Lamb R A, Lai C J
Virology. 1984 May;135(1):139-47. doi: 10.1016/0042-6822(84)90124-7.
Influenza virus gene 8 codes for two nonstructural proteins (NS1 and NS2) which are translated, respectively, from a colinear and an interrupted mRNA. To investigate the mechanism of transcription processing by splicing, cloned full-length NS DNA was inserted into the late region of an SV40 vector. In this manner, transcription of NS RNA from the recombinant initiates and terminates using SV40 control sequences. RNA mapping and sequence analysis showed that the RNA transcripts are processed to produce both the spliced and unspliced NS mRNAs in approximately equal abundance. The junction sequence of the spliced mRNA is identical to that of NS2 mRNA found in influenza virus-infected cells. In addition, another mRNA species was found to contain a chimera splice between SV40 and NS sequences. Both NS1 and NS2 polypeptides are produced in the recombinant-infected cells as predicted from sequence analysis. These studies establish that during influenza virus infections processing of the NS1 mRNA transcript undergoes a mechanism of splicing similar to that occurring with DNA-directed RNA transcription.
流感病毒基因8编码两种非结构蛋白（NS1和NS2），它们分别从共线性和间断的mRNA翻译而来。为了研究通过剪接进行转录加工的机制，将克隆的全长NS DNA插入到SV40载体的晚期区域。通过这种方式，重组体中NS RNA的转录利用SV40控制序列起始和终止。RNA图谱分析和序列分析表明，RNA转录本经加工后产生的剪接和未剪接的NS mRNA丰度大致相等。剪接mRNA的连接序列与流感病毒感染细胞中发现的NS2 mRNA的连接序列相同。此外，还发现另一种mRNA含有SV40和NS序列之间的嵌合剪接。如序列分析所预测的，重组感染细胞中产生了NS1和NS2两种多肽。这些研究表明，在流感病毒感染期间，NS1 mRNA转录本的加工过程经历了一种类似于DNA指导的RNA转录过程中发生的剪接机制。
