Abstract
The Rev protein of human immunodeficiency virus type 1 (HIV-1) facilitates the nuclear export of unspliced and partially spliced viral RNAs. In the absence of Rev, these intron-containing HIV-1 RNAs are retained in the nucleus. The basis for nuclear retention is unclear and is an important aspect of Rev regulation. Here we use in situ hybridization and digital imaging microscopy to examine the intranuclear distributions of intron-containing HIV RNAs and to determine their spatial relationships to intranuclear structures. HeLa cells were transfected with an HIV-1 expression vector, and viral transcripts were localized using oligonucleotide probes specific for the unspliced or spliced forms of a particular viral RNA. In the absence of Rev, the unspliced viral RNAs were predominantly nuclear and had two distinct distributions. First, a population of viral transcripts was distributed as approximately 10-20 intranuclear punctate signals. Actinomycin D chase experiments indicate that these signals represent nascent transcripts. A second, stable population of viral transcripts was dispersed throughout the nucleoplasm excluding nucleoli. Rev promoted the export of this stable population of viral RNAs to the cytoplasm in a time-dependent fashion. Significantly, the distributions of neither the nascent nor the stable populations of viral RNAs coincided with intranuclear speckles in which splicing factors are enriched. Using splice-junction-specific probes, splicing of human beta-globin pre-mRNA occurred cotranscriptionally, whereas splicing of HIV-1 pre-mRNA did not. Taken together, our results indicate that the nucleolus and intranuclear speckles are not involved in Rev regulation, and provide further evidence that efficient splicing signals are critical for cotranscriptional splicing.
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- Bartel D. P., Zapp M. L., Green M. R., Szostak J. W. HIV-1 Rev regulation involves recognition of non-Watson-Crick base pairs in viral RNA. Cell. 1991 Nov 1;67(3):529–536. doi: 10.1016/0092-8674(91)90527-6. [DOI] [PubMed] [Google Scholar]
- Baurén G., Wieslander L. Splicing of Balbiani ring 1 gene pre-mRNA occurs simultaneously with transcription. Cell. 1994 Jan 14;76(1):183–192. doi: 10.1016/0092-8674(94)90182-1. [DOI] [PubMed] [Google Scholar]
- Beyer A. L., Osheim Y. N. Splice site selection, rate of splicing, and alternative splicing on nascent transcripts. Genes Dev. 1988 Jun;2(6):754–765. doi: 10.1101/gad.2.6.754. [DOI] [PubMed] [Google Scholar]
- Bogerd H. P., Fridell R. A., Madore S., Cullen B. R. Identification of a novel cellular cofactor for the Rev/Rex class of retroviral regulatory proteins. Cell. 1995 Aug 11;82(3):485–494. doi: 10.1016/0092-8674(95)90437-9. [DOI] [PubMed] [Google Scholar]
- Carmo-Fonseca M., Tollervey D., Pepperkok R., Barabino S. M., Merdes A., Brunner C., Zamore P. D., Green M. R., Hurt E., Lamond A. I. Mammalian nuclei contain foci which are highly enriched in components of the pre-mRNA splicing machinery. EMBO J. 1991 Jan;10(1):195–206. doi: 10.1002/j.1460-2075.1991.tb07936.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Chang D. D., Sharp P. A. Regulation by HIV Rev depends upon recognition of splice sites. Cell. 1989 Dec 1;59(5):789–795. doi: 10.1016/0092-8674(89)90602-8. [DOI] [PubMed] [Google Scholar]
- Daly T. J., Cook K. S., Gray G. S., Maione T. E., Rusche J. R. Specific binding of HIV-1 recombinant Rev protein to the Rev-responsive element in vitro. Nature. 1989 Dec 14;342(6251):816–819. doi: 10.1038/342816a0. [DOI] [PubMed] [Google Scholar]
