DEPLETION OF SACCHAROMYCES-CEREVISIAE RIBOSOMAL PROTEIN-L16 CAUSES A DECREASE IN 60S RIBOSOMAL-SUBUNITS AND FORMATION OF HALF-MER POLYRIBOSOMES
DEPLETION OF SACCHAROMYCES-CEREVISIAE RIBOSOMAL PROTEIN-L16 CAUSES A DECREASE IN 60S RIBOSOMAL-SUBUNITS AND FORMATION OF HALF-MER POLYRIBOSOMES
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DOI：
10.1101/gad.2.2.160
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发表时间：
1988-02-01
影响因子：
10.5
通讯作者：
WOOLFORD, JL
中科院分区：
文献类型：
--
作者：
ROTENBERG, MO;MORITZ, M;WOOLFORD, JL
我们构建了含有编码60 S核糖体亚基蛋白L16的RPL 16 A或RPL 16 B基因的缺失-插入无效等位基因的酵母菌株，以确定L16在核糖体合成和功能中的作用。缺乏功能性RPL 16 A基因的菌株生长与野生型一样快，而含有RPL 16 B无效等位基因的菌株生长比野生型慢。使用RPL 16探针的RNA分析揭示了两种RPL 16基因都被转录，并且RPL 16 B转录物积累到RPL 16 A转录物水平的两倍。没有证据表明在任一突变体中RPL 16 mRNA积累水平发生剂量补偿。缺乏两个RPL 16基因的菌株显然是不可存活的，这表明L16是一种必需的酵母核糖体蛋白。将RPL 16基因的额外拷贝引入rpl 16 b突变体中恢复了野生型生长速率，表明两种形式的L16蛋白是可互换的。相对于40 S亚基，rp 116突变体在60 S核糖体亚基中是缺陷的。在缺乏足够的60 S亚基的情况下，43 S前起始复合物在半聚体多聚核糖体中积累。我们推测rpl 16突变体的缓慢生长表型是由蛋白质合成起始的扰动引起的。
We constructed yeast strains containing deletion-insertion null alleles of the RPL16A or RPL16B genes encoding the 60S ribosomal subunit protein L16 to determine the role of L16 in the synthesis and function of ribosomes. Strains lacking a functional RPL16A gene grow as rapidly as wild type, whereas those containing a null allele of RPL16B grow more slowly than wild type. RNA analysis using RPL16 probes revealed that both RPL16 genes are transcribed and that RPL16B transcripts accumulate to twice the level of RPL16A transcripts. No evidence was obtained for the occurrence of dosage compensation at the level of RPL16 mRNA accumulation in either mutant. Strains lacking both RPL16 genes are apparently inviable, demonstrating that L16 is an essential yeast ribosomal protein. Introduction of an extra copy of either RPL16 gene into rpl16b mutants restored wild-type growth rates, indicating that the two forms of the L16 protein are interchangeable. rpl16 mutants are deficient in 60S ribosomal subunits relative to 40S subunits. 43S preinitiation complexes accumulate in half-mer polyribosomes in the absence of sufficient 60S subunits. We postulate that the slow-growth phenotype of rpl16 mutants results from the perturbation of initiation of protein synthesis.