Amino acid residues 88 and 89 in the central hydrophilic region of human immunodeficiency virus type 1 Vif are critical for viral infectivity by enhancing the steady-state expression of Vif
Amino acid residues 88 and 89 in the central hydrophilic region of human immunodeficiency virus type 1 Vif are critical for viral infectivity by enhancing the steady-state expression of Vif
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DOI：
10.1128/jvi.77.2.1626-1632.2003
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发表时间：
2003-01-01
影响因子：
5.4
通讯作者：
Adachi, A
中科院分区：
文献类型：
--
作者：
Fujita, M;Sakurai, A;Adachi, A
人类免疫缺陷病毒I型（HIV-1） Vif的中心存在一个由聚集的带电荷氨基酸组成的亲水区域。在这项研究中，通过广泛的缺失和替代分析，研究了这个中心亲水区域（(EWRKKR93)-W-88）在非受纳H9细胞中的病毒复制中的作用。共构建了31个突变体。单独删除E-88或W-89残基可消除病毒在H9细胞中的感染性，并削弱病毒在原代巨噬细胞培养中的复制。取代分析表明，中心区域的亲水性和电荷对Vif的功能影响不显著。在16个替换突变体中，3个用A残基替换E-88和W-89的突变体在H9细胞中没有生长。转染后，发现4个突变体（即2个缺失E-88或W-89的突变体；1个用a替代E-88和W-89的突变体；1个用a替代E-88、W-89和R-90的突变体）表达Vif的水平比野生型克隆低得多。因此，这些结果表明Vif的氨基酸残基88和89通过增强Vif的稳态表达对HIV-1在靶细胞中的复制至关重要。此外，E-88和W-89残基在自然存在的HIV-1现场分离株和实验室HIV-1株的Vif蛋白中被发现是非常保守的。
A hydrophilic region consisting of strikingly clustered charged amino acids is present at the center of human immunodeficiency virus type I (HIV-1) Vif. In this study, the role for this central hydrophilic region ((EWRKKR93)-W-88) in the virus replication in nonpermissive H9 cells was investigated by extensive deletion and substitution analysis. A total of 31 mutants were constructed. Deletion of the E-88 or W-89 residue alone abolished viral infectivity in H9 cells and impaired virus replication in primary macrophage cultures. Substitution analysis indicated that the hydrophilicity and charge of the central region are insignificant for the function of Vif. Of the 16 substitution mutants, 3 mutants with substitution of E-88 and W-89 with an A residue did not grow in H9 cells. Upon transfection, four mutants (i.e., two mutants with deletion of E-88 or W-89; a mutant with substitution of E-88 and W-89 with A; and a mutant with substitution of E-88, W-89, and R-90 with A) were found to express Vif at a very reduced level relative to that by the wild-type clone. These results have thus demonstrated that amino acid residues 88 and 89 of Vif are critical for the replication of HIV-1 in target cells by enhancing the steady-state expression of Vif. In addition, E-88 and W-89 residues were found to be extremely conserved among the Vif proteins of naturally occurring HIV-1 field isolates as well as those of laboratory HIV-1 strains.