A Bidirectional SF2/ASF- and SRp40-Dependent Splicing Enhancer Regulates Human Immunodeficiency Virus Type 1 rev, env, vpu, and nef Gene Expression
AUTOR(ES)
Caputi, Massimo
FONTE
American Society for Microbiology
RESUMO
The integrated human immunodeficiency virus type 1 (HIV-1) genome is transcribed in a single pre-mRNA that is alternatively spliced into more than 40 mRNAs. We characterized a novel bidirectional exonic splicing enhancer (ESE) that regulates the expression of the HIV-1 env, vpu, rev, and nef mRNAs. The ESE is localized downstream of the vpu-, env-, and nef-specific 3′ splice site no. 5. SF2/ASF and SRp40 activate the ESE and are required for efficient 3′ splice site usage and binding of the U1 snRNP to the downstream 5′ splice site no. 4. U1 snRNP binding to the 5′ splice site no. 4 is required for splicing of the rev and nef mRNAs and to increase expression of the partially spliced env mRNA. Finally, our results indicate that this ESE is necessary for the recruitment of the U1 snRNP to the 5′ splice site no. 4, even when the 5′ splice site and the U1 snRNA have been mutated to obtain a perfect complementary match. The ESE characterized here is highly conserved in most viral subtypes.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=416506Documentos Relacionados
- CD4 down-modulation during infection of human T cells with human immunodeficiency virus type 1 involves independent activities of vpu, env, and nef.
- Diminished Production of Human Immunodeficiency Virus Type 1 in Astrocytes Results from Inefficient Translation of gag, env, and nef mRNAs despite Efficient Expression of Tat and Rev
- A novel human immunodeficiency virus type 1 protein, tev, shares sequences with tat, env, and rev proteins.
- atSRp30, one of two SF2/ASF-like proteins from Arabidopsis thaliana, regulates splicing of specific plant genes
- HIV Rev-dependent binding of SF2/ASF to the Rev response element: Possible role in Rev-mediated inhibition of HIV RNA splicing