Initiation of Translation of the FMR1 MRNA Occurs Predominantly Through 5'-end-dependent Ribosomal Scanning

Overview

Journal J Mol Biol

Publisher Elsevier

Specialties Microbiology
Molecular Biology

Date 2011 Jan 18

PMID 21237174

Citations 20

Authors

Anna L Ludwig

John W B Hershey

Paul J Hagerman

Affiliations

Soon will be listed here.

Abstract

The fragile X mental retardation 1 (FMR1) gene contains a CGG repeat within its 5' untranslated region (5'UTR) that, when expanded to 55-200 CGG repeats (premutation allele), can result in the late-onset neurodegenerative disorder, fragile X-associated tremor/ataxia syndrome. The CGG repeat is expected to form a highly stable secondary structure that is capable of inhibiting 5'-cap-dependent translation. Paradoxically, translation in vivo is only mildly impaired within the premutation range, suggesting that other modes of translation initiation may be operating. To address this issue, we translated in vitro a set of reporter mRNAs containing between 0 and 99 CGG repeats in either native (FMR1) or unrelated (heterologous) 5'UTR context. The 5'-cap dependence of translation was assessed by inserting a stable hairpin (HP) near the 5' end of the mRNAs. The results of the current studies indicate that translation initiation of the FMR1 mRNA occurs primarily by scanning, with little evidence of internal ribosome entry or shunting. Additionally, the efficiency of translation initiation depends on transcription start site selection, with the shorter 5'UTR (downstream transcription start site I) translating with greater efficiency compared to the longer mRNA (start site III) for all CGG-repeat elements studied. Lastly, an HP previously shown to block translation gave differing results depending on the 5'UTR context, in one case initiating translation from within the HP.

Citing Articles

Size matters: Fighting repeat expansion size in fragile X syndrome using antisense oligonucleotides.

Shankar V, Klann E Proc Natl Acad Sci U S A. 2023; 120(30):e2309678120.

PMID: 37440569 PMC: 10372623. DOI: 10.1073/pnas.2309678120.

A native function for RAN translation and CGG repeats in regulating fragile X protein synthesis.

Rodriguez C, Wright S, Kearse M, Haenfler J, Flores B, Liu Y Nat Neurosci. 2020; 23(3):386-397.

PMID: 32066985 PMC: 7668390. DOI: 10.1038/s41593-020-0590-1.

hnRNP Q Regulates Internal Ribosome Entry Site-Mediated Translation in Neurons.

Choi J, Kim S, Jeong Y, Kim S, Min K, Kim K Mol Cell Biol. 2018; 39(4).

PMID: 30478144 PMC: 6362317. DOI: 10.1128/MCB.00371-18.

Curvilinear Association Between Language Disfluency and CGG Repeat Size Across the Normal, Intermediate, and Premutation Range.

Klusek J, Porter A, Abbeduto L, Adayev T, Tassone F, Mailick M Front Genet. 2018; 9:344.

PMID: 30197656 PMC: 6118037. DOI: 10.3389/fgene.2018.00344.

Vagal Tone as a Putative Mechanism for Pragmatic Competence: An Investigation of Carriers of the FMR1 Premutation.

Klusek J, Fairchild A, Roberts J J Autism Dev Disord. 2018; 49(1):197-208.

PMID: 30097759 PMC: 6855249. DOI: 10.1007/s10803-018-3714-7.

References

Berry-Kravis E, Abrams L, Coffey S, Hall D, Greco C, Gane L . Fragile X-associated tremor/ataxia syndrome: clinical features, genetics, and testing guidelines. Mov Disord. 2007; 22(14):2018-30, quiz 2140. DOI: 10.1002/mds.21493. View

Bassell G, Warren S . Fragile X syndrome: loss of local mRNA regulation alters synaptic development and function. Neuron. 2008; 60(2):201-14. PMC: 3691995. DOI: 10.1016/j.neuron.2008.10.004. View

Sherrill K, Lloyd R . Translation of cIAP2 mRNA is mediated exclusively by a stress-modulated ribosome shunt. Mol Cell Biol. 2008; 28(6):2011-22. PMC: 2268400. DOI: 10.1128/MCB.01446-07. View

Verkerk A, Pieretti M, Sutcliffe J, Fu Y, Kuhl D, Pizzuti A . Identification of a gene (FMR-1) containing a CGG repeat coincident with a breakpoint cluster region exhibiting length variation in fragile X syndrome. Cell. 1991; 65(5):905-14. DOI: 10.1016/0092-8674(91)90397-h. View