- Dayton A. I., Sodroski J. G., Rosen C. A., Goh W. C., Haseltine W. A. The trans-activator gene of the human T cell lymphotropic virus type III is required for replication. Cell. 1986 Mar 28;44(6):941–947. doi: 10.1016/0092-8674(86)90017-6. [DOI] [PubMed] [Google Scholar]
- Dayton E. T., Powell D. M., Dayton A. I. Functional analysis of CAR, the target sequence for the Rev protein of HIV-1. Science. 1989 Dec 22;246(4937):1625–1629. doi: 10.1126/science.2688093. [DOI] [PubMed] [Google Scholar]
- Emerman M., Vazeux R., Peden K. The rev gene product of the human immunodeficiency virus affects envelope-specific RNA localization. Cell. 1989 Jun 30;57(7):1155–1165. doi: 10.1016/0092-8674(89)90053-6. [DOI] [PubMed] [Google Scholar]
- Fakan S., Leser G., Martin T. E. Ultrastructural distribution of nuclear ribonucleoproteins as visualized by immunocytochemistry on thin sections. J Cell Biol. 1984 Jan;98(1):358–363. doi: 10.1083/jcb.98.1.358. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Feinberg M. B., Jarrett R. F., Aldovini A., Gallo R. C., Wong-Staal F. HTLV-III expression and production involve complex regulation at the levels of splicing and translation of viral RNA. Cell. 1986 Sep 12;46(6):807–817. doi: 10.1016/0092-8674(86)90062-0. [DOI] [PubMed] [Google Scholar]
- Felber B. K., Hadzopoulou-Cladaras M., Cladaras C., Copeland T., Pavlakis G. N. rev protein of human immunodeficiency virus type 1 affects the stability and transport of the viral mRNA. Proc Natl Acad Sci U S A. 1989 Mar;86(5):1495–1499. doi: 10.1073/pnas.86.5.1495. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Fritz C. C., Zapp M. L., Green M. R. A human nucleoporin-like protein that specifically interacts with HIV Rev. Nature. 1995 Aug 10;376(6540):530–533. doi: 10.1038/376530a0. [DOI] [PubMed] [Google Scholar]
- Hadzopoulou-Cladaras M., Felber B. K., Cladaras C., Athanassopoulos A., Tse A., Pavlakis G. N. The rev (trs/art) protein of human immunodeficiency virus type 1 affects viral mRNA and protein expression via a cis-acting sequence in the env region. J Virol. 1989 Mar;63(3):1265–1274. doi: 10.1128/jvi.63.3.1265-1274.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hammarskjöld M. L., Heimer J., Hammarskjöld B., Sangwan I., Albert L., Rekosh D. Regulation of human immunodeficiency virus env expression by the rev gene product. J Virol. 1989 May;63(5):1959–1966. doi: 10.1128/jvi.63.5.1959-1966.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Heaphy S., Dingwall C., Ernberg I., Gait M. J., Green S. M., Karn J., Lowe A. D., Singh M., Skinner M. A. HIV-1 regulator of virion expression (Rev) protein binds to an RNA stem-loop structure located within the Rev response element region. Cell. 1990 Feb 23;60(4):685–693. doi: 10.1016/0092-8674(90)90671-z. [DOI] [PubMed] [Google Scholar]
- Huang X. J., Hope T. J., Bond B. L., McDonald D., Grahl K., Parslow T. G. Minimal Rev-response element for type 1 human immunodeficiency virus. J Virol. 1991 Apr;65(4):2131–2134. doi: 10.1128/jvi.65.4.2131-2134.1991. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jackson D. A., Hassan A. B., Errington R. J., Cook P. R. Visualization of focal sites of transcription within human nuclei. EMBO J. 1993 Mar;12(3):1059–1065. doi: 10.1002/j.1460-2075.1993.tb05747.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kalland K. H., Szilvay A. M., Langhoff E., Haukenes G. Subcellular distribution of human immunodeficiency virus type 1 Rev and colocalization of Rev with RNA splicing factors in a speckled pattern in the nucleoplasm. J Virol. 