Abstract: The use of at least one nucleic acid based nuclear localization signal including a natural or synthetic m3G-CAP is shown to increase transmembrane transport of a molecular cargo, in particular large molecules, into the nucleus. The use of natural and synthetic m3G-CAP is disclosed and the effect shown with a natural RNA 5? end nuclear localization signal composed of a 2,2,7-trimethylguanosine CAP (m3G-CAP) coupled to fluorescent Streptavidin in one example, and an antisense oligonucleotide in another. A methylenephosphonate modified m3G-CAP is shown to have improved stability in human serum and in cytosolic extract.

Abstract: The use of at least one nucleic acid based nuclear localization signal including a natural or synthetic m3G-CAP is shown to increase transmembrane transport of a molecular cargo, in particular large molecules, into the nucleus. The use of natural and synthetic m3G-CAP is disclosed and the effect shown with a natural RNA 5? end nuclear localization signal composed of a 2,2,7-trimethylguanosine CAP (m3G-CAP) coupled to fluorescent Streptavidin in one example, and an antisense oligonucleotide in another. A methylenephosphonate modified m3G-CAP is shown to have improved stability in human serum and in cytosolic extract.