：真核细胞核膜上的核孔复合体(nuclear pore complex,NPC)是细胞核内外进行物质交换的主要通道,分子量较小的化合物可自由通过NPC或采取被动扩散的方式进入细胞核,而分子量为50kD以上的蛋白质则只能通过主动转运进入细胞核.以这种方式进入细胞核的蛋白质必须在其氨基酸序列上拥有特殊的核定位信号(nuclear localization signal,NLS),以被相应的核转运蛋白(karyopherins)识别.核定位信号具有多样性,包括经典核定位信号(classical NLS,cNLS),内输蛋白β2识别的核定位信号(又称PY模体-NLS)和其它类型的NLS.每一类NLS具有相似的特征,但并不具有完全保守的氨基酸组成.不同的NLS,往往对应着各不相同的核输入机制.而对同一蛋白质来说,也可能同时拥有几个功能性的NLS.研究核定位信号一方面可以帮助揭示新的大分子物质核转运机制,另一方面也有助于发现一些蛋白质的新功能.本文对常见NLS的分类进行了总结,并介绍了两种常用的NLS预测软件及鉴定NLS的一般策略.The nuclear pore complex （NPC） is in charge of the exchange of macromolecules between the nuclei and the cytoplasm of eucaryotic cells. The small compounds can get into the nuclei through the NPC freely or by passive diffusion. However, those proteins whose molecular weights are larger than 50 kD can only get into nuclei by active transport. There must be one or more special signals in the amino acid sequences, socalled nuclear localization signals, which can be recognized by respective karyopherins, in those proteins. There are diverse sequences in NLSs, including classical NLS （cNLS）, PY-NLS, which can be recognized by importin β32, and some other NLSs. Though there are similar properties among the same family members of NLSs, there is no fully conserved amino acid sequence. Different NLSs often correspond to different mechanisms of nuclear transport, and also, couple of functional NLSs may exist in one certain protein. The studies on NLS help us not only reveal new nuclear transport mechanism of macromolecules, but also discover new functions of proteins. Categories of NLSs were summarized by the authors. Two common-used software employed in NLS prediction and the strategies used to identify NLS are also introduced in this review.

关 键 词：核转运机制 核定位信号 内输蛋白 

分 类 号：Q291[生物学—细胞生物学]