POSTTRANSCRIPTIONAL REGULATION AND ASSEMBLY INTO RIBOSOMES OF A SACCHAROMYCES-CEREVISIAE RIBOSOMAL-PROTEIN - BETA-GALACTOSIDASE FUSION
POSTTRANSCRIPTIONAL REGULATION AND ASSEMBLY INTO RIBOSOMES OF A SACCHAROMYCES-CEREVISIAE RIBOSOMAL-PROTEIN - BETA-GALACTOSIDASE FUSION
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DOI：
10.1128/mcb.5.12.3436
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发表时间：
1985-01-01
影响因子：
5.3
通讯作者：
ROSBASH, M
中科院分区：
文献类型：
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作者：
GRITZ, L;ABOVICH, N;ROSBASH, M
为了研究核糖体蛋白基因的调控，我们构建了酿酒酵母RP 51 A基因的lacZ融合体，包含RP 51 A的前64个密码子。在缺乏完整RP 51 A基因的菌株中（细胞由于存在活性RP 51 B基因而存活），β-半乳糖苷酶活性比含有RP 51 A的菌株高10倍。RP 51 A-lacZ mRNA水平在两种菌株中相等，表明调控是转录后的。在不存在RP 51 A基因的情况下，融合蛋白主要是细胞质的，并且与多聚核糖体相关，而在存在RP 51 A的情况下，融合蛋白主要是细胞核的，并且没有与多聚核糖体相关。在融合基因的RP 51 A编码部分中进行缺失。最广泛缺失的基因，仅含有与lacZ融合的前7个RP 51 A密码子，产生高水平的β-在存在和不存在RP 51 A基因的情况下的半乳糖苷酶活性。在这两种情况下，很少或根本没有发现这种较短的融合蛋白与多聚核糖体。因此，一个（或多个）调控位点位于RP 51 A的蛋白质编码区。我们认为rp 51融合蛋白的转录后调控与蛋白质组装成核糖体有关。
To study the regulation of ribosomal protein genes, we constructed a lacZ fusion of the Saccharomyces cerevisiae RP51A gene, containing the first 64 codons of RP51A. In a strain lacking an intact RP51A gene (cells are viable due to the presence of an active RP51B gene), .beta.-galactosidase activity is 10-fold greater than in a strain containing RP51A. RP51A-lacZ mRNA levels are equal in the two strains, indicating that regulation is posttranscriptional. In the absence of the RP51A gene, the fusion protein is predominantly cytoplasmic and associated with polysomes, whereas in the presence of RP51A, the fusion protein is predominantly nuclear, and none is associated with polysomes. Deletions were made in the RP51A-coding portion of the fusion gene. The most extensively deleted gene, containing only the first seven RP51A codons fused to lacZ, produced a high level of .beta.-galactosidase activity in both the presence and the absence of the RP51A gene. In both cases, little or none of this shorter fusion protein was found associated with polysomes. Thus, a regulatory site (or sites) lies in the protein-coding region of RP51A. We suggest that posttranscriptional regulation of the rp51 fusion protein is related to assembly to the protein into ribosomes.