Bonnet-Mathonière B, Girard P M, Muriaux D, Paoletti J
Unité de Biochimie, URA 147 CNRS, Institut Gustave Roussy, Villejuif, France.
Eur J Biochem. 1996 May 15;238(1):129-35. doi: 10.1111/j.1432-1033.1996.0129q.x.
Short RNA species that encompass the psi domain of the retroviral genome spontaneously form dimers in vitro, and the retroviral nucleocapsid protein activates this dimerization in vitro. Addition of gag RNA sequences downstream of the 3' end of the psi domain decreases the level of spontaneous dimerization. Here, we report the effects of RNA length on dimerization in vitro, studied with RNA fragments from Moloney murine leukaemia virus that contain the psi domain and all or part of the gag sequence. Extension of the RNA leads to progressive inhibition of the in vitro dimerization process. Sequences located downstream of the 3' end of the psi domain seem to stabilize the monomeric structures. This stabilization participates in dimerization of the RNA sequences involved in the recognition of two RNA molecules. We studied the ability of nucleocapsid protein 10 to promote dimerization of such long RNA fragments, and found that the protein greatly enhances their dimerization in vitro. We propose that nucleocapsid protein 10 stimulates the overall dimerization process by reduction of the energy barrier that must be overcome to allow dimer formation. Our results show that dimerization of RNA form Moloney murine leukaemia virus in vitro is enhanced by nucleocapsid protein 10. This finding is in agreement with the involvement of the nucleocapsid protein in RNA dimerization in vivo.
包含逆转录病毒基因组ψ结构域的短RNA分子在体外会自发形成二聚体，并且逆转录病毒核衣壳蛋白在体外可激活这种二聚化作用。在ψ结构域3'端下游添加gag RNA序列会降低自发二聚化的水平。在此，我们报告了RNA长度对体外二聚化的影响，研究使用的是来自莫洛尼氏鼠白血病病毒的RNA片段，这些片段包含ψ结构域以及全部或部分gag序列。RNA的延长会导致体外二聚化过程逐渐受到抑制。位于ψ结构域3'端下游的序列似乎能稳定单体结构。这种稳定作用参与了涉及两个RNA分子识别的RNA序列的二聚化。我们研究了核衣壳蛋白10促进此类长RNA片段二聚化的能力，发现该蛋白在体外能极大地增强它们的二聚化。我们提出核衣壳蛋白10通过降低形成二聚体必须克服的能量屏障来刺激整体二聚化过程。我们的结果表明，核衣壳蛋白10增强了莫洛尼氏鼠白血病病毒RNA在体外的二聚化。这一发现与核衣壳蛋白在体内RNA二聚化中的作用相符。
