Runkel L, Fischer M, Schaller H
Zentrum für Molekulare Biologie, Universität Heidelberg, Germany.
Virology. 1993 Dec;197(2):529-36. doi: 10.1006/viro.1993.1626.
A panel of mutants of the hepatitis B virus X gene (HBx) was constructed by oligonucleotide-directed insertion of two codons (Arg Pro) at 10- or 20-amino-acid intervals along the entire gene. These mutants were tested in transiently transfected HepG2 cells for their effects on HBx trans-activation of an AP1-CAT reporter plasmid. The effects of HBx mutations on the mRNA and protein stability were also determined. Our results reveal two separate internal domains of the HBx, one around amino acid residue 68 and the other between residues 110 and 139, that are necessary for its activity. Mutations in the amino terminus (to position 45), between the two necessary domains and in the extreme carboxyl terminal portion of HBx, have little or no effect on its activity.
通过寡核苷酸定向在整个乙型肝炎病毒X基因（HBx）上每隔10或20个氨基酸插入两个密码子（精氨酸 脯氨酸）构建了一组HBx突变体。这些突变体在瞬时转染的HepG2细胞中进行测试，以检测它们对AP1-CAT报告质粒的HBx反式激活作用。还确定了HBx突变对mRNA和蛋白质稳定性的影响。我们的结果揭示了HBx的两个独立的内部结构域，一个在氨基酸残基68附近，另一个在残基110和139之间，这两个结构域对其活性是必需的。HBx氨基末端（至第45位）、两个必需结构域之间以及极端羧基末端部分的突变对其活性几乎没有影响。
