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A circRNA from SEPALLATA3 regulates splicing of its cognate mRNA through R-loop formation

Abstract

Circular RNAs (circRNAs) are a diverse and abundant class of hyper-stable, non-canonical RNAs that arise through a form of alternative splicing (AS) called back-splicing. These single-stranded, covalently-closed circRNA molecules have been identified in all eukaryotic kingdoms of life1, yet their functions have remained elusive. Here, we report that circRNAs can be used as bona fide biomarkers of functional, exon-skipped AS variants in Arabidopsis, including in the homeotic MADS-box transcription factor family. Furthermore, we demonstrate that circRNAs derived from exon 6 of the SEPALLATA3 (SEP3) gene increase abundance of the cognate exon-skipped AS variant (SEP3.3 which lacks exon 6), in turn driving floral homeotic phenotypes. Toward demonstrating the underlying mechanism, we show that the SEP3 exon 6 circRNA can bind strongly to its cognate DNA locus, forming an RNA:DNA hybrid, or R-loop, whereas the linear RNA equivalent bound significantly more weakly to DNA. R-loop formation results in transcriptional pausing, which has been shown to coincide with splicing factor recruitment and AS24. This report presents a novel mechanistic insight for how at least a subset of circRNAs probably contribute to increased splicing efficiency of their cognate exon-skipped messenger RNA and provides the first evidence of an organismal-level phenotype mediated by circRNA manipulation.

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Figure 1: CircRNAs are bona fide biomarkers of AS in Arabidopsis MADS TFs.
Figure 2: Circular RNA skews AS of its cognate mRNA driving homeotic phenotypes.
Figure 3: CircRNAs can form stable R-loops (RNA:DNA hybrids), which are stronger than with linear RNA.

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References

  1. Wang, P. L. et al. Circular RNA is expressed across the eukaryotic tree of life. PLoS ONE 9, e90859 (2014).

    Article  Google Scholar 

  2. Wongsurawat, T., Jenjaroenpun, P., Kwoh, C. K. & Kuznetsov, V. Quantitative model of R-loop forming structures reveals a novel level of RNA–DNA interactome complexity. Nucleic Acids Res. 40, e16 (2012).

    Article  CAS  Google Scholar 

  3. El Hage, A., Webb, S., Kerr, A. & Tollervey, D. Genome-wide distribution of RNA-DNA hybrids identifies RNase H targets in tRNA genes, retrotransposons and mitochondria. PLoS Genet. 10, e1004716 (2014).

    Article  Google Scholar 

  4. Alexander, R. D., Innocente, S. A., Barrass, J. D. & Beggs, J. D. Splicing-dependent RNA polymerase pausing in yeast. Mol. Cell 40, 582–593 (2010).

    Article  CAS  Google Scholar 

  5. Nilsen, T. W. & Graveley, B. R. Expansion of the eukaryotic proteome by alternative splicing. Nature 463, 457–463 (2010).

    Article  CAS  Google Scholar 

  6. Staiger, D. Shaping the Arabidopsis transcriptome through alternative splicing. Adv. Bot. 2015, 419428 (2015).

    Google Scholar 

  7. Ye, C.-Y., Chen, L., Liu, C., Zhu, Q.-H. & Fan, L. Widespread noncoding circular RNAs in plants. New Phytol. 208, 88–95 (2015).

    Article  CAS  Google Scholar 

  8. Ashwal-Fluss, R. et al. circRNA biogenesis competes with pre-mRNA splicing. Mol. Cell 56, 55–66 (2014).

    Article  CAS  Google Scholar 

  9. Kelly, S., Greenman, C., Cook, P. R. & Papantonis, A. Exon skipping is correlated with exon circularization. J. Mol. Biol. 427, 2414–2417 (2015).

    Article  CAS  Google Scholar 

  10. Chen, L.-L. The biogenesis and emerging roles of circular RNAs. Nat. Rev. Mol. Cell Biol. 17, 205–211 (2016).

    Article  CAS  Google Scholar 

  11. Sun, X. et al. Integrative analysis of Arabidopsis thaliana transcriptomics reveals intuitive splicing mechanism for circular RNA. FEBS Lett. 590, 3510–3516 (2016).

    Article  CAS  Google Scholar 

  12. Sturgill, D. et al. Design of RNA splicing analysis null models for post hoc filtering of Drosophila head RNA-Seq data with the splicing analysis kit (Spanki). BMC Bioinform. 14, 320 (2013).

    Article  Google Scholar 

  13. Theissen, G. & Saedler, H. Plant biology. Floral quartets . Nature 409, 469–471 (2001).

    Article  CAS  Google Scholar 

  14. Severing, E. I. et al. Predicting the impact of alternative splicing on plant MADS domain protein function. PLoS ONE 7, e30524 (2012).

    Article  CAS  Google Scholar 

  15. Posé, D. et al. Temperature-dependent regulation of flowering by antagonistic FLM variants. Nature 503, 414–417 (2013).

    Article  Google Scholar 

  16. Lee, J. H. et al. Regulation of temperature-responsive flowering by MADS-box transcription factor repressors. Science 342, 628–632 (2013).

    Article  CAS  Google Scholar 

  17. Sureshkumar, S., Dent, C., Seleznev, A., Tasset, C. & Balasubramanian, S. Nonsense-mediated mRNA decay modulates FLM-dependent thermosensory flowering response in Arabidopsis. Nat. Plants 2, 16055 (2016).

