- 作者: Keith M. Borg Justin P. Favaro Salvatore J. Arrigo Michael Schmidt
- 作者服務機構: Department of Microbiology and Immunology, Medical University of South Carollna, Charleston, S.C., USA
- 中文摘要: --
- 英文摘要: The human immunodeficiency virus type-1 regulatoryprotein Rev is absolutely required for the production ofviral structural proteins. Splice sites have been seen tofunction as cis-acting repressor sequendes(CRS) andinhibit expression of the Rev-dependent RNAs. In orderto analyze the role of a splice donor in Rev dependence,the wild-type 5' splice donor of HIV-1 was mutated in thecontext of other gag sequences. Following transienttransfection, RNA expression by RT-PCR was analyzed.The unspliced RNA produced by the mutant constructstill required Rev for the cytoplasmic accumulation of theRNA. Despite deletion of the wild-type 5' splice donorand the tat splice acceptor was used. A cryptic splicedonor was identified by PCR and subsequent cloning ofthe spliced RNA. The cryptic site is 5/9 to the consensussequence and located immediately downstream of theinitiation codon (ATG)for Gag. Analysis of the RNA prod-uct containing the cryptic splice donor revealed that theRev was required for the cytoplasmic accumulation ofunspliced RNA, while spliced RNA was Rev independent.Transfection of a wild-type construct also demonstratedusage of the cryptic splice donor. These results indicatethat a cryptic splice donor can be activated when thewild-type splice donor is inactivated and that the crypticsplice donor may retain Rev regulation. The findings alsosuggest the potential for cryptic splice sites to serve asCRS in the determining the Rev dependence of viralRNAs.
- 中文關鍵字: --
- 英文關鍵字: HIV-1. Rev. Splicing. Cryptic splice donor