Transductin, licensed from Traversa Therapeutics for research applications, is intended for in vitro testing and high-throughput screening projects. Transductin complexes with dsRNAs, such as IDT’s Dicer-substrate siRNAs, and delivers them across cell membranes via macropinocytosis. This mechanism minimizes the risk of having the dsRNA trigger an innate immune response and has virtually no toxicity, which are common drawbacks when using cationic lipid transfection. ‘As a result’, Dr Mark Behlke, IDT’s Chief Scientific Officer, commented, ‘Transductin enables delivery of dsRNAs (such as siRNAs) to almost all cell types, including those that are traditionally difficult to transfect such as JAWSII and PC12’.
Developed by Dr Steven Dowdy’s lab at the UCSD School of Medicine [1], Transductin is a small fusion protein comprised of multiple peptide transduction domains connected to a double-stranded RNA-binding domain (PTD–DRBD). The DRBD domain binds the RNA duplex and serves to keep the positively charged PTDs away from the negatively charged RNA, maximizing potency of the peptide transduction domain. Dr.Behlke concluded, ‘By combining Transductin with Dicer-substrate siRNAs, RNA interference can now be achieved with virtually any cell type, including primary cells and human stem cells, with lower off-target effects. This also means that the cell state is less likely to be affected and any resultant effects are due directly to the knockdown of the gene of interest increasing experimental accuracy’.
References
1 Eguchi, A., et al. (2009) Efficient siRNA delivery into primary cells by a peptide transduction domain–dsRNA binