Hyperactive Himar1 Transposase Mediates Transposition in Cell Culture and Enhances Gene Expression In Vivo

The use of nonviral delivery systems results in transient gene expression, in part because of the low efficiency of DNA integration. Previously, vectors based on transposon systems such as Sleeping Beauty have been shown to be able to increase stable transfection efficiencies in cell culture and in animal models. Himar1, a reconstructed active transposon belonging to the Tc1/mariner superfamily, also has been used as a vector for stable gene delivery, but the rate of transposition after transfection is low. In this paper, we evaluate the potential of the hyperactive Himar1 transposase C9, in combination with the Himar1 inverted repeat transposon, as a gene delivery vector. The C9 transposase is a hyperactive mutant of Himar1 with two amino acid substitutions, Q131R and E137K, that result in an increase in activity relative to wild type. Here we demonstrate that cotransfection of the C9 transposase with a Himar1-based vector increases the frequency of stable gene expression in human cells in a transposase ...