Three Residues in HIV-1 Matrix Contribute to Protease Inhibitor Susceptibility and Replication Capacity
Three Residues in HIV-1 Matrix Contribute to Protease Inhibitor Susceptibility and Replication Capacity
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DOI：
10.1128/aac.01228-10
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发表时间：
2011-03-01
影响因子：
4.9
通讯作者：
Pillay, Deenan
中科院分区：
文献类型：
--
作者：
Parry, Chris M.;Kolli, Madhavi;Pillay, Deenan
除了切割位点突变之外，关于Gag内影响HIV蛋白酶抑制剂敏感性的特定位置的数据很少。我们最近发现，gag的非切割位点突变，特别是在基质蛋白中，可以恢复复制能力，并进一步降低蛋白酶抑制剂药物敏感性时，与耐药（突变）蛋白酶共表达。研究了这种患者来源病毒的基质蛋白，以确定导致这种表型的特异性变化。基质中的三个氨基酸变化（R76 K、Y 79 F和T81 A）对复制能力以及药物敏感性有影响。将这三种变化引入野生型（WT）基质导致蛋白酶突变体病毒的复制能力增加至与突变体基质和部分衣壳蛋白内的所有变化所达到的水平相似的水平。野生型基质的成对变化导致蛋白酶突变体的复制能力增加（尽管小于所有三种变化）。在野生型病毒（含野生型蛋白酶）中，基质仅发生这三种变化，导致蛋白酶抑制剂50%有效浓度（EC 50）发生5- 7倍变化。个体变化对复制能力或药物敏感性没有太大的影响，表明这些位置之间存在相互作用，序列共变异分析也证实了这一点。分子模型预测，这三种突变中的每一种都会导致基质α-螺旋-4内氢键的丢失，从而导致假设该区域内的更多灵活性或改变的基质结构将解释我们的发现。
Other than cleavage site mutations, there is little data on specific positions within Gag that impact on HIV protease inhibitor susceptibility. We have recently shown that non-cleavage site mutations in gag, particularly within matrix protein can restore replication capacity and further reduce protease inhibitor drug susceptibility when coexpressed with a drug-resistant (mutant) protease. The matrix protein of this patient-derived virus was studied in order to identify specific changes responsible for this phenotype. Three amino acid changes in matrix (R76K, Y79F, and T81A) had an impact on replication capacity as well as drug susceptibility. Introduction of these three changes into wild-type (WT) matrix resulted in an increase in the replication capacity of the protease mutant virus to a level similar to that achieved by all the changes within the mutant matrix and part of the capsid protein. Pairs of changes to wild-type matrix led to an increased replication capacity of the protease mutant (although less than with all three changes). Having only these three changes to matrix in a wild-type virus (with wild-type protease) resulted in a 5- to 7-fold change in protease inhibitor 50% effective concentration (EC50). Individual changes did not have as great an effect on replication capacity or drug susceptibility, demonstrating an interaction between these positions, also confirmed by sequence covariation analysis. Molecular modeling predicts that each of the three mutations would result in a loss of hydrogen bonds within alpha-helix-4 of matrix, leading to the hypothesis that more flexibility within this region or altered matrix structure would account for our findings.