Subcellular localization of human immunodeficiency virus type 1 RNAs, Rev, and the splicing factor SC-35.
The HIV-1 protein Rev regulates the cytoplasmic levels of incompletely spliced HIV-1 mRNAs. The plasmid pSVc21, which contains a HIV-1 provirus, was introduced into COS cells by transient transfection. Simultaneous detection of HIV-1 RNAs and Rev proteins produced in transfected cells was then performed in order to determine the relative distribution of these two components. HIV-1 RNAs and the Rev protein localized to the same areas of the nucleoplasm, implying that these locations represent sites where Rev interacts with its target RNAs. Using a monoclonal antibody targeted to the splicing factor SC-35 it was demonstrated that the sites where HIV-1 mRNAs and Rev were detected often contained weak anti-SC-35 staining, whereas little RNA and Rev were found in strongly labeled SC-35-containing speckles. The same distribution of HIV-1 RNAs relative to SC-35 was also seen in transfected HeLa cells and in primary human lymphocytes infected with HIV-1 primary isolates. In addition, transiently expressed intron-containing beta-globin RNAs were shown to distribute to weak anti-SC-35 staining in a manner similar to that of HIV-1 RNAs. The findings suggest that Rev and HIV-1 RNAs interact at putative sites of mRNA transcription and splicing.
Bøe
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Department of Microbiology and Immunology, Gade Institute, Bergen High Technology Center, University of Bergen, Norway. Stig.Boe@rmf.ulb.no
Bjørndal
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Røsok
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Szilvay
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Kalland
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D000818:Animals; D000911:Antibodies, Monoclonal; D001665:Binding Sites; D019556:COS Cells; D002467:Cell Nucleus / Q000378:metabolism / Q000821:virology; D015694:Gene Products, rev / Q000276:immunology / Q000378:metabolism*; D005914:Globins / Q000235:genetics; D015497:HIV-1 / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007438:Introns; D009687:Nuclear Proteins / Q000276:immunology / Q000378:metabolism*; D012326:RNA Splicing; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012367:RNA, Viral / Q000235:genetics / Q000378:metabolism*; D012261:Ribonucleoproteins; D000068103:Serine-Arginine Splicing Factors; D013347:Subcellular Fractions; D014162:Transfection; D054321:rev Gene Products, Human Immunodeficiency Virus
D000911:Antibodies, Monoclonal; D015694:Gene Products, rev; D009687:Nuclear Proteins; D012333:RNA, Messenger; D012367:RNA, Viral; D012261:Ribonucleoproteins; D054321:rev Gene Products, Human Immunodeficiency Virus; C073288:SRSF2 protein, human; D000068103:Serine-Arginine Splicing Factors; D005914:Globins