1994 Mar;68(3):1475–1485. doi: 10.1128/jvi.68.3.1475-1485.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kjems J., Brown M., Chang D. D., Sharp P. A. Structural analysis of the interaction between the human immunodeficiency virus Rev protein and the Rev response element. Proc Natl Acad Sci U S A. 1991 Feb 1;88(3):683–687. doi: 10.1073/pnas.88.3.683. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kjems J., Frankel A. D., Sharp P. A. Specific regulation of mRNA splicing in vitro by a peptide from HIV-1 Rev. Cell. 1991 Oct 4;67(1):169–178. doi: 10.1016/0092-8674(91)90580-r. [DOI] [PubMed] [Google Scholar]
- LeMaire M. F., Thummel C. S. Splicing precedes polyadenylation during Drosophila E74A transcription. Mol Cell Biol. 1990 Nov;10(11):6059–6063. doi: 10.1128/mcb.10.11.6059. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Legrain P., Rosbash M. Some cis- and trans-acting mutants for splicing target pre-mRNA to the cytoplasm. Cell. 1989 May 19;57(4):573–583. doi: 10.1016/0092-8674(89)90127-x. [DOI] [PubMed] [Google Scholar]
- Lin Y. S., Green M. R. Mechanism of action of an acidic transcriptional activator in vitro. Cell. 1991 Mar 8;64(5):971–981. doi: 10.1016/0092-8674(91)90321-o. [DOI] [PubMed] [Google Scholar]
- Lu X. B., Heimer J., Rekosh D., Hammarskjöld M. L. U1 small nuclear RNA plays a direct role in the formation of a rev-regulated human immunodeficiency virus env mRNA that remains unspliced. Proc Natl Acad Sci U S A. 1990 Oct;87(19):7598–7602. doi: 10.1073/pnas.87.19.7598. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Luo Y., Yu H., Peterlin B. M. Cellular protein modulates effects of human immunodeficiency virus type 1 Rev. J Virol. 1994 Jun;68(6):3850–3856. doi: 10.1128/jvi.68.6.3850-3856.1994. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Malim M. H., Böhnlein S., Hauber J., Cullen B. R. Functional dissection of the HIV-1 Rev trans-activator--derivation of a trans-dominant repressor of Rev function. Cell. 1989 Jul 14;58(1):205–214. doi: 10.1016/0092-8674(89)90416-9. [DOI] [PubMed] [Google Scholar]
- Malim M. H., Cullen B. R. Rev and the fate of pre-mRNA in the nucleus: implications for the regulation of RNA processing in eukaryotes. Mol Cell Biol. 1993 Oct;13(10):6180–6189. doi: 10.1128/mcb.13.10.6180. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Malim M. H., Hauber J., Fenrick R., Cullen B. R. Immunodeficiency virus rev trans-activator modulates the expression of the viral regulatory genes. Nature. 1988 Sep 8;335(6186):181–183. doi: 10.1038/335181a0. [DOI] [PubMed] [Google Scholar]
- Malim M. H., Hauber J., Le S. Y., Maizel J. V., Cullen B. R. The HIV-1 rev trans-activator acts through a structured target sequence to activate nuclear export of unspliced viral mRNA. Nature. 1989 Mar 16;338(6212):254–257. doi: 10.1038/338254a0. [DOI] [PubMed] [Google Scholar]
- Malim M. H., Tiley L. S., McCarn D. F., Rusche J. R., Hauber J., Cullen B. R. HIV-1 structural gene expression requires binding of the Rev trans-activator to its RNA target sequence. Cell. 1990 Feb 23;60(4):675–683. doi: 10.1016/0092-8674(90)90670-a. [DOI] [PubMed] [Google Scholar]