    Article  CAS  Google Scholar 

  18. Puranik, S. et al. Structural basis for the oligomerization of the MADS domain transcription factor SEPALLATA3 in Arabidopsis. Plant Cell 26, 3603–3615 (2014).

    Article  CAS  Google Scholar 

  19. Kaufmann, K. et al. Target genes of the MADS transcription factor SEPALLATA3: integration of developmental and hormonal pathways in the Arabidopsis flower. PLoS Biol. 7, e1000090 (2009).

    Article  Google Scholar 

  20. Silva, C. S. et al. Evolution of the plant reproduction master regulators LFY and the MADS transcription factors: the role of protein structure in the evolutionary development of the flower. Front. Plant Sci. 6, 1193 (2015).

    PubMed  Google Scholar 

  21. Jeck, W. R. & Sharpless, N. E. Detecting and characterizing circular RNAs. Nat. Biotechnol. 32, 453–461 (2014).

    Article  CAS  Google Scholar 

  22. Gruber, A. R., Lorenz, R., Bernhart, S. H., Neuböck, R. & Hofacker, I. L. The Vienna RNA websuite. Nucleic Acids Res. 36, W70–W74 (2008).

    Article  CAS  Google Scholar 

  23. Dujardin, G. et al. How slow RNA polymerase II elongation favors alternative exon skipping. Mol. Cell 54, 683–690 (2014).

    Article  CAS  Google Scholar 

  24. Conn, S. J. et al. The RNA binding protein quaking regulates formation of circRNAs. Cell 160, 1125–1134 (2015).

    Article  CAS  Google Scholar 

  25. Memczak, S. et al. Circular RNAs are a large class of animal RNAs with regulatory potency. Nature 495, 333–338 (2013).

    Article  CAS  Google Scholar 

  26. Hansen, T. B. et al. Natural RNA circles function as efficient microRNA sponges. Nature 495, 384–388 (2013).

    Article  CAS  Google Scholar 

  27. Zhang, Y. et al. Circular intronic long noncoding RNAs. Mol. Cell 51, 792–806 (2013).

    Article  CAS  Google Scholar 

  28. Bensmihen, S. et al. Analysis of an activated ABI5 allele using a new selection method for transgenic Arabidopsis seeds. FEBS Lett. 561, 127–131 (2004).

    Article  CAS  Google Scholar 

  29. Box, M. S., Coustham, V., Dean, C. & Mylne, J. S. Protocol: a simple phenol-based method for 96-well extraction of high quality RNA from Arabidopsis. Plant Methods 7, 7 (2011).

    Article  CAS  Google Scholar 

  30. Conn, S. J. et al. Cell-specific vacuolar calcium storage mediated by CAX1 regulates apoplastic calcium concentration, gas exchange, and plant productivity in Arabidopsis. Plant Cell 23, 240–257 (2011).

    Article  CAS  Google Scholar 

  31. Chen, P. B., Chen, H. V., Acharya, D., Rando, O. J. & Fazzio, T. G. R loops regulate promoter-proximal chromatin architecture and cellular differentiation. Nat. Struct. Mol. Biol. 22, 999–1007 (2015).

    Article  CAS  Google Scholar 

  32. Wahba, L., Gore, S. K. & Koshland, D. The homologous recombination machinery modulates the formation of RNA-DNA hybrids and associated chromosome instability. eLife 2, e00505 (2013).

    Article  Google Scholar 

  33. Kershaw, C. J. & O'Keefe, R. T. Splint ligation of RNA with T4 DNA ligase. Methods Mol. Biol. Clifton NJ 941, 257–269 (2012).

    Article  CAS  Google Scholar 

  34. Chen, C. Y. & Sarnow, P. Initiation of protein synthesis by the eukaryotic translational apparatus on circular RNAs. Science 268, 415–417 (1995).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

Research reported in this publication was supported by the Agence Nationale de la Recherche (Projet FLOPINET), Centre National de la Recherche Scientifique funding to S.J.C., NHMRC project grant funding (GNT1089167) to S.J.C., Australian Research Council Future Fellowship (FT160100318) to S.J.C., ATIP-Avenir and LabEx GRAL (ANR-10-LABX-49-01) program funding to C.Z., Premier's Research and Industry Fund grant provided by the South Australian Government Department of State Development to V.T. and CEA Irtelis fellowship to A.N. Mouse monoclonal S9.6 antibody was kindly donated by S. Leppla (National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, Maryland, USA).

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S.J.C. and C.Z. conceived the project. V.M.C., S.J.C., V.H., A.N., S.A.C., Gi.C., Go.C., A.J., V.T. and M.S. performed all experiments, provided material and analysed the results. S.J.C. wrote the manuscript. All authors discussed the results and commented on the manuscript.

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Correspondence to Simon J. Conn.

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The authors declare no competing financial interests.

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Supplementary Information

Supplementary Figures 1–8, Supplementary Table 1, References. (PDF 1203 kb)

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Conn, V., Hugouvieux, V., Nayak, A. et al. A circRNA from SEPALLATA3 regulates splicing of its cognate mRNA through R-loop formation. Nature Plants 3, 17053 (2017). https://doi.org/10.1038/nplants.2017.53

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