Chen L, Tassone F, Sahota P, Hagerman P . The (CGG)n repeat element within the 5' untranslated region of the FMR1 message provides both positive and negative cis effects on in vivo translation of a downstream reporter. Hum Mol Genet. 2003; 12(23):3067-74. DOI: 10.1093/hmg/ddg331. View

Filbin M, Kieft J . Toward a structural understanding of IRES RNA function. Curr Opin Struct Biol. 2009; 19(3):267-76. PMC: 2757110. DOI: 10.1016/j.sbi.2009.03.005. View

Hagerman P, Hagerman R . The fragile-X premutation: a maturing perspective. Am J Hum Genet. 2004; 74(5):805-16. PMC: 1181976. DOI: 10.1086/386296. View

Brouwer J, Willemsen R, Oostra B . Microsatellite repeat instability and neurological disease. Bioessays. 2009; 31(1):71-83. PMC: 4321794. DOI: 10.1002/bies.080122. View

Sobczak K, de Mezer M, Michlewski G, Krol J, Krzyzosiak W . RNA structure of trinucleotide repeats associated with human neurological diseases. Nucleic Acids Res. 2003; 31(19):5469-82. PMC: 206466. DOI: 10.1093/nar/gkg766. View

10.

Wang Y, Gellibolian R, Shimizu M, Wells R, Griffith J . Long CCG triplet repeat blocks exclude nucleosomes: a possible mechanism for the nature of fragile sites in chromosomes. J Mol Biol. 1996; 263(4):511-6. DOI: 10.1006/jmbi.1996.0593. View

11.

Pisareva V, Pisarev A, Komar A, Hellen C, Pestova T . Translation initiation on mammalian mRNAs with structured 5'UTRs requires DExH-box protein DHX29. Cell. 2008; 135(7):1237-50. PMC: 2948571. DOI: 10.1016/j.cell.2008.10.037. View

12.

Tassone F, Hagerman R, Taylor A, Gane L, Godfrey T, Hagerman P . Elevated levels of FMR1 mRNA in carrier males: a new mechanism of involvement in the fragile-X syndrome. Am J Hum Genet. 2000; 66(1):6-15. PMC: 1288349. DOI: 10.1086/302720. View

13.

Laemmli U . Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature. 1970; 227(5259):680-5. DOI: 10.1038/227680a0. View

14.

Ryabova L, Pooggin M, Hohn T . Translation reinitiation and leaky scanning in plant viruses. Virus Res. 2005; 119(1):52-62. DOI: 10.1016/j.virusres.2005.10.017. View

15.

Amiri K, Hagerman R, Hagerman P . Fragile X-associated tremor/ataxia syndrome: an aging face of the fragile X gene. Arch Neurol. 2008; 65(1):19-25. DOI: 10.1001/archneurol.2007.30. View

16.

Bailey Jr D, Raspa M, Olmsted M, Holiday D . Co-occurring conditions associated with FMR1 gene variations: findings from a national parent survey. Am J Med Genet A. 2008; 146A(16):2060-9. DOI: 10.1002/ajmg.a.32439. View

17.

Mauro V, Chappell S, Dresios J . Analysis of ribosomal shunting during translation initiation in eukaryotic mRNAs. Methods Enzymol. 2007; 429:323-54. DOI: 10.1016/S0076-6879(07)29015-9. View

18.

Tassone F, Hagerman R, Loesch D, Lachiewicz A, Taylor A, Hagerman P . Fragile X males with unmethylated, full mutation trinucleotide repeat expansions have elevated levels of FMR1 messenger RNA. Am J Med Genet. 2000; 94(3):232-6. DOI: 10.1002/1096-8628(20000918)94:3<232::aid-ajmg9>3.0.co;2-h. View

19.

Hessl D, Tassone F, Loesch D, Berry-Kravis E, Leehey M, Gane L . Abnormal elevation of FMR1 mRNA is associated with psychological symptoms in individuals with the fragile X premutation. Am J Med Genet B Neuropsychiatr Genet. 2005; 139B(1):115-21. DOI: 10.1002/ajmg.b.30241. View

20.

Pfeiffer B, Huber K . The state of synapses in fragile X syndrome. Neuroscientist. 2009; 15(5):549-67. PMC: 2762019. DOI: 10.1177/1073858409333075. View