1887

Abstract

Viroids of the family , such as eggplant latent viroid (ELVd), contain hammerhead ribozymes and replicate in the chloroplasts of the host plant through an RNA-based symmetrical rolling-circle mechanism in which oligomeric RNAs of both polarity are processed to monomeric linear RNAs (by cleavage) and to monomeric circular RNAs (by ligation). Using an experimental system consisting of transplastomic lines of the alga , a mutational analysis of sequence and structural elements in the ELVd molecule that are involved in transcript processing in a chloroplastic context was carried out. A collection of six insertion and three deletion ELVd mutants was created and expressed in chloroplast. All mutants cleaved efficiently except for the control with an insertion inside the hammerhead ribozyme domain, supporting the prediction that this domain is necessary and sufficient to mediate transcript cleavage . However, two deletion mutants that cleaved efficiently showed ligation defects, indicating that during RNA circularization, other parts of the molecule are involved in addition to the hammerhead ribozyme domain. This is probably a double-stranded structure present in the central part of the molecule which contains the ligation site in an internal loop. However, the mutations prevented the viroid from infecting its natural host, eggplant, indicating that they affected other essential functions in ELVd infectious cycle. The insertion in the terminal loop of the right upper hairpin of ELVd did not have this effect; it was tolerated and partially maintained in the progeny.

Loading

Article metrics loading...

/content/journal/jgv/10.1099/vir.0.013425-0
2009-12-01
2024-04-19
Loading full text...

Full text loading...

/deliver/fulltext/jgv/90/12/3057.html?itemId=/content/journal/jgv/10.1099/vir.0.013425-0&mimeType=html&fmt=ahah

