HIV Rev-dependent binding of SF2/ASF to the Rev response element: possible role in Rev-mediated inhibition of HIV RNA splicing.
Production of the structural and enzymatic proteins of type 1 human immunodeficiency virus (HIV-1) is controlled by the rev regulatory gene product. The 116-amino acid Rev protein acts by binding to the Rev response element (RRE), a complex RNA stem-loop structure located within the env gene of HIV. Rev exerts a series of posttranscriptional effects, including the inhibition of viral RNA splicing, the activation of nuclear export of incompletely spliced viral RNAs, and the enhancement of translation of RRE-containing RNAs. Our studies now demonstrate that at least one member of the SR family of splicing factors, SF2/ASF, specifically binds to a subregion of the RRE in vitro in a Rev-dependent manner. Furthermore, expression of high levels of SF2/ASF inhibits Rev function and impairs HIV replication in vivo. Both the in vitro binding of SF2/ASF to the Rev/RRE complex and the in vivo inhibition of Rev action by SF2/ASF are abrogated by mutation of the N-terminal RNA recognition motif but are not affected by mutation of the C-terminal arginine-serine-rich domain. These findings suggest that Rev inhibition of HIV splicing likely involves recruitment of the essential splicing factor SF2/ASF to the Rev/RRE complex. However, these inhibitory effects of Rev on viral RNA splicing are apparently overcome by augmenting the intracellular levels of SF2/ASF expression.
Powell
D M
DM
Gladstone Institute of Virology and Immunology, University of California, San Francisco 94141-9100, USA.
Amaral
M C
MC
Wu
J Y
JY
Maniatis
T
T
Greene
W C
WC
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002457:Cell Extracts; D002460:Cell Line; D002467:Cell Nucleus; D005347:Fibroblasts; D015694:Gene Products, rev / Q000235:genetics / Q000502:physiology*; D015497:HIV-1 / Q000235:genetics*; D000882:Haplorhini; D006367:HeLa Cells; D015368:Human T-lymphotropic virus 1 / Q000235:genetics; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D012326:RNA Splicing / Q000502:physiology*; D012367:RNA, Viral / Q000378:metabolism*; D016601:RNA-Binding Proteins; D000068103:Serine-Arginine Splicing Factors; D014779:Virus Replication; D054321:rev Gene Products, Human Immunodeficiency Virus
D002457:Cell Extracts; D015694:Gene Products, rev; D009687:Nuclear Proteins; D012367:RNA, Viral; D016601:RNA-Binding Proteins; D054321:rev Gene Products, Human Immunodeficiency Virus; D000068103:Serine-Arginine Splicing Factors