Sharma K, Fabre E, Tekotte H, Hurt E C, Tollervey D
European Molecular Biology Laboratory, Heidelberg, Germany.
Mol Cell Biol. 1996 Jan;16(1):294-301. doi: 10.1128/MCB.16.1.294.
We have screened nucleoporin mutants for the inhibition of tRNA splicing, which has previously been proposed to be coupled to transport. Strains mutant for Nup49p or Nup116p, or genetically depleted of Nup145p, strongly accumulated unspliced pre-tRNAs. Splicing was inhibited for all 10 families of intron-containing pre-tRNA, but no effects on 5' or 3' end processing were detected. Strains mutant for Nup133p or Nsp1p accumulated lower levels of several unspliced pre-tRNAs. In contrast, no accumulation of any pre-tRNA was observed in strains mutant for Nup1p, Nup85p, or Nup100p. Other RNA processing reactions tested, pre-rRNA processing, pre-mRNA splicing, and small nucleolar and small nuclear RNA synthesis, were not clearly affected for any nucleoporin mutant. These data provide evidence for a coupling between pre-tRNA splicing and nuclear-cytoplasmic transport. Mutation of NUP49, NUP116, or NUP145 has previously been shown to lead to nuclear poly(A)+ RNA accumulation, indicating that these nucleoporins play roles in the transport of more than one class of RNA.
我们筛选了核孔蛋白突变体，以寻找对tRNA剪接有抑制作用的突变体，此前有人提出tRNA剪接与转运相关。Nup49p或Nup116p的突变菌株，或Nup145p基因缺失的菌株，强烈积累未剪接的前体tRNA。含内含子的前体tRNA的所有10个家族的剪接均受到抑制，但未检测到对5'或3'末端加工的影响。Nup133p或Nsp1p的突变菌株积累的几种未剪接前体tRNA水平较低。相比之下，在Nup1p、Nup85p或Nup100p的突变菌株中未观察到任何前体tRNA的积累。测试的其他RNA加工反应，即前体rRNA加工、前体mRNA剪接以及小核仁RNA和小核RNA合成，对于任何核孔蛋白突变体均未受到明显影响。这些数据为前体tRNA剪接与核质转运之间的偶联提供了证据。先前已表明NUP49、NUP116或NUP145的突变会导致细胞核内聚腺苷酸加尾RNA积累，表明这些核孔蛋白在不止一类RNA的转运中发挥作用。
