title: Factors influencing the ability of nuclear localization sequence peptides to enhance nonviral gene delivery.
abstract: Nonviral gene delivery is limited by inefficient transfer of DNA from the cytoplasm to the nucleus. Nuclear localization sequence (NLS) peptides have been widely used to exploit intracellular transport mechanisms and promote nuclear uptake of DNA. However, the exact conditions to successfully utilize the properties of NLS peptides are still unclear. In the present study a panel of NLS peptides that bind different transport receptors were compared for their ability to enhance nonviral gene transfer. Several factors such as method of incorporating the NLS peptide, type of NLS peptide, DNA morphology, and proper characterization of NLS peptide/DNA conjugates were identified as important considerations in utilizing NLS peptides to enhance gene transfer. In particular, it was shown that a peptide derived from human T cell leukaemia virus type 1 (HTLV) was able to effectively condense DNA into discrete particles and mediate levels of transgene expression up to 32-fold greater than polylysine-based polyplexes. This is the first study to demonstrate efficient transfection mediated by an importin beta-binding peptide based on the HTLV sequence. Promising results were also achieved with a 7-fold increase in gene expression using a NLS peptide/DNA conjugate formed by site-specific linkage of an extended SV40 peptide via a peptide nucleic acid (PNA) clamp. Altogether, the results from this study should help to define the requirements for successful NLS-enhanced transfection.
authors.affiliation: Cancer Research UK Institute for Cancer Studies, University of Birmingham, Birmingham, B15 2TH, UK.
authors.forename: K Helen
authors.initials: KH
authors.lastname: Bremner
authors.forename: Leonard W
authors.initials: LW
authors.lastname: Seymour
authors.forename: Ann
authors.initials: A
authors.lastname: Logan
authors.forename: Martin L
authors.initials: ML
authors.lastname: Read
mesh_terms: D000595:Amino Acid Sequence; D002470:Cell Survival / Q000187:drug effects / Q000235:genetics; D004247:DNA / Q000737:chemistry* / Q000187:drug effects / Q000235:genetics; D015870:Gene Expression / Q000187:drug effects; D018014:Gene Transfer Techniques; D017930:Genes, Reporter / Q000235:genetics; D005982:Glutathione Transferase / Q000235:genetics; D006367:HeLa Cells; D006801:Humans; D028884:Karyopherins / Q000737:chemistry; D008301:Maleimides / Q000737:chemistry; D008969:Molecular Sequence Data; D019913:Nuclear Localization Signals / Q000235:genetics*; D010455:Peptides / Q000737:chemistry / Q000494:pharmacology*; D010957:Plasmids / Q000235:genetics; D018160:Receptors, Cytoplasmic and Nuclear / Q000187:drug effects; D011993:Recombinant Fusion Proteins; D014162:Transfection
chemical_list: D028884:Karyopherins; D008301:Maleimides; D019913:Nuclear Localization Signals; D010455:Peptides; D018160:Receptors, Cytoplasmic and Nuclear; D011993:Recombinant Fusion Proteins; D004247:DNA; D005982:Glutathione Transferase