Abstract
Generally, mRNAs that prematurely terminate translation are abnormally low in abundance. In the case of mammalian cells, nonsense codons most often mediate a reduction in the abundance of newly synthesized, nucleus-associated mRNA by a mechanism that is not well understood. With the aim of defining cis-acting sequences that are important to the reduction process, the effects of particular beta-globin gene rearrangements on the metabolism of beta-globin mRNAs harboring one of a series of nonsense codons have been assessed. Results indicate that nonsense codons located 54 bp or more upstream of the 3'-most intron, intron 2, reduce the abundance of nucleus-associated mRNA to 10-15% of normal without altering the level of either of the two introns within pre-mRNA. The level of cytoplasmic mRNA is also reduced to 10-15% of normal, indicating that decay does not take place once the mRNA is released from an association with nuclei into the cytoplasm. A nonsense codon within exon 2 that does not reduce mRNA abundance can be converted to the type that does by (1) inserting a sufficiently large in-frame sequence immediately upstream of intron 2 or (2) deleting and reinserting intron 2 a sufficient distance downstream of its usual position. These findings indicate that only those nonsense codons located more than 54 bp upstream of the 3'-most intron reduce beta-globin mRNA abundance, which is remarkably consistent with which nonsense codons within the triosephosphate isomerase (TPI) gene reduce TPI mRNA abundance. We propose that the 3'-most exon-exon junction of beta-globin mRNA and, possibly, most mRNAs is marked by the removal of the 3'-most intron during pre-mRNA splicing and that the "mark" accompanies mRNA during transport to the cytoplasm. When cytoplasmic ribosomes terminate translation more than 54 nt upstream of the mark during or immediately after transport, the mRNA is subjected to nonsense-mediated decay. The finding that deletion of beta-globin intron 2 does not appreciably alter the effect of any nonsense codon on beta-globin mRNA abundance suggests that another cis-acting sequence functions in nonsense-mediated decay comparably to intron 2, at least in the absence of intron 2, possibly as a fail-safe mechanism. The analysis of deletions and insertions indicates that this sequence resides within the coding region and can be functionally substituted by intron 2.
Full Text
The Full Text of this article is available as a PDF (908.8 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- Aoufouchi S., Yélamos J., Milstein C. Nonsense mutations inhibit RNA splicing in a cell-free system: recognition of mutant codon is independent of protein synthesis. Cell. 1996 May 3;85(3):415–422. doi: 10.1016/s0092-8674(00)81119-8. [DOI] [PubMed] [Google Scholar]
- Applequist S. E., Selg M., Raman C., Jäck H. M. Cloning and characterization of HUPF1, a human homolog of the Saccharomyces cerevisiae nonsense mRNA-reducing UPF1 protein. Nucleic Acids Res. 1997 Feb 15;25(4):814–821. doi: 10.1093/nar/25.4.814. [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]
- Barker G. F., Beemon K. Rous sarcoma virus RNA stability requires an open reading frame in the gag gene and sequences downstream of the gag-pol junction. Mol Cell Biol. 1994 Mar;14(3):1986–1996. doi: 10.1128/mcb.14.3.1986. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belgrader P., Cheng J., Maquat L. E. Evidence to implicate translation by ribosomes in the mechanism by which nonsense codons reduce the nuclear level of human triosephosphate isomerase mRNA. Proc Natl Acad Sci U S A. 1993 Jan 15;90(2):482–486. doi: 10.1073/pnas.90.2.482. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belgrader P., Cheng J., Zhou X., Stephenson L. S., Maquat L. E. Mammalian nonsense codons can be cis effectors of nuclear mRNA half-life. Mol Cell Biol. 1994 Dec;14(12):8219–8228. doi: 10.1128/mcb.14.12.8219. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Belgrader P., Maquat L. E. Nonsense but not missense mutations can decrease the abundance of nuclear mRNA for the mouse major urinary protein, while both types of mutations can facilitate exon skipping. Mol Cell Biol. 1994 Sep;14(9):6326–6336. doi: 10.1128/mcb.14.9.6326. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caponigro G., Parker R. Mechanisms and control of mRNA turnover in Saccharomyces cerevisiae. Microbiol Rev. 1996 Mar;60(1):233–249. doi: 10.1128/mr.60.1.233-249.1996. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carter M. S., Li S., Wilkinson M. F. A splicing-dependent regulatory mechanism that detects translation signals. EMBO J. 1996 Nov 1;15(21):5965–5975. [PMC free article] [PubMed] [Google Scholar]