- McDonald D., Hope T. J., Parslow T. G. Posttranscriptional regulation by the human immunodeficiency virus type 1 Rev and human T-cell leukemia virus type I Rex proteins through a heterologous RNA binding site. J Virol. 1992 Dec;66(12):7232–7238. doi: 10.1128/jvi.66.12.7232-7238.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Meyer B. E., Malim M. H. The HIV-1 Rev trans-activator shuttles between the nucleus and the cytoplasm. Genes Dev. 1994 Jul 1;8(13):1538–1547. doi: 10.1101/gad.8.13.1538. [DOI] [PubMed] [Google Scholar]
- Nosaka T., Takamatsu T., Miyazaki Y., Sano K., Sato A., Kubota S., Sakurai M., Ariumi Y., Nakai M., Fujita S. Cytotoxic activity of rev protein of human immunodeficiency virus type 1 by nucleolar dysfunction. Exp Cell Res. 1993 Nov;209(1):89–102. doi: 10.1006/excr.1993.1289. [DOI] [PubMed] [Google Scholar]
- Olsen H. S., Nelbock P., Cochrane A. W., Rosen C. A. Secondary structure is the major determinant for interaction of HIV rev protein with RNA. Science. 1990 Feb 16;247(4944):845–848. doi: 10.1126/science.2406903. [DOI] [PubMed] [Google Scholar]
- Rosen C. A., Terwilliger E., Dayton A., Sodroski J. G., Haseltine W. A. Intragenic cis-acting art gene-responsive sequences of the human immunodeficiency virus. Proc Natl Acad Sci U S A. 1988 Apr;85(7):2071–2075. doi: 10.1073/pnas.85.7.2071. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ruhl M., Himmelspach M., Bahr G. M., Hammerschmid F., Jaksche H., Wolff B., Aschauer H., Farrington G. K., Probst H., Bevec D. Eukaryotic initiation factor 5A is a cellular target of the human immunodeficiency virus type 1 Rev activation domain mediating trans-activation. J Cell Biol. 1993 Dec;123(6 Pt 1):1309–1320. doi: 10.1083/jcb.123.6.1309. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Spector D. L. Macromolecular domains within the cell nucleus. Annu Rev Cell Biol. 1993;9:265–315. doi: 10.1146/annurev.cb.09.110193.001405. [DOI] [PubMed] [Google Scholar]
- Stutz F., Neville M., Rosbash M. Identification of a novel nuclear pore-associated protein as a functional target of the HIV-1 Rev protein in yeast. Cell. 1995 Aug 11;82(3):495–506. doi: 10.1016/0092-8674(95)90438-7. [DOI] [PubMed] [Google Scholar]
- Taneja K. L., Lifshitz L. M., Fay F. S., Singer R. H. Poly(A) RNA codistribution with microfilaments: evaluation by in situ hybridization and quantitative digital imaging microscopy. J Cell Biol. 1992 Dec;119(5):1245–1260. doi: 10.1083/jcb.119.5.1245. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Vaishnav Y. N., Vaishnav M., Wong-Staal F. Identification and characterization of a nuclear factor that specifically binds to the Rev response element (RRE) of human immunodeficiency virus type 1 (HIV-1). New Biol. 1991 Feb;3(2):142–150. [PubMed] [Google Scholar]
- Wansink D. G., Schul W., van der Kraan I., van Steensel B., van Driel R., de Jong L. Fluorescent labeling of nascent RNA reveals transcription by RNA polymerase II in domains scattered throughout the nucleus. J Cell Biol. 1993 Jul;122(2):283–293. doi: 10.1083/jcb.122.2.283. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zamore P. D., Green M. R. Biochemical characterization of U2 snRNP auxiliary factor: an essential pre-mRNA splicing factor with a novel intranuclear distribution. EMBO J. 1991 Jan;10(1):207–214. doi: 10.1002/j.1460-2075.1991.tb07937.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zapp M. L., Green M. R. Sequence-specific RNA binding by the HIV-1 Rev protein. Nature. 1989 Dec 7;342(6250):714–716. doi: 10.1038/342714a0. [DOI] [PubMed] [Google Scholar]
- Zhang G., Taneja K. L., Singer R. H., Green M. R. Localization of pre-mRNA splicing in mammalian nuclei. Nature. 1994 Dec 22;372(6508):809–812. doi: 10.1038/372809a0. [DOI] [PubMed] [Google Scholar]