Bradel-Tretheway Birgit G, Zhen Zhu, Dewhurst Stephen
Department of Microbiology and Immunology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 672, Rochester, NY 14642, USA.
J Virol Methods. 2003 Aug;111(2):145-56. doi: 10.1016/s0166-0934(03)00173-3.
Codon-optimization refers to the alteration of gene sequences, to make codon usage match the available tRNA pool within the cell/species of interest. Codon-optimization has emerged as a powerful tool to increase protein expression by genes from small RNA and DNA viruses, which commonly contain overlapping reading frames as well as structural elements that are embedded within coding regions; these features are not widespread among large DNA viruses. We therefore examined whether codon-optimization might influence protein expression from a herpesvirus gene. We focused on the U51 gene from human herpesviruses-6 and -7, which was cloned in both native and codon-optimized form, with an N-terminal HA epitope tag to allow protein detection. Codon-optimization was associated with a profound (10-100 fold) increase in U51 expression in human (293A, HSG, K562) or hamster (CHO) cell lines, suggesting this may represent a valuable tool to facilitate functional studies on recalcitrant herpesvirus genes. Finally, it is postulated that the suboptimal expression of native U51 may reflect a regulatory mechanism that controls viral gene expression.
密码子优化是指改变基因序列，使密码子的使用与目标细胞/物种中可用的tRNA库相匹配。密码子优化已成为一种强大的工具，可提高来自小RNA和DNA病毒的基因的蛋白质表达，这些病毒通常包含重叠阅读框以及嵌入编码区域内的结构元件；这些特征在大型DNA病毒中并不普遍。因此，我们研究了密码子优化是否会影响疱疹病毒基因的蛋白质表达。我们重点研究了人类疱疹病毒6型和7型的U51基因，该基因以天然形式和密码子优化形式进行克隆，并带有N端HA表位标签以进行蛋白质检测。在人（293A、HSG、K562）或仓鼠（CHO）细胞系中，密码子优化与U51表达的显著（10-100倍）增加相关，这表明这可能是促进对难治性疱疹病毒基因进行功能研究的有价值工具。最后，推测天然U51的次优表达可能反映了一种控制病毒基因表达的调节机制。
