Culbertson M R, Underbrink K M, Fink G R
Genetics. 1980 Aug;95(4):833-53. doi: 10.1093/genetics/95.4.833.
Suppressors of ICR-induced mutations that exhibit behavior similar to bacterial frameshift suppressors have been identified in the yeast Saccharomyces cerevisiae. The yeast suppressors have been divided into two groups. One of these groups (Group II: SUF1, SUF3, SUF4, SUF5 and SUF6) appears to include a set of informational suppressors in which the vehicle of suppression is glycyl-tRNA. Some of the genetic properties of Group II suppressors are described in this communication.--Corevertants of the Group II frameshift mutations his4-519 and leu2-3 have been characterized to determine the spectrum of reversion events induced by the frameshift mutagen ICR-170. Seventy-three ICR-induced corevertants were analyzed. With the exception of one cerevertant, which carried an allele of SUF1, all carried alleles of SUF3 or SUF5. SUF1, SUF3, SUF4 and SUF6 were represented among spontaneous and UV-induced corevertants. In the course of these experiments one of the suppressors was mapped. SUF5, the probable structural gene for tRNAGLY1, is located between ade2 and ade9 on chromosome XV.--SUF1, SUF4 and SUF6 have novel properties and comprise a distinct subset of suppressors. Although these suppressors show no genetic linkage to each other, they share several common features including lethality in haploid pairwise combinations, reduced tRNAGLY3 isoacceptor activity and increased efficiency of suppression in strains carrying the cytoplasmically inherited [PSI] element. In addition, strains carrying SUF1, SUF4 or SUF6 are phenotypically unstable and give rise to mitotic Suf+ segments at high frequency. These segregants invariably contain a linked, second-site mutation that maps in or adjacent to the suppressor gene itself. Strains carrying any of these suppressors also give rise to mitotic segregants that exhibit enhanced efficiency of suppression; mutations responsible for this phenotype map at two loci, upf1 and upf2. These genes show no genetic linkage to any of the group II suppressors.--Methods that permit positive selection have been devised in order to examine large numbers of variants. The importance of these interacting mutants is underscored by their potential utility in studying suppressor function at the molecular level.
在酿酒酵母中已鉴定出与细菌移码抑制子行为相似的ICR诱导突变的抑制子。酵母抑制子已被分为两组。其中一组（第二组：SUF1、SUF3、SUF4、SUF5和SUF6）似乎包含一组信息抑制子，其中抑制载体是甘氨酰 - tRNA。本文描述了第二组抑制子的一些遗传特性。——对第二组移码突变his4 - 519和leu2 - 3的回复突变体进行了表征，以确定移码诱变剂ICR - 170诱导的回复事件谱。分析了73个ICR诱导的回复突变体。除了一个携带SUF1等位基因的回复突变体外，所有回复突变体都携带SUF3或SUF5的等位基因。SUF1、SUF3、SUF4和SUF6存在于自发和紫外线诱导的回复突变体中。在这些实验过程中，对其中一个抑制子进行了定位。tRNAGLY1的可能结构基因SUF5位于第十五号染色体上的ade2和ade9之间。——SUF1、SUF4和SUF6具有新特性，构成了一个独特 的抑制子亚组。尽管这些抑制子彼此之间没有遗传连锁关系，但它们具有几个共同特征，包括单倍体两两组合时的致死性、tRNAGLY3同工受体活性降低以及在携带细胞质遗传的[PSI]元件的菌株中抑制效率提高。此外，携带SUF1、SUF4或SUF6的菌株在表型上不稳定，会高频产生有丝分裂的Suf + 片段。这些分离株总是含有一个连锁的第二位点突变，该突变位于抑制基因本身内部或其附近。携带这些抑制子中任何一个的菌株也会产生抑制效率增强的有丝分裂分离株；导致这种表型的突变位于upf1和upf2这两个位点。这些基因与第二组抑制子中的任何一个都没有遗传连锁关系。——已经设计出允许正选择的方法来检测大量变体。这些相互作用的突变体在分子水平上研究抑制子功能的潜在效用突出了它们的重要性。
