Unique characteristics of HIV-1 Vif expression.
We examined the steady-state expression in cells of four accessory proteins of human immunodeficiency virus type 1 (HIV-1). For this purpose, a series of single gene expression vectors for these viral proteins were constructed and were monitored for their production by transfection. Among them, the expression level of Vif was found to be lowest in both the absence and presence of APOBEC3G. In addition, we noticed the presence of its truncated form, which was not observed for the other accessory proteins. When a subgenomic vector was used for transfection, authentic and several small forms of Vif were produced. By mutational analysis, these forms were demonstrated to be mutant Vif proteins translated from M8, M16 and M29. When a full-length molecular clone was used, the smaller versions of Vif were hardly observed. Functional analysis of these mutant Vif proteins showed that they are incapable of modulating viral infectivity. The results described above, i.e. the low steady-state expression and the presence of truncated forms, represent the unique characteristics of HIV-1 Vif.
Wang
Huaqing
H
Department of Microbiology, Harbin Medical University, Harbin 150086, People's Republic of China.
Sakurai
Akiko
A
Khamsri
Boonruang
B
Uchiyama
Tsuneo
T
Gu
Hongxi
H
Adachi
Akio
A
Fujita
Mikako
M
D000595:Amino Acid Sequence; D002460:Cell Line; D015967:Gene Expression Regulation, Viral / Q000502:physiology*; D016346:Gene Products, vif / Q000502:physiology*; D016341:Genes, vif / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D009154:Mutation; D054320:vif Gene Products, Human Immunodeficiency Virus
D016346:Gene Products, vif; D054320:vif Gene Products, Human Immunodeficiency Virus