- Chang M. L., Artymiuk P. J., Wu X., Hollán S., Lammi A., Maquat L. E. Human triosephosphate isomerase deficiency resulting from mutation of Phe-240. Am J Hum Genet. 1993 Jun;52(6):1260–1269. [PMC free article] [PubMed] [Google Scholar]
- Cheng J., Belgrader P., Zhou X., Maquat L. E. Introns are cis effectors of the nonsense-codon-mediated reduction in nuclear mRNA abundance. Mol Cell Biol. 1994 Sep;14(9):6317–6325. doi: 10.1128/mcb.14.9.6317. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cheng J., Fogel-Petrovic M., Maquat L. E. Translation to near the distal end of the penultimate exon is required for normal levels of spliced triosephosphate isomerase mRNA. Mol Cell Biol. 1990 Oct;10(10):5215–5225. doi: 10.1128/mcb.10.10.5215. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Cheng J., Maquat L. E. Nonsense codons can reduce the abundance of nuclear mRNA without affecting the abundance of pre-mRNA or the half-life of cytoplasmic mRNA. Mol Cell Biol. 1993 Mar;13(3):1892–1902. doi: 10.1128/mcb.13.3.1892. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Dietz H. C., Kendzior R. J., Jr Maintenance of an open reading frame as an additional level of scrutiny during splice site selection. Nat Genet. 1994 Oct;8(2):183–188. doi: 10.1038/ng1094-183. [DOI] [PubMed] [Google Scholar]
- Dietz H. C., Valle D., Francomano C. A., Kendzior R. J., Jr, Pyeritz R. E., Cutting G. R. The skipping of constitutive exons in vivo induced by nonsense mutations. Science. 1993 Jan 29;259(5095):680–683. doi: 10.1126/science.8430317. [DOI] [PubMed] [Google Scholar]
- Hagan K. W., Ruiz-Echevarria M. J., Quan Y., Peltz S. W. Characterization of cis-acting sequences and decay intermediates involved in nonsense-mediated mRNA turnover. Mol Cell Biol. 1995 Feb;15(2):809–823. doi: 10.1128/mcb.15.2.809. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hall G. W., Thein S. Nonsense codon mutations in the terminal exon of the beta-globin gene are not associated with a reduction in beta-mRNA accumulation: a mechanism for the phenotype of dominant beta-thalassemia. Blood. 1994 Apr 15;83(8):2031–2037. [PubMed] [Google Scholar]
- Hawkins J. D. A survey on intron and exon lengths. Nucleic Acids Res. 1988 Nov 11;16(21):9893–9908. doi: 10.1093/nar/16.21.9893. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Jacobson A., Peltz S. W. Interrelationships of the pathways of mRNA decay and translation in eukaryotic cells. Annu Rev Biochem. 1996;65:693–739. doi: 10.1146/annurev.bi.65.070196.003401. [DOI] [PubMed] [Google Scholar]
- Kugler W., Enssle J., Hentze M. W., Kulozik A. E. Nuclear degradation of nonsense mutated beta-globin mRNA: a post-transcriptional mechanism to protect heterozygotes from severe clinical manifestations of beta-thalassemia? Nucleic Acids Res. 1995 Feb 11;23(3):413–418. doi: 10.1093/nar/23.3.413. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Li S., Leonard D., Wilkinson M. F. T cell receptor (TCR) mini-gene mRNA expression regulated by nonsense codons: a nuclear-associated translation-like mechanism. J Exp Med. 1997 Mar 17;185(6):985–992. doi: 10.1084/jem.185.6.985. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lim S. K., Maquat L. E. Human beta-globin mRNAs that harbor a nonsense codon are degraded in murine erythroid tissues to intermediates lacking regions of exon I or exons I and II that have a cap-like structure at the 5' termini. EMBO J. 1992 Sep;11(9):3271–3278. doi: 10.1002/j.1460-2075.1992.tb05405.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lim S. K., Sigmund C. D., Gross K. W., Maquat L. E. Nonsense codons in human beta-globin mRNA result in the production of mRNA degradation products. Mol Cell Biol. 1992 Mar;12(3):1149–1161. doi: 10.1128/mcb.12.3.1149. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lim S., Mullins J. J., Chen C. M., Gross K. W., Maquat L. E. Novel metabolism of several beta zero-thalassemic beta-globin mRNAs in the erythroid tissues of transgenic mice. EMBO J. 1989 Sep;8(9):2613–2619. doi: 10.1002/j.1460-2075.1989.tb08401.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lozano F., Maertzdorf B., Pannell R., Milstein C. Low cytoplasmic mRNA levels of immunoglobulin kappa light chain genes containing nonsense codons correlate with inefficient splicing. EMBO J. 1994 Oct 3;13(19):4617–4622. doi: 10.1002/j.1460-2075.1994.tb06783.x. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Maquat L. E. Defects in RNA splicing and the consequence of shortened translational reading frames. Am J Hum Genet. 1996 Aug;59(2):279–286. [PMC free article] [PubMed] [Google Scholar]
- Maquat L. E. When cells stop making sense: effects of nonsense codons on RNA metabolism in vertebrate cells. RNA. 1995 Jul;1(5):453–465. [PMC free article] [PubMed] [Google Scholar]
