Rosbash M, Harris P K, Woolford J L, Teem J L
Cell. 1981 Jun;24(3):679-86. doi: 10.1016/0092-8674(81)90094-5.
The levels of four ribosomal protein (rp) mRNAs in different mutant strains were determined by hydridization of radiolabeled cloned genes to RNA fractionated on CH3HgOH gels and transferred to DBM paper. Two ribosomal protein genes (rp 51 and rp 52) controlled by the locus RNA2 have dramatically decreased mRNA levels after a shift-up to the nonpermissive temperature in a strain carrying the rna2 mutation (ts368). Two ribosomal protein genes not controlled by the RNA2 locus and several control nonribosomal protein genes are relatively unaffected by the temperature shift in this strain. Other genes in the vicinity of one of the rna2-sensitive ribosomal protein genes (th rp 51 gene) are insensitive to the rna2 gene product, suggesting that all ribosomal protein genes do not occur in clusters and that the RNA2 gene product does not affect a large region of chromatin. In ts368 at the nonpermissive temperature, the concentration of higher molecular weight transcripts complementary to the rp 51 and the rp 52 plasmids is increased. Analysis of the rp 51 plasmid transcripts reveals that the temperature-induced higher molecular weight transcripts differ from the mature rp 51 mRNA by the presence of an intron. This observation and the kinetics with which the concentration of the various rp 51 transcripts change after a temperature shift suggest that the effect of rna2 may be at the level of processing of rp mRNA.
通过将放射性标记的克隆基因与在CH3HgOH凝胶上分级分离并转移到DBM纸上的RNA进行杂交，测定了不同突变菌株中四种核糖体蛋白（rp）mRNA的水平。在携带rna2突变（ts368）的菌株中，转移到非允许温度后，由RNA2位点控制的两个核糖体蛋白基因（rp 51和rp 52）的mRNA水平显著降低。两个不受RNA2位点控制的核糖体蛋白基因和几个对照非核糖体蛋白基因在该菌株中相对不受温度变化的影响。rna2敏感的核糖体蛋白基因之一（th rp 51基因）附近的其他基因对rna2基因产物不敏感，这表明并非所有核糖体蛋白基因都成簇存在，且RNA2基因产物不会影响大片染色质区域。在非允许温度下的ts368中，与rp 51和rp 52质粒互补的高分子量转录物浓度增加。对rp 51质粒转录物的分析表明，温度诱导的高分子量转录物与成熟的rp 51 mRNA的区别在于存在一个内含子。这一观察结果以及温度变化后各种rp 51转录物浓度变化的动力学表明，rna2的作用可能在rp mRNA的加工水平。
