Abstract
Splicing of Rous sarcoma virus RNA is regulated in part by a cis-acting intronic RNA element called the negative regulator of splicing (NRS). An NRS mutant affecting nt 916-923 disrupts U11 snRNP binding and reduces NRS activity (Gontarek et al., 1993, Genes & Dev 7:1926-1936). However, we observed that a U15' splice site-like sequence, which overlapped the U11 site, was also disrupted by this mutation. To determine whether the U1 or the U11 site was essential for NRS activity, we analyzed twelve additional mutants involving nt 915-926. All mutations that disrupted the potential base pairing between U1 snRNA and the NRS reduced NRS activity, including single point mutations at nt 915, 916, and 919. The point mutation at nt 919 was partially suppressed by a compensatory base change mutation in U1 snRNA. In contrast, a mutation which strengthened the potential base pairing between the U1 site and the NRS increased NRS activity. Surprisingly, mutations that specifically targeted the U115' splice site consensus sequence increased the levels of unspliced RNA, suggesting U11 binding plays an antagonistic role to NRS activity. We propose that U1 snRNP binding to the NRS inhibits splicing and is regulated by U11 snRNP binding to the overlapping sequence. Competition between U1 and U11 snRNPs would result in the appropriate balance of spliced to unspliced RNAs for optimal viral replication. Further, a virus mutated in the U1/U11 region of the NRS was found to have delayed replication.
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- Arrigo S., Beemon K. Regulation of Rous sarcoma virus RNA splicing and stability. Mol Cell Biol. 1988 Nov;8(11):4858–4867. doi: 10.1128/mcb.8.11.4858. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Arrigo S., Yun M., Beemon K. cis-acting regulatory elements within gag genes of avian retroviruses. Mol Cell Biol. 1987 Jan;7(1):388–397. doi: 10.1128/mcb.7.1.388. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Barker G. F., Beemon K. Nonsense codons within the Rous sarcoma virus gag gene decrease the stability of unspliced viral RNA. Mol Cell Biol. 1991 May;11(5):2760–2768. doi: 10.1128/mcb.11.5.2760. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cook C. R., McNally M. T. SR protein and snRNP requirements for assembly of the Rous sarcoma virus negative regulator of splicing complex in vitro. Virology. 1998 Mar 1;242(1):211–220. doi: 10.1006/viro.1997.8983. [DOI] [PubMed] [Google Scholar]
- Dietrich R. C., Incorvaia R., Padgett R. A. Terminal intron dinucleotide sequences do not distinguish between U2- and U12-dependent introns. Mol Cell. 1997 Dec;1(1):151–160. doi: 10.1016/s1097-2765(00)80016-7. [DOI] [PubMed] [Google Scholar]
- Furth P. A., Choe W. T., Rex J. H., Byrne J. C., Baker C. C. Sequences homologous to 5' splice sites are required for the inhibitory activity of papillomavirus late 3' untranslated regions. Mol Cell Biol. 1994 Aug;14(8):5278–5289. doi: 10.1128/mcb.14.8.5278. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gontarek R. R., McNally M. T., Beemon K. Mutation of an RSV intronic element abolishes both U11/U12 snRNP binding and negative regulation of splicing. Genes Dev. 1993 Oct;7(10):1926–1936. doi: 10.1101/gad.7.10.1926. [DOI] [PubMed] [Google Scholar]
- Gontarek R. R., McNally M. T., Beemon K. Mutation of an RSV intronic element abolishes both U11/U12 snRNP binding and negative regulation of splicing. Genes Dev. 1993 Oct;7(10):1926–1936. doi: 10.1101/gad.7.10.1926. [DOI] [PubMed] [Google Scholar]
- Hall S. L., Padgett R. A. Conserved sequences in a class of rare eukaryotic nuclear introns with non-consensus splice sites. J Mol Biol. 1994 Jun 10;239(3):357–365. doi: 10.1006/jmbi.1994.1377. [DOI] [PubMed] [Google Scholar]
- Hall S. L., Padgett R. A. Requirement of U12 snRNA for in vivo splicing of a minor class of eukaryotic nuclear pre-mRNA introns. Science. 1996 Mar 22;271(5256):1716–1718. doi: 10.1126/science.271.5256.1716. [DOI] [PubMed] [Google Scholar]
