Lee A H, Lee H Y, Sung Y C
Department of Life Science, Pohang University of Science and Technology, Republic of Korea.
Virology. 1994 Oct;204(1):409-13. doi: 10.1006/viro.1994.1545.
Human foamy virus (HFV) comprises a complex genomic organization of gag, pol, env, and several nonstructural genes such as bel1, bel2, bel3, bet, beo, and bes located between env and 3' LTR. Among these viral nonstructural genes, bel1 appears to encode an essential transactivator of LTR-directed gene expression. To investigate the roles of the other nonstructural proteins for the viral replication, a series of proviral mutants were generated and tested for their in vitro replication. The mutations in the other than bel1 open reading frame did not show any significant effect on viral replication. The bel1 protein is the only essential transactivator for the LTR-directed transcription. To determine whether HFV has an essential post-transcriptional transactivator like the rev protein of human immunodeficiency virus type 1, or the rex protein of human T cell leukemia virus type 1, we investigated the bel1-independent expression of the HFV gag structural gene under the control of the heterologous simian virus 40 promoter. We demonstrated that the expression of the HFV gag structural gene does not require an essential post-transcriptional transactivator. Thus, it appears that the regulation of HFV gene expression is distinct from that of other human retroviruses.
人类泡沫病毒（HFV）具有复杂的基因组结构，包括gag、pol、env以及几个非结构基因，如位于env和3' LTR之间的bel1、bel2、bel3、bet、beo和bes。在这些病毒非结构基因中，bel1似乎编码一种LTR指导的基因表达所必需的反式激活因子。为了研究其他非结构蛋白在病毒复制中的作用，构建了一系列前病毒突变体并对其体外复制进行了检测。bel1开放阅读框以外的突变对病毒复制没有显示出任何显著影响。bel1蛋白是LTR指导转录的唯一必需反式激活因子。为了确定HFV是否具有像人类免疫缺陷病毒1型的rev蛋白或人类T细胞白血病病毒1型的rex蛋白那样的必需转录后反式激活因子，我们研究了在异源猿猴病毒40启动子控制下HFV gag结构基因的非bel1依赖性表达。我们证明HFV gag结构基因的表达不需要必需的转录后反式激活因子。因此，看来HFV基因表达的调控与其他人类逆转录病毒不同。