References

  1. Ambrós S., Hernández C., Desvignes J. C., Flores R. 1998; Genomic structure of three phenotypically different isolates of peach latent mosaic viroid: implications of the existence of constraints limiting the heterogeneity of viroid quasispecies. J Virol 72:7397–7406
    [Google Scholar]
  2. Blowers A. D., Bogorad L., Shark K. B., Sanford J. C. 1989; Studies on Chlamydomonas chloroplast transformation: foreign DNA can be stably maintained in the chromosome. Plant Cell 1:123–132 [CrossRef]
    [Google Scholar]
  3. Bock R. 2007; Plastid biotechnology: prospects for herbicide and insect resistance, metabolic engineering and molecular farming. Curr Opin Biotechnol 18:100–106 [CrossRef]
    [Google Scholar]
  4. Boynton J. E., Gillham N. W., Harris E. H., Hosler J. P., Johnson A. M., Jones A. R., Randolph-Anderson B. L., Robertson D., Klein T. M. & other authors; 1988; Chloroplast transformation in Chlamydomonas with high-velocity microprojectiles. Science 240:1534–1538 [CrossRef]
    [Google Scholar]
  5. Branch A. D., Robertson H. D. 1984; A replication cycle for viroids and other small infectious RNAs. Science 223:450–455 [CrossRef]
    [Google Scholar]
  6. Branch A. D., Robertson H. D., Greer C., Gegenheimer P., Peebles C., Abelson J. 1982; Cell-free circularization of viroid progeny RNA by an RNA ligase from wheat-germ. Science 217:1147–1149 [CrossRef]
    [Google Scholar]
  7. Bussière F., Lehoux J., Thompson D. A., Skrzeczkowski L. J., Perreault J. P. 1999; Subcellular localization and rolling circle replication of peach latent mosaic viroid: hallmarks of group A viroids. J Virol 73:6353–6360
    [Google Scholar]
  8. Canny M. D., Jucker F. M., Pardi A. 2007; Efficient ligation of the Schistosoma hammerhead ribozyme. Biochemistry 46:3826–3834 [CrossRef]
    [Google Scholar]
  9. Côté F., Perreault J. P. 1997; Peach latent mosaic viroid is locked by a 2′,5′-phosphodiester bond produced by in vitro self-ligation. J Mol Biol 273:533–543 [CrossRef]
    [Google Scholar]
  10. Côte F., Lévesque D., Perreault J. P. 2001; Natural 2′,5′-phosphodiester bonds found at the ligation sites of peach latent mosaic viroid. J Virol 75:19–25 [CrossRef]
    [Google Scholar]
  11. Daròs J. A., Flores R. 2002; A chloroplast protein binds a viroid RNA in vivo and facilitates its hammerhead-mediated self-cleavage. EMBO J 21:749–759 [CrossRef]
    [Google Scholar]
  12. Daròs J. A., Flores R. 2004; Arabidopsis thaliana has the enzymatic machinery for replicating representative viroid species of the family Pospiviroidae . Proc Natl Acad Sci U S A 101:6792–6797 [CrossRef]
    [Google Scholar]
  13. Daròs J. A., Marcos J. F., Hernández C., Flores R. 1994; Replication of avocado sunblotch viroid: evidence for a symmetric pathway with two rolling circles and hammerhead ribozyme processing. Proc Natl Acad Sci U S A 91:12813–12817 [CrossRef]
    [Google Scholar]
  14. Daròs J. A., Elena S. F., Flores R. 2006; Viroids: an Ariadne's thread into the RNA labyrinth. EMBO Rep 7:593–598 [CrossRef]
    [Google Scholar]
  15. Ding B. 2009; The biology of viroid-host interactions. Annu Rev Phytopathol 47:105–131 [CrossRef]
    [Google Scholar]
  16. Englert M., Latz A., Becker D., Gimple O., Beier H., Akama K. 2007; Plant pre-tRNA splicing enzymes are targeted to multiple cellular compartments. Biochimie 89:1351–1365 [CrossRef]
    [Google Scholar]
  17. Fadda Z., Daròs J. A., Fagoaga C., Flores R., Duran-Vila N. 2003a; Eggplant latent viroid , the candidate type species for a new genus within the family Avsunviroidae (hammerhead viroids). J Virol 77:6528–6532 [CrossRef]
    [Google Scholar]
  18. Fadda Z., Daròs J. A., Flores R., Duran-Vila N. 2003b; Identification in eggplant of a variant of citrus exocortis viroid (CEVd) with a 96 nucleotide duplication in the right terminal region of the rod-like secondary structure. Virus Res 97:145–149 [CrossRef]
    [Google Scholar]
  19. Fedor M. J. 2000; Structure and function of the hairpin ribozyme. J Mol Biol 297:269–291 [CrossRef]
    [Google Scholar]
  20. Flores R., Daròs J. A., Hernández C. 2000; The Avsunviroidae family: viroids containing hammerhead ribozymes. Adv Virus Res 55:271–323
    [Google Scholar]
  21. Flores R., Hernández C., Martínez de Alba A. E., Daròs J. A., Di Serio F. 2005; Viroids and viroid-host interactions. Annu Rev Phytopathol 43:117–139 [CrossRef]
    [Google Scholar]
  22. Harris E. H. 2001; Chlamydomonas as a model organism. Annu Rev Plant Physiol Plant Mol Biol 52:363–406 [CrossRef]
    [Google Scholar]
  23. Haseloff J., Mohamed N. A., Symons R. H. 1982; Viroid RNAs of cadang-cadang disease of coconuts. Nature 299:316–321 [CrossRef]
    [Google Scholar]
  24. Hertel K. J., Herschlag D., Uhlenbeck O. C. 1994; A kinetic and thermodynamic framework for the hammerhead ribozyme reaction. Biochemistry 33:3374–3385 [CrossRef]
    [Google Scholar]
  25. Hutchins C. J., Keese P., Visvader J. E., Rathjen P. D., McInnes J. L., Symons R. H. 1985; Comparison of multimeric plus and minus forms of viroids and virusoids. Plant Mol Biol 4:293–304 [CrossRef]
    [Google Scholar]
  26. Kikuchi Y., Tyc K., Filipowicz W., Sänger H. L., Gross H. J. 1982; Circularization of linear viroid RNA via 2′-phosphomonoester, 3′,5′-phosphodiester bonds by a novel type of RNA ligase from wheat-germ and Chlamydomonas . Nucleic Acids Res 10:7521–7529 [CrossRef]
    [Google Scholar]
  27. Malfitano M., Di Serio F., Covelli L., Ragozzino A., Hernández C., Flores R. 2003; Peach latent mosaic viroid variants inducing peach calico (extreme chlorosis) contain a characteristic insertion that is responsible for this symptomatology. Virology 313:492–501 [CrossRef]
    [Google Scholar]
  28. Molina-Serrano D., Suay L., Salvador M. L., Flores R., Daròs J. A. 2007; Processing of RNAs of the family Avsunviroidae in Chlamydomonas reinhardtii chloroplasts. J Virol 81:4363–4366 [CrossRef]
    [Google Scholar]
  29. Navarro B., Flores R. 1997; Chrysanthemum chlorotic mottle viroid: unusual structural properties of a subgroup of self-cleaving viroids with hammerhead ribozymes. Proc Natl Acad Sci U S A 94:11262–11267 [CrossRef]
    [Google Scholar]
  30. Navarro J. A., Daròs J. A., Flores R. 1999; Complexes containing both polarity strands of avocado sunblotch viroid: identification in chloroplasts and characterization. Virology 253:77–85 [CrossRef]
    [Google Scholar]
  31. Nelson J. A., Shepotinovskaya I., Uhlenbeck O. C. 2005; Hammerheads derived from sTRSV show enhanced cleavage and ligation rate constants. Biochemistry 44:14577–14585 [CrossRef]
    [Google Scholar]
  32. Rakowski A. G., Symons R. H. 1989; Comparative sequence studies of variants of avocado sunblotch viroid. Virology 173:352–356 [CrossRef]
    [Google Scholar]
  33. Rodio M. E., Delgado S., Flores R., Di Serio F. 2006; Variants of Peach latent mosaic viroid inducing peach calico: uneven distribution in infected plants and requirements of the insertion containing the pathogenicity determinant. J Gen Virol 87:231–240 [CrossRef]
    [Google Scholar]
  34. Rodio M. E., Delgado S., De Stradis A., Gómez M. D., Flores R., Di Serio F. 2007; A viroid RNA with a specific structural motif inhibits chloroplast development. Plant Cell 19:3610–3626 [CrossRef]
    [Google Scholar]
  35. Semancik J. S., Szychowski J. A., Rakowski A. G., Symons R. H. 1994; A stable 463-nucleotide variant of citrus exocortis viroid produced by terminal repeats. J Gen Virol 75:727–732 [CrossRef]
    [Google Scholar]
  36. Suay L., Salvador M. L., Abesha E., Klein U. 2005; Specific roles of 5′ RNA secondary structures in stabilizing transcripts in chloroplasts. Nucleic Acids Res 33:4754–4761 [CrossRef]
    [Google Scholar]
  37. Zuker M. 2003; Mfold web server for nucleic acid folding and hybridization prediction. Nucleic Acids Res 31:3406–3415 [CrossRef]
    [Google Scholar]
http://instance.metastore.ingenta.com/content/journal/jgv/10.1099/vir.0.013425-0
Loading
/content/journal/jgv/10.1099/vir.0.013425-0
Loading

Data & Media loading...

Supplements

Supplementary material 1

PDF
This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error