Hopper A K, Traglia H M, Dunst R W
Department of Biological Chemistry, M. S. Hershey Medical Center, Pennsylvania State University, Hershey 17033.
J Cell Biol. 1990 Aug;111(2):309-21. doi: 10.1083/jcb.111.2.309.
The yeast RNA1 gene is required for RNA processing and nuclear transport of RNA. The rna1-1 mutation of this locus causes defects in pre-tRNA splicing, processing of the primary pre-rRNA transcript, production of mRNA and export of RNA from the nucleus to the cytosol. To understand how this gene product can pleiotropically affect these processes, we sought to determine the intracellular location of the RNA1 protein. As determined by indirect immunofluorescence localization and organelle fractionation, the RNA1 antigen is found exclusively or primarily in the cytoplasm. Only a tiny fraction of the endogenous protein could be localized to and functional in the nucleus. Furthermore, the RNA1 antigen does not localize differently under stress conditions. These findings suggest that the RNA1 protein is not directly involved in RNA processing but may modify nuclear proteins or otherwise transmit a signal from the cytosol to the nucleus or play a role in maintaining the integrity of the nucleus.
酵母RNA1基因是RNA加工和RNA核转运所必需的。该基因座的rna1 - 1突变导致前体tRNA剪接、初级前体rRNA转录本加工、mRNA产生以及RNA从细胞核输出到细胞质出现缺陷。为了了解该基因产物如何多效性地影响这些过程，我们试图确定RNA1蛋白在细胞内的定位。通过间接免疫荧光定位和细胞器分级分离确定，RNA1抗原仅在细胞质中发现，或主要存在于细胞质中。只有一小部分内源性蛋白可定位于细胞核并在细胞核中发挥功能。此外，在应激条件下，RNA1抗原的定位没有差异。这些发现表明，RNA1蛋白不直接参与RNA加工，但可能修饰核蛋白，或以其他方式将信号从细胞质传递到细胞核，或在维持细胞核完整性方面发挥作用。
