Skip to main content
Article thumbnail
Location of Repository

A synthetic snRNA m3G-CAP enhances nuclear delivery of exogenous proteins and nucleic acids

By Pedro M. D. Moreno, Malgorzata Wenska, Karin E. Lundin, Örjan Wrange, Roger Strömberg and C. I. Edvard Smith


Accessing the nucleus through the surrounding membrane poses one of the major obstacles for therapeutic molecules large enough to be excluded due to nuclear pore size limits. In some therapeutic applications the large size of some nucleic acids, like plasmid DNA, hampers their access to the nuclear compartment. However, also for small oligonucleotides, achieving higher nuclear concentrations could be of great benefit. We report on the synthesis and possible applications of a natural RNA 5′-end nuclear localization signal composed of a 2,2,7-trimethylguanosine cap (m3G-CAP). The cap is found in the small nuclear RNAs that are constitutive part of the small nuclear ribonucleoprotein complexes involved in nuclear splicing. We demonstrate the use of the m3G signal as an adaptor that can be attached to different oligonucleotides, thereby conferring nuclear targeting capabilities with capacity to transport large-size cargo molecules. The synthetic capping of oligos interfering with splicing may have immediate clinical applications

Topics: Chemistry and Synthetic Biology
Publisher: Oxford University Press
OAI identifier:
Provided by: PubMed Central

Suggested articles


  1. (2008). A compartmentalized phosphorylation/dephosphorylation system that regulates U snRNA export from the nucleus.
  2. (1999). A nuclear localization signal can enhance both the nuclear transport and expression of 1 kb DNA.
  3. (1999). A peptide nucleic acid-nuclear localization signal fusion that mediates nuclear transport of DNA.
  4. (1990). An essential signaling role for the m3G cap in the transport of U1 snRNP to the nucleus.
  5. (1995). Assembly, nuclear import and function of U7 snRNPs studied by microinjection of synthetic U7 RNA into Xenopus oocytes.
  6. (1986). Cap trimethylation of U snRNA is cytoplasmic and dependent on U snRNP protein binding.
  7. (1996). Chemical synthesis of a 5’-terminal TMG-capped triribonucleotide m(3)(2,2,7)G(5)(’)pppAmpUmpA of U1 RNA.
  8. (2006). Classical nuclear localization signals: definition, function, and interaction with importin alpha.
  9. (2004). Convenient synthesis of nucleoside borane diphosphate analogues: deoxy- and ribonucleoside 5’-P(alpha)-boranodiphosphates.
  10. (1999). Coupling of a targeting peptide to plasmid DNA by covalent triple helix formation.
  11. (1999). Gene delivery: a single nuclear localization signal peptide is sufficient to carry DNA to the cell nucleus.
  12. (1996). Identification of different roles for RanGDP and RanGTP in nuclear protein import.
  13. (2003). Importin beta-depending nuclear import pathways: role of the adapter proteins in the docking and releasing steps.
  14. (2001). In vivo nuclear delivery of oligonucleotides via hybridizing bifunctional peptides.
  15. (2003). Interaction between the small-nuclear-RNA cap hypermethylase and the spinal muscular atrophy protein, survival of motor neuron.
  16. (1982). Karyophilic proteins: polypeptides synthesized in vitro accumulate in the nucleus on microinjection into the cytoplasm of amphibian oocytes.
  17. (2007). Local dystrophin restoration with antisense oligonucleotide PRO051.
  18. (1994). m3G cap hypermethylation of U1 small nuclear ribonucleoprotein (snRNP) in vitro: evidence that the U1 small nuclear RNA-(guanosine-N2)-methyltransferase is a non-snRNP cytoplasmic protein that requires a binding site on the Sm core domain.
  19. (2008). Molecular basis for the recognition of snurportin 1 by importin beta.
  20. (1998). nuclear import of ribosomal proteins in mammalian cells.
  21. (2006). Nuclear import of spliceosomal snRNPs.
  22. (2004). Nuclear localization properties of a conserved protuberance in the Sm core complex.
  23. (2006). Nuclear localizing sequences promote nuclear translocation and enhance the radiotoxicity of the anti-CD33 monoclonal antibody HuM195 labeled with 111In in human myeloid leukemia cells.
  24. (1999). Nuclear targeting peptide scaffolds for lipofection of nondividing mammalian cells.
  25. (2006). One-flask synthesis of dinucleoside tetra- and pentaphosphates.
  26. (1975). Protein migration into nuclei. II. Frog oocyte nuclei accumulate a class of microinjected oocyte nuclear proteins and exclude a class of microinjected oocyte cytoplasmic proteins.
  27. (2004). Purification, crystallization and preliminary crystallographic data of the m3G cap-binding domain of human snRNP import factor snurportin 1. Acta Crystallogr.
  28. (1989). Rapid and efficient synthesis of nucleoside 5’-0-(1-thiotriphosphates), 5’-triphosphates and 2’,3’-cyclophosphorothioates using 2-chloro-4H-1,3,2-benzodioxaphosphorin-4-one.
  29. (1999). Sequence requirements for plasmid nuclear import.
  30. (2002). SMN, the spinal muscular atrophy protein, forms a pre-import snRNP complex with snurportin1 and importin beta.
  31. (2004). snRNAs contain specific SMN-binding domains that are essential for snRNP assembly.
  32. (1998). Snurportin1, an m3G-capspecific nuclear import receptor with a novel domain structure.
  33. (2005). Specific sequence features, recognized by the SMN complex, identify snRNAs and determine their fate as snRNPs.
  34. (2000). Specific sequences of the Sm and Sm-like (Lsm) proteins mediate their interaction with the spinal muscular atrophy disease gene product (SMN).
  35. (2005). Structural basis for m3G-cap-mediated nuclear import of spliceosomal UsnRNPs by snurportin1.
  36. (2007). Structural basis for RanGTP independent entry of spliceosomal U snRNPs into the nucleus.
  37. (1999). Synthesis and reactions of nucleoside 5’-diphosphate imidazolide. A nonenzymatic capping agent for 5’-monophosphorylated oligoribonucleotides in aqueous solution.
  38. (2005). Synthesis of alpha-P-modified nucleoside diphosphates with ethylenediamine.
  39. (1997). The asymmetric distribution of the constituents of the Ran system is essential for transport into and out of the nucleus.
  40. (2002). The importinbeta binding domain of snurportin1 is responsible for the Ran- and energy-independent nuclear import of spliceosomal U snRNPs in vitro.
  41. (1996). The nuclear localization sequence of the SV40T antigen promotes transgene uptake and expression in zebrafish embryo nuclei.
  42. (1997). The SMN-SIP1 complex has an essential role in spliceosomal snRNP biogenesis.
  43. (1998). Up-regulation of luciferase gene expression with antisense oligonucleotides: implications and applications in functional assay development.
  44. (2006). Use of intact Xenopus oocytes in nucleocytoplasmic transport studies.

To submit an update or takedown request for this paper, please submit an Update/Correction/Removal Request.