THE YEAST SIS1-PROTEIN, A DNAJ HOMOLOG, IS REQUIRED FOR THE INITIATION OF TRANSLATION
THE YEAST SIS1-PROTEIN, A DNAJ HOMOLOG, IS REQUIRED FOR THE INITIATION OF TRANSLATION
复制标题
DOI：
10.1016/0092-8674(93)90646-8
复制
发表时间：
1993-06-18
期刊：
影响因子：
64.5
通讯作者：
ARNDT, KT
中科院分区：
文献类型：
--
作者：
ZHONG, T;ARNDT, KT
酿酒酵母SIS1基因是必需的，其编码的热休克蛋白与细菌的Dna J蛋白相似。在不允许的温度下，温度敏感型菌株迅速积累80S核糖体，并减少多聚体的数量。60S核糖体亚基的某些改变可以抑制SIS1菌株对温度敏感的表型，并防止80S核糖体的积累和在SIS1功能降低的情况下常见的多聚体的丢失。对SIS1蛋白的蔗糖梯度分析表明，SIS1的很大一部分与40S核糖体亚基和较小的多聚体有关。这些结果和其他结果表明，SIS1是正常启动翻译所必需的。由于DNAJ已被证明介导了几个蛋白质复合体的解离，因此SIS1在翻译启动中的需要可能是介导翻译机制中特定蛋白质复合体的解离。
The S. cerevisiae SIS1 gene is essential and encodes a heat shock protein with similarity to the bacterial DnaJ protein. At the nonpermissive temperature, temperature-sensitive sis1 strains rapidly accumulate 80S ribosomes and have decreased amounts of polysomes. Certain alterations in 60S ribosomal subunits can suppress the temperature-sensitive phenotype of sis1 strains and prevent the accumulation of 80S ribosomes and the loss of polysomes normally seen under conditions of reduced SIS1 function. Analysis of sucrose gradients for SIS1 protein shows that a large fraction of SIS1 is associated with 40S ribosomal subunits and the smaller polysomes. These and other results indicate that SIS1 is required for the normal initiation of translation. Because DnaJ has been shown to mediate the dissociation of several protein complexes, the requirement of SIS1 in the initiation of translation might be for mediating the dissociation of a specific protein complex of the translation machinery.