- Jiang W., Kanter M. R., Dunkel I., Ramsay R. G., Beemon K. L., Hayward W. S. Minimal truncation of the c-myb gene product in rapid-onset B-cell lymphoma. J Virol. 1997 Sep;71(9):6526–6533. doi: 10.1128/jvi.71.9.6526-6533.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz R. A., Kotler M., Skalka A. M. cis-acting intron mutations that affect the efficiency of avian retroviral RNA splicing: implication for mechanisms of control. J Virol. 1988 Aug;62(8):2686–2695. doi: 10.1128/jvi.62.8.2686-2695.1988. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Katz R. A., Skalka A. M. Control of retroviral RNA splicing through maintenance of suboptimal processing signals. Mol Cell Biol. 1990 Feb;10(2):696–704. doi: 10.1128/mcb.10.2.696. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Kolossova I., Padgett R. A. U11 snRNA interacts in vivo with the 5' splice site of U12-dependent (AU-AC) pre-mRNA introns. RNA. 1997 Mar;3(3):227–233. [PMC free article] [PubMed] [Google Scholar]
- Linial M. Creation of a processed pseudogene by retroviral infection. Cell. 1987 Apr 10;49(1):93–102. doi: 10.1016/0092-8674(87)90759-8. [DOI] [PubMed] [Google Scholar]
- Lou H., Gagel R. F., Berget S. M. An intron enhancer recognized by splicing factors activates polyadenylation. Genes Dev. 1996 Jan 15;10(2):208–219. doi: 10.1101/gad.10.2.208. [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]
- Manley J. L., Tacke R. SR proteins and splicing control. Genes Dev. 1996 Jul 1;10(13):1569–1579. doi: 10.1101/gad.10.13.1569. [DOI] [PubMed] [Google Scholar]
- McNally L. M., McNally M. T. An RNA splicing enhancer-like sequence is a component of a splicing inhibitor element from Rous sarcoma virus. Mol Cell Biol. 1998 Jun;18(6):3103–3111. doi: 10.1128/mcb.18.6.3103. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McNally L. M., McNally M. T. SR protein splicing factors interact with the Rous sarcoma virus negative regulator of splicing element. J Virol. 1996 Feb;70(2):1163–1172. doi: 10.1128/jvi.70.2.1163-1172.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McNally M. T., Beemon K. Intronic sequences and 3' splice sites control Rous sarcoma virus RNA splicing. J Virol. 1992 Jan;66(1):6–11. doi: 10.1128/jvi.66.1.6-11.1992. [DOI] [PMC free article] [PubMed] [Google Scholar]
- McNally M. T., Gontarek R. R., Beemon K. Characterization of Rous sarcoma virus intronic sequences that negatively regulate splicing. Virology. 1991 Nov;185(1):99–108. doi: 10.1016/0042-6822(91)90758-4. [DOI] [PubMed] [Google Scholar]
- Mount S. M. AT-AC introns: an ATtACk on dogma. Science. 1996 Mar 22;271(5256):1690–1692. doi: 10.1126/science.271.5256.1690. [DOI] [PubMed] [Google Scholar]
- O'Reilly M. M., McNally M. T., Beemon K. L. Two strong 5' splice sites and competing, suboptimal 3' splice sites involved in alternative splicing of human immunodeficiency virus type 1 RNA. Virology. 1995 Nov 10;213(2):373–385. doi: 10.1006/viro.1995.0010. [DOI] [PubMed] [Google Scholar]
- Ogert R. A., Lee L. H., Beemon K. L. Avian retroviral RNA element promotes unspliced RNA accumulation in the cytoplasm. J Virol. 1996 Jun;70(6):3834–3843. doi: 10.1128/jvi.70.6.3834-3843.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Oshima M., Odawara T., Matano T., Sakahira H., Kuchino Y., Iwamoto A., Yoshikura H. Possible role of splice acceptor site in expression of unspliced gag-containing message of Moloney murine leukemia virus. J Virol. 1996 Apr;70(4):2286–2295. doi: 10.1128/jvi.70.4.2286-2295.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Purcell D. F., Martin M. A. Alternative splicing of human immunodeficiency virus type 1 mRNA modulates viral protein expression, replication, and infectivity. J Virol. 1993 Nov;67(11):6365–6378. doi: 10.1128/jvi.67.11.6365-6378.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Rein A., Rubin H. Effects of local cell concentrations upon the growth of chick embryo cells in tissue culture. Exp Cell Res. 1968 Mar;49(3):666–678. doi: 10.1016/0014-4827(68)90213-9. [DOI] [PubMed] [Google Scholar]
- SantaLucia J., Jr, Kierzek R., Turner D. H. Stabilities of consecutive A.C, C.C, G.G, U.C, and U.U mismatches in RNA internal loops: Evidence for stable hydrogen-bonded U.U and C.C.+ pairs. Biochemistry. 1991 Aug 20;30(33):8242–8251. doi: 10.1021/bi00247a021. [DOI] [PubMed] [Google Scholar]