- Mehlin H., Daneholt B., Skoglund U. Translocation of a specific premessenger ribonucleoprotein particle through the nuclear pore studied with electron microscope tomography. Cell. 1992 May 15;69(4):605–613. doi: 10.1016/0092-8674(92)90224-z. [DOI] [PubMed] [Google Scholar]
- Moriarty P. M., Reddy C. C., Maquat L. E. Selenium deficiency reduces the abundance of mRNA for Se-dependent glutathione peroxidase 1 by a UGA-dependent mechanism likely to be nonsense codon-mediated decay of cytoplasmic mRNA. Mol Cell Biol. 1998 May;18(5):2932–2939. doi: 10.1128/mcb.18.5.2932. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Muhlrad D., Parker R. Premature translational termination triggers mRNA decapping. Nature. 1994 Aug 18;370(6490):578–581. doi: 10.1038/370578a0. [DOI] [PubMed] [Google Scholar]
- Naeger L. K., Schoborg R. V., Zhao Q., Tullis G. E., Pintel D. J. Nonsense mutations inhibit splicing of MVM RNA in cis when they interrupt the reading frame of either exon of the final spliced product. Genes Dev. 1992 Jun;6(6):1107–1119. doi: 10.1101/gad.6.6.1107. [DOI] [PubMed] [Google Scholar]
- Nagy E., Maquat L. E. A rule for termination-codon position within intron-containing genes: when nonsense affects RNA abundance. Trends Biochem Sci. 1998 Jun;23(6):198–199. doi: 10.1016/s0968-0004(98)01208-0. [DOI] [PubMed] [Google Scholar]
- Peltz S. W., Brown A. H., Jacobson A. mRNA destabilization triggered by premature translational termination depends on at least three cis-acting sequence elements and one trans-acting factor. Genes Dev. 1993 Sep;7(9):1737–1754. doi: 10.1101/gad.7.9.1737. [DOI] [PubMed] [Google Scholar]
- Peltz S. W., He F., Welch E., Jacobson A. Nonsense-mediated mRNA decay in yeast. Prog Nucleic Acid Res Mol Biol. 1994;47:271–298. doi: 10.1016/s0079-6603(08)60254-8. [DOI] [PubMed] [Google Scholar]
- Perlick H. A., Medghalchi S. M., Spencer F. A., Kendzior R. J., Jr, Dietz H. C. Mammalian orthologues of a yeast regulator of nonsense transcript stability. Proc Natl Acad Sci U S A. 1996 Oct 1;93(20):10928–10932. doi: 10.1073/pnas.93.20.10928. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Ruiz-Echevarria M. J., Czaplinski K., Peltz S. W. Making sense of nonsense in yeast. Trends Biochem Sci. 1996 Nov;21(11):433–438. doi: 10.1016/s0968-0004(96)10055-4. [DOI] [PubMed] [Google Scholar]
- Ruiz-Echevarria M. J., Peltz S. W. Utilizing the GCN4 leader region to investigate the role of the sequence determinants in nonsense-mediated mRNA decay. EMBO J. 1996 Jun 3;15(11):2810–2819. [PMC free article] [PubMed] [Google Scholar]
- Ruiz-Echevarría M. J., González C. I., Peltz S. W. Identifying the right stop: determining how the surveillance complex recognizes and degrades an aberrant mRNA. EMBO J. 1998 Jan 15;17(2):575–589. doi: 10.1093/emboj/17.2.575. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Shyu A. B., Greenberg M. E., Belasco J. G. The c-fos transcript is targeted for rapid decay by two distinct mRNA degradation pathways. Genes Dev. 1989 Jan;3(1):60–72. doi: 10.1101/gad.3.1.60. [DOI] [PubMed] [Google Scholar]
- Visa N., Alzhanova-Ericsson A. T., Sun X., Kiseleva E., Björkroth B., Wurtz T., Daneholt B. A pre-mRNA-binding protein accompanies the RNA from the gene through the nuclear pores and into polysomes. Cell. 1996 Jan 26;84(2):253–264. doi: 10.1016/s0092-8674(00)80980-0. [DOI] [PubMed] [Google Scholar]
- Weng Y., Czaplinski K., Peltz S. W. Genetic and biochemical characterization of mutations in the ATPase and helicase regions of the Upf1 protein. Mol Cell Biol. 1996 Oct;16(10):5477–5490. doi: 10.1128/mcb.16.10.5477. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Weng Y., Czaplinski K., Peltz S. W. Identification and characterization of mutations in the UPF1 gene that affect nonsense suppression and the formation of the Upf protein complex but not mRNA turnover. Mol Cell Biol. 1996 Oct;16(10):5491–5506. doi: 10.1128/mcb.16.10.5491. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang J., Maquat L. E. Evidence that the decay of nucleus-associated nonsense mRNA for human triosephosphate isomerase involves nonsense codon recognition after splicing. RNA. 1996 Mar;2(3):235–243. [PMC free article] [PubMed] [Google Scholar]
- Zhang J., Maquat L. E. Evidence that translation reinitiation abrogates nonsense-mediated mRNA decay in mammalian cells. EMBO J. 1997 Feb 17;16(4):826–833. doi: 10.1093/emboj/16.4.826. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zhang S., Ruiz-Echevarria M. J., Quan Y., Peltz S. W. Identification and characterization of a sequence motif involved in nonsense-mediated mRNA decay. Mol Cell Biol. 1995 Apr;15(4):2231–2244. doi: 10.1128/mcb.15.4.2231. [DOI] [PMC free article] [PubMed] [Google Scholar]