Zabetakis D
Center for Bio/Molecular Science and Engineering, US Naval Research Laboratory, Washington, DC 20375, USA.
Yeast. 2000 Sep 15;16(12):1147-59. doi: 10.1002/1097-0061(20000915)16:12<1147::AID-YEA610>3.0.CO;2-M.
The NSR1 gene product is involved in ribosomal RNA production and ribosome assembly in Saccharomyces cerevisiae. Yeast strains carrying a deletion of the NSR1 gene have a defect in rRNA processing, an aberrant ribosome profile and are sensitive to the drug paromomycin. This paper reports the isolation and characterization of spontaneous suppressors of the paromomycin sensitivity. Such suppressors could be isolated at very high frequency and do not exhibit straightforward single-gene inheritance patterns. The suppressors are not influenced by non-Mendelian factors such as psi or rho. Through a replacement of chromosomal rDNA with a plasmid rDNA system, I show that suppression of paromomycin sensitivity is mediated by rDNA. Swapping wild-type plasmid rDNA for chromosomal rDNA can reverse the suppression, but the effect does not appear to be due to amplification of rDNA or amplification of a pre-existing mutant rDNA copy.
NSR1基因产物参与酿酒酵母中的核糖体RNA生成和核糖体组装。携带NSR1基因缺失的酵母菌株在rRNA加工方面存在缺陷，核糖体图谱异常，并且对巴龙霉素药物敏感。本文报道了巴龙霉素敏感性自发抑制子的分离和特性。这种抑制子能够以非常高的频率分离得到，并且不表现出直接的单基因遗传模式。这些抑制子不受诸如psi或rho等非孟德尔因子的影响。通过用质粒rDNA系统替换染色体rDNA，我发现巴龙霉素敏感性的抑制是由rDNA介导的。用野生型质粒rDNA替换染色体rDNA可以逆转这种抑制作用，但这种效应似乎不是由于rDNA的扩增或预先存在的突变rDNA拷贝的扩增。
