Bailer S M, Siniossoglou S, Podtelejnikov A, Hellwig A, Mann M, Hurt E
University of Heidelberg, Biochemie-Zentrum Heidelberg (BZH), Germany.
EMBO J. 1998 Feb 16;17(4):1107-19. doi: 10.1093/emboj/17.4.1107.
Nup116p and Nup100p are highly related yeast GLFG nucleoporins, but only Nup116p is stoichiometrically bound to Gle2p, a previously identified mRNA export factor. A short Gle2p-binding sequence within Nup116p (GLEBS; residues 110-166) is sufficient and necessary to anchor Gle2p at the nuclear pores, whereas the carboxy-terminal domain of Nup116p mediates its own nuclear pore complex (NPC) association. The GLEBS is evolutionarily conserved and found in rat/Xenopus Nup98 and an uncharacterized Caenorhabditis elegans ORF, but is absent from Nup100p. When the GLEBS is deleted from Nup116p, Gle2p dissociates from the nuclear envelope and clusters of herniated nuclear pores form. When the GLEBS is inserted into Nup100p, Nup100p-GLEBS complements both the thermosensitive and NPC-herniated phenotype of nup116- cells, and Gle2p is retargeted concomitantly to the NPCs. Thus, the in vivo function of Gle2p is strictly coupled to the short GLEBS within Nup116p which links this putative mRNA transport factor to the nuclear pores.
Nup116p和Nup100p是高度相关的酵母GLFG核孔蛋白,但只有Nup116p以化学计量的方式与Gle2p结合,Gle2p是先前鉴定出的一种mRNA输出因子。Nup116p内一段短的Gle2p结合序列(GLEBS;第110 - 166位氨基酸残基)对于将Gle2p锚定在核孔处是充分且必要的,而Nup116p的羧基末端结构域介导其自身与核孔复合体(NPC)的结合。GLEBS在进化上是保守的,在大鼠/非洲爪蟾的Nup98和一个未鉴定的秀丽隐杆线虫开放阅读框中发现,但在Nup100p中不存在。当从Nup116p中删除GLEBS时,Gle2p从核膜解离,并且形成核孔突出的簇。当将GLEBS插入Nup100p中时,Nup100p - GLEBS补充了nup116 - 细胞的温度敏感型和NPC突出型表型,并且Gle2p随之被重新定位到NPCs。因此,Gle2p的体内功能严格地与Nup116p内的短GLEBS相关联,该序列将这种假定的mRNA转运因子与核孔连接起来。