Pinney D F, Emerson S U
J Virol. 1982 Jun;42(3):897-904. doi: 10.1128/JVI.42.3.897-904.1982.
Wild-type Indiana virus transcribed four 11- to 14-nucleotide-long, 5' N-gene mRNA sequences in vitro. The amount of oligonucleotides synthesized relative to leader by wild-type virions varied inversely with the salt concentration of the transcription reaction. Reduced oligonucleotide synthesis by nucleocapsids at all salt concentrations tested and a comparison of the proteins remaining bound to the template of nucleocapsids and virions transcribed in different NaCl concentrations suggested that the matrix (M) protein regulates oligonucleotide synthesis. Examination of the transcription products synthesized in no NaCl and 0.144 M NaCl by an M-protein mutant and an increase in oligonucleotide synthesis by nucleocapsids when purified M-protein was added to transcription reactions confirmed M-protein's role in oligonucleotide synthesis. Wild-type virion mRNA synthesis was inhibited, and oligonucleotide synthesis was greater than leader synthesis at high virus concentrations. As the virus was diluted, inhibition of mRNA synthesis was relieved and oligonucleotide synthesis was reduced. The M-protein mutant tsG33 exhibited neither transcription inhibition at high virus concentrations nor the reciprocal synthesis of mRNA and the oligonucleotides seen with wild-type virions. These results are entirely consistent with the stop-start model of transcription and suggest a model for the control of transcription by M-protein.
野生型印第安纳病毒在体外转录出四条长度为11至14个核苷酸的5' N基因mRNA序列。野生型病毒体相对于前导序列合成的寡核苷酸量与转录反应的盐浓度呈反比。在所有测试的盐浓度下，核衣壳的寡核苷酸合成均减少，并且对在不同NaCl浓度下转录的核衣壳和病毒体模板上剩余结合蛋白的比较表明，基质（M）蛋白调节寡核苷酸合成。通过M蛋白突变体检测在无NaCl和0.144 M NaCl中合成的转录产物，以及当将纯化的M蛋白添加到转录反应中时核衣壳的寡核苷酸合成增加，证实了M蛋白在寡核苷酸合成中的作用。野生型病毒体mRNA合成受到抑制，并且在高病毒浓度下寡核苷酸合成大于前导序列合成。随着病毒被稀释，mRNA合成的抑制被解除，寡核苷酸合成减少。M蛋白突变体tsG33在高病毒浓度下既不表现出转录抑制，也不表现出野生型病毒体所具有的mRNA和寡核苷酸的相互合成。这些结果与转录的起止模型完全一致，并提出了一个M蛋白控制转录的模型。
