新的Vif结合CBFβ及降解APOBEC3的重要功能区

发布时间：2019-06-12 17:50

【摘要】：人体免疫缺陷病毒I型(HIV-1)的感染因子Vif需要核心结合因子CBFβ去降解APOBEC3这一家族限制性因子。尽管对相关Vif最小功能结构域及在Vif-N末端的一些疏水性氨基酸的研究已经被证实是Vif结合与CBFβ因子尤为重要的点[1-3]，但是是否存在其他的功能区来调节他们的结合仍需要我们更深入的研究。在此，，我们通过构建一系列的单个点突变及多点突变的Vif蛋白并且检测这些突变的Vif蛋白抑制APOBEC3G（A3G）和APOBEC3F（A3F）的抗病毒活性的研究，已经确定了两个新的Vif结合CBFβ因子的重要功能区。我们的实验结果确定的新两个功能区84GxSIEW89和L102ADQLI107中存在着一些点突变包括G84A/SIEW86-89AAAA (84/86-89), E88A/W89A (88/89), G84A, W89A, L106S,和I107S，与CBFβ结合减弱而影响了Vif的功能。由于CBFβ因子能够促进Vif与Cul5因子的结合，所以这些Vif突变体也影响了Vif与Cul5的结合[1]。我们研究发现这些点突变的Vif仍然存在与ELOB，APOBEC3G及APOBEC3F结合能力，进一步证实这些Vif功能的缺失并不是由于点突变引起Vif蛋白的错误折叠或者是构象改变引起的。在我们的研究中发现，G84D和D104A这两个位点对Vif-Cul5的结合能力的影响要强于对Vif-CBFβ结合能力的影响，这就意味着这些位点主要影响了Vif与Cul5的结合，Vif与Cul5的结合可能会有助于Vif与CBFβ结合。这些新的位于Vif与CBFβ因子相互结合界面的确定为艾滋病抑制剂的研究提供新靶点。
[Abstract]:The infection factor Vif of the human immunodeficiency virus type I (HIV-1) requires a core binding factor CBF to degrade the family restriction factor of the APOBEC3. Although studies on the associated Vif minimum functional domain and some of the hydrophobic amino acids at the terminal of the VIif-N have proven to be a point[1-3] that is particularly important for the Vif binding to the CBF factor, there are other functional areas to adjust their binding and still require more in-depth research. In this regard, we have identified two new Vif binding CBF-factor important functional areas by building a series of single point mutations and multi-point mutational Vif proteins and detecting these mutated Vif proteins to inhibit the antiviral activity of the APOBEC3G (A3G) and the APOBEC3F (A3F). Some point mutations in the new two functional areas 84 GxSIEW89 and L102ADQLI107, as determined by our experimental results, include G84A/ SIEW86-89 AAAA (84/86-89), E88A/ W89A (88/89), G84A, W89A, L106S, and I107S, and the binding of CBF to the Vif function. These VIif mutants also affect the binding of Vif to Cul5 due to the ability of the CBF factor to promote the combination of Vif with the Cul5 factor[1]. We have found that the Vif mutations at these points still have the ability to bind to the ELOBs, APOBEC3G and APOBEC3F, and further demonstrate that the deletion of these Vif functions is not caused by a false fold of the VIif protein due to a point mutation or a conformational change. In our study, the effect of the two sites of G84D and D104A on the binding capacity of Vif-Cul5 is stronger than that of Vif-CBF, which means that these sites mainly affect the binding of Vif to Cul5, and the binding of Vif to Cul5 may contribute to the binding of Vif to CBF. These new identification of the interface between Vif and CBF are new targets for the study of AIDS inhibitors.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：R512.91

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