A genetic code alteration is a phenotype diversity generator in the human pathogen Candida albicans.
A genetic code alteration is a phenotype diversity generator in the human pathogen Candida albicans.
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DOI：
10.1371/journal.pone.0000996
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发表时间：
2007-10-03
期刊：
影响因子：
3.7
通讯作者：
Santos MA
中科院分区：
文献类型：
--
作者：
Miranda I;Rocha R;Santos MC;Mateus DD;Moura GR;Carreto L;Santos MA
在原核生物和真核生物中发现遗传密码的改变和扩展，废除了冷冻和通用遗传密码的假设，并暴露了密码子和氨基酸分配的意外灵活性。现在很清楚，密码子同一性改变涉及有义和无义密码子，并且可以发生在具有复杂基因组和蛋白质组的生物体中。然而，其生物学功能、进化的分子机制和遗传密码改变的多样性在很大程度上仍然未知。在念珠菌属的各种物种中，亮氨酸CUG密码子被含有亮氨酸5′-CAG-3′反密码子（tRNACAG Ser）的独特丝氨酸tRNA解码为丝氨酸。我们正在使用这种密码子身份重新定义作为一个模型系统，以阐明遗传密码改变的演变。我们已经重建了念珠菌遗传密码改变的早期阶段，通过工程改造的tRNA，部分恢复丝氨酸CUG密码子的身份回到他们的标准亮氨酸的意义。这种遗传密码的操纵具有深远的细胞后果，因为它暴露了重要的形态变异，改变了基因表达，重新排列了核型，增加了细胞间的粘附和水解酶的分泌。我们的研究提供了第一个实验证据，遗传密码改变作为高选择潜力的表型多样性的发电机的重要作用，并支持他们加快新的表型进化的假设。
The discovery of genetic code alterations and expansions in both prokaryotes and eukaryotes abolished the hypothesis of a frozen and universal genetic code and exposed unanticipated flexibility in codon and amino acid assignments. It is now clear that codon identity alterations involve sense and non-sense codons and can occur in organisms with complex genomes and proteomes. However, the biological functions, the molecular mechanisms of evolution and the diversity of genetic code alterations remain largely unknown. In various species of the genus Candida, the leucine CUG codon is decoded as serine by a unique serine tRNA that contains a leucine 5′-CAG-3′anticodon (tRNACAG Ser). We are using this codon identity redefinition as a model system to elucidate the evolution of genetic code alterations. We have reconstructed the early stages of the Candida genetic code alteration by engineering tRNAs that partially reverted the identity of serine CUG codons back to their standard leucine meaning. Such genetic code manipulation had profound cellular consequences as it exposed important morphological variation, altered gene expression, re-arranged the karyotype, increased cell-cell adhesion and secretion of hydrolytic enzymes. Our study provides the first experimental evidence for an important role of genetic code alterations as generators of phenotypic diversity of high selective potential and supports the hypothesis that they speed up evolution of new phenotypes.
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影响因子：
--
作者：
Gaur, NK;Smith, RL;Klotz, SA
通讯作者：
Klotz, SA
DOI：
10.1073/pnas.86.9.3252
发表时间：
1989-05-01
影响因子：
11.1
作者：
HARPER, DS;JAHN, CL
通讯作者：
JAHN, CL
影响因子：
3.2
作者：
CHU, WS;MAGEE, BB;MAGEE, PT
通讯作者：
MAGEE, PT
影响因子：
11.4
作者：
BREITSCHOPF, K;GROSS, HJ
通讯作者：
GROSS, HJ
影响因子：
11.4
作者：
Bennett, RJ;Johnson, AD
通讯作者：
Johnson, AD