The present invention relates to polypeptide for engineering integrase chimeric proteins and their use in gene therapy.
A key challenge for gene transfer based on the use of retroviral vectors is to achieve stable transgene expression while minimizing insertional mutagenesis and induction of the DNA damage response due to the presence of double stranded DNA. One approach to avoid insertional mutagenesis is to target the transgene integration to a specific location on the genome.
Here autors describe an interaction between Ty1 integrase and the AC40 subunit of Pol III and demonstrate that AC40 is the predominant determinant targeting Ty1 integration upstream of Pol III–transcribed genes. Lack of an integrase-AC40 interaction dramatically alters target site choice, leading to a redistribution of Ty1 insertions in the genome, mainly to chromosome ends. The mechanism of target specificity allows Ty1 to proliferate and yet minimizes genetic damage to its host. Accordingly, the domain of Ty1 responsible for the interaction with the RNA polymerase III is suitable to engineering integrase of retrovirus so as to drive the targeted integration of a transgene into a eukaryotic genome.