- Schwartz D. E., Tizard R., Gilbert W. Nucleotide sequence of Rous sarcoma virus. Cell. 1983 Mar;32(3):853–869. doi: 10.1016/0092-8674(83)90071-5. [DOI] [PubMed] [Google Scholar]
- Sharp P. A., Burge C. B. Classification of introns: U2-type or U12-type. Cell. 1997 Dec 26;91(7):875–879. doi: 10.1016/s0092-8674(00)80479-1. [DOI] [PubMed] [Google Scholar]
- Siebel C. W., Fresco L. D., Rio D. C. The mechanism of somatic inhibition of Drosophila P-element pre-mRNA splicing: multiprotein complexes at an exon pseudo-5' splice site control U1 snRNP binding. Genes Dev. 1992 Aug;6(8):1386–1401. doi: 10.1101/gad.6.8.1386. [DOI] [PubMed] [Google Scholar]
- Smith M. R., Smith R. E., Dunkel I., Hou V., Beemon K. L., Hayward W. S. Genetic determinant of rapid-onset B-cell lymphoma by avian leukosis virus. J Virol. 1997 Sep;71(9):6534–6540. doi: 10.1128/jvi.71.9.6534-6540.1997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoltzfus C. M., Fogarty S. J. Multiple regions in the Rous sarcoma virus src gene intron act in cis to affect the accumulation of unspliced RNA. J Virol. 1989 Apr;63(4):1669–1676. doi: 10.1128/jvi.63.4.1669-1676.1989. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoltzfus C. M. Synthesis and processing of avian sarcoma retrovirus RNA. Adv Virus Res. 1988;35:1–38. doi: 10.1016/s0065-3527(08)60707-1. [DOI] [PubMed] [Google Scholar]
- Tarn W. Y., Steitz J. A. A novel spliceosome containing U11, U12, and U5 snRNPs excises a minor class (AT-AC) intron in vitro. Cell. 1996 Mar 8;84(5):801–811. doi: 10.1016/s0092-8674(00)81057-0. [DOI] [PubMed] [Google Scholar]
- Tarn W. Y., Steitz J. A. Highly diverged U4 and U6 small nuclear RNAs required for splicing rare AT-AC introns. Science. 1996 Sep 27;273(5283):1824–1832. doi: 10.1126/science.273.5283.1824. [DOI] [PubMed] [Google Scholar]
- Tarn W. Y., Steitz J. A. Pre-mRNA splicing: the discovery of a new spliceosome doubles the challenge. Trends Biochem Sci. 1997 Apr;22(4):132–137. doi: 10.1016/s0968-0004(97)01018-9. [DOI] [PubMed] [Google Scholar]
- Wang J., Xiao S. H., Manley J. L. Genetic analysis of the SR protein ASF/SF2: interchangeability of RS domains and negative control of splicing. Genes Dev. 1998 Jul 15;12(14):2222–2233. doi: 10.1101/gad.12.14.2222. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wassarman K. M., Steitz J. A. The low-abundance U11 and U12 small nuclear ribonucleoproteins (snRNPs) interact to form a two-snRNP complex. Mol Cell Biol. 1992 Mar;12(3):1276–1285. doi: 10.1128/mcb.12.3.1276. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weldon R. A., Jr, Wills J. W. Characterization of a small (25-kilodalton) derivative of the Rous sarcoma virus Gag protein competent for particle release. J Virol. 1993 Sep;67(9):5550–5561. doi: 10.1128/jvi.67.9.5550-5561.1993. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Wu H. J., Gaubier-Comella P., Delseny M., Grellet F., Van Montagu M., Rouzé R. Non-canonical introns are at least 10(9) years old. Nat Genet. 1996 Dec;14(4):383–384. doi: 10.1038/ng1296-383. [DOI] [PubMed] [Google Scholar]
- Wu Q., Krainer A. R. U1-mediated exon definition interactions between AT-AC and GT-AG introns. Science. 1996 Nov 8;274(5289):1005–1008. doi: 10.1126/science.274.5289.1005. [DOI] [PubMed] [Google Scholar]
- Yu Y. T., Steitz J. A. Site-specific crosslinking of mammalian U11 and u6atac to the 5' splice site of an AT-AC intron. Proc Natl Acad Sci U S A. 1997 Jun 10;94(12):6030–6035. doi: 10.1073/pnas.94.12.6030. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang L., Stoltzfus C. M. A suboptimal src 3' splice site is necessary for efficient replication of Rous sarcoma virus. Virology. 1995 Feb 1;206(2):1099–1107. doi: 10.1006/viro.1995.1033. [DOI] [PubMed] [Google Scholar]
- Zhuang Y., Weiner A. M. A compensatory base change in U1 snRNA suppresses a 5' splice site mutation. Cell. 1986 Sep 12;46(6):827–835. doi: 10.1016/0092-8674(86)90064-4. [DOI] [PubMed] [Google Scholar]