Sleeping Beauty transposon inverted terminal repeat direct repeats (SB ITR DRs)

The Sleeping Beauty (SB) transposon inverted terminal repeat (ITR) direct repeats (DRs) are essential DNA recognition sequences that define the boundaries of the SB transposon system. These sequences are specifically recognized and bound by the Sleeping Beauty transposase, an enzyme that facilitates the "cut-and-paste" movement of genetic material (Ivics et al., 1997). Each ITR contains two DRs—an inner and an outer repeat—which are necessary for the formation of a functional synaptic complex during the transposition process (Izsvák et al., 2000). In the context of modern biotechnology, these sequences are engineered into plasmids to deliver therapeutic genes, such as those encoding chimeric antigen receptors (CARs), into human cells (Hudecek et al., 2010). This non-viral approach offers a cost-effective alternative to viral vectors for stable gene modification in immunotherapy and gene therapy. The interaction between the transposase and the DRs ensures that only the DNA flanked by the ITRs is excised and integrated into the host genome. However, the integration process is semi-random, occurring primarily at TA dinucleotides, which poses a theoretical risk of insertional mutagenesis if the transposon disrupts critical regulatory regions (Narayanavari & Izsvák, 2017).

Other names

SB ITRsSleeping Beauty direct repeatsSB-DRsInverted terminal repeats of Sleeping BeautySB transposon ends

The Sleeping Beauty transposase recognizes and binds to the direct repeat (DR) sequences within the inverted terminal repeats (ITRs), facilitating the excision of the transposon from a donor plasmid and its subsequent integration into the host cell genome at TA dinucleotide sites.