Potashkin J, Frendewey D
Cold Spring Harbor Laboratory, NY 11724.
EMBO J. 1990 Feb;9(2):525-34. doi: 10.1002/j.1460-2075.1990.tb08139.x.
A bank of temperature sensitive (ts-) mutants of Schizosaccharomyces pombe was screened for snRNA expression mutants using an oligodeoxynucleotide that recognizes U2 RNA. One mutant with a novel phenotype was identified that has reduced steady-state levels of the spliceosomal snRNAs U1, U2, U4, U5 and U6. In addition, the mutant exhibits a temperature-dependent accumulation of aberrant U2 and U4 transcripts elongated at their 3' end. The steady-state concentration of the RNA component of RNase P is also reduced in the mutant, whereas the amount of U3 RNA, 7SL RNA, tRNA, rRNA and mRNA are the same as wild-type. Pre-mRNA, pre-tRNA and U6 RNA precursor processing are impaired in the mutant. Genetic analysis demonstrates that the snRNA defects are tightly linked to the ts- growth defect and are recessive. We have named this mutant snm1 to indicate a defect in snRNA maintenance. The data on snm1 suggest that a single trans-acting factor is essential for the maintenance of steady-state levels of several snRNAs and for proper 3' end formation of U2 and U4 RNAs.
利用识别U2 RNA的寡聚脱氧核苷酸，对粟酒裂殖酵母的一组温度敏感（ts-）突变体进行筛选，以寻找snRNA表达突变体。鉴定出一个具有新表型的突变体，其剪接体snRNA U1、U2、U4、U5和U6的稳态水平降低。此外，该突变体在3'端延伸的异常U2和U4转录本呈现温度依赖性积累。该突变体中RNase P的RNA组分的稳态浓度也降低，而U3 RNA、7SL RNA、tRNA、rRNA和mRNA的量与野生型相同。该突变体中前体mRNA、前体tRNA和U6 RNA前体的加工受损。遗传分析表明，snRNA缺陷与ts-生长缺陷紧密连锁且为隐性。我们将该突变体命名为snm1，以表明其在snRNA维持方面存在缺陷。关于snm1的数据表明，单一的反式作用因子对于维持几种snRNA的稳态水平以及U2和U4 RNA的正确3'端形成至关重要。
