SELECTION OF AUG INITIATION CODONS DIFFERS IN PLANTS AND ANIMALS
SELECTION OF AUG INITIATION CODONS DIFFERS IN PLANTS AND ANIMALS
复制标题
DOI：
10.1002/j.1460-2075.1987.tb04716.x
复制
发表时间：
1987-01-01
期刊：
影响因子：
11.4
通讯作者：
SCHEELE, GA
中科院分区：
文献类型：
--
作者：
LUTCKE, HA;CHOW, KC;SCHEELE, GA
使用合成mRNA在两种不同的体外翻译系统中研究了相对于AUG起始密码子的-3位核苷酸对蛋白质合成起始的影响。由 SP6 启动子指导的 cDNA 转录而来的 4 个 mRNA 是相同的，除了核苷酸 -3 处的突变之外。在每种情况下，mRNA 的翻译都会产生 Mr = 12,600 的单一蛋白质。相对翻译效率在网织红细胞裂解物系统中表现出层次结构（-3 位的 A、G、U 和 C 分别为 100%、85%、61% 和 38%），但在小麦胚芽系统中没有差异。差异性 mRNA 降解或多肽链延长被排除为网织红细胞裂解液中观察到的翻译差异的原因。 mRNA 竞争增加了网织红细胞裂解物中观察到的翻译效率差异，但在小麦胚芽中没有显示出影响。对 61 种植物和 209 种动物 mRNA 序列的分析揭示了 AUG 起始密码子周围共有序列之间的定性和定量差异。动物的共有序列是 CACCAUG，而植物的共有序列是 AACAAUGGC。结构和功能研究结果表明，植物和动物中选择 AUG 起始密码子的因素存在显着差异。图片
The influence of the nucleotide at position -3 relative to the AUG initiation codon on the initiation of protein synthesis was studied in two different in vitro translation systems using synthetic mRNAs. The four mRNAs, transcribed from cDNAs directed by an SP6 promoter, were identical except for mutations at nucleotide -3. In each case, translation of mRNAs produced a single protein of Mr = 12,600. Relative translational efficiencies showed a hierarchy in the reticulocyte lysate system (100, 85, 61 and 38% for A, G, U and C in position -3, respectively) but no differences in the wheat germ system. Differential mRNA degradation or polypeptide chain elongation were excluded as causes of the differences observed in translation in the reticulocyte lysate. mRNA competition increased the differences observed in translational efficiencies in reticulocyte lysate but showed no effect in wheat germ. Analysis of 61 plant and 209 animal mRNA sequences revealed qualitative and quantitative differences between the consensus sequences surrounding AUG initiation codons. Whereas the consensus sequence for animals was CACCAUG that for plants was AACAAUGGC. Both the structural and functional findings suggest that the factors which select AUG initiation codons in plants and animals differ significantly. Images