Changes in translational yield regulate tissue-specific expression of beta-glucuronidase.
Changes in translational yield regulate tissue-specific expression of beta-glucuronidase.
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翻译产量的变化调节β-葡萄糖醛酸酶的组织特异性表达。
DOI：
10.1073/pnas.84.24.9020
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发表时间：
1987
影响因子：
11.1
通讯作者：
Paigen,K
中科院分区：
文献类型：
--
作者：
Bracey,LT;Paigen,K
每个细胞的β-葡糖醛酸糖苷酶（GUS; β-D-葡糖醛酸糖苷葡糖醛酸水解酶，EC 3.2.1.31）分子的数量在小鼠组织中变化多达12倍。为了确定负责的调节机制，获得了B6.PAC-Gusn小鼠品系中6个组织的GUS蛋白合成（ks）和降解（kd）速率的估计值，该小鼠品系携带GUS基因的N单倍型。组织间酶水平的差异主要是由于酶合成速率的差异造成的;只有大脑的蛋白质降解速率存在显着差异。通常，组织含有每个细胞约2个GUS mRNA分子。GUS mRNA水平的差异，发现组织之间，但这些都不足以解释所观察到的KS差异。这表明组织在翻译产量方面不同，翻译产量被定义为GUS信息翻译效率与成功成熟为GUS四聚体的新产生多肽的分数的乘积。翻译产量的实验估计证实，这确实是GUS基因调控的组织差异的来源。GUS基因的B单倍型也证明了这一发现。特殊功能基因的差异调节一般是通过转录来实现的。相反，据报道，几个“管家”基因的差异调节产生于mRNA成熟和/或稳定性的变化。现在很明显，翻译产量，这是蛋白质合成的一个方面，也可以作为一个差异调节机制。
The number of beta-glucuronidase (GUS; beta-D-glucuronoside glucuronosohydrolase, EC 3.2.1.31) molecules per cell varies as much as 12-fold among mouse tissues. To identify the regulatory mechanisms responsible, estimates of the rates of GUS protein synthesis (ks) and degradation (kd) were obtained for six tissues in the B6.PAC-Gusn mouse strain, which carries the N haplotype of the GUS gene. Differences in enzyme levels among tissues were predominantly due to differences in rates of enzyme synthesis; only brain differed significantly in the rate of protein degradation. Typically, tissues contain about 2 molecules of GUS mRNA per cell. Differences in GUS mRNA levels were found among tissues, but these were not sufficient to account for observed differences in ks. This suggests that tissues differ in translational yield, which is defined as the product of the efficiency with which the GUS message is translated and the fraction of newly made polypeptides that are successfully matured into GUS tetramers. Experimental estimates of translational yield confirmed that this is indeed a source of tissue differences in GUS gene regulation. This finding also proved to be true of the B haplotype of the GUS gene. The differential regulation of special-function genes is, in general, effected transcriptionally. In contrast, the differential regulation of several "housekeeping" genes has been reported to arise from changes in mRNA maturation and/or stability. It is now apparent that translational yield, which is an aspect of protein synthesis, can also serve as a differential regulatory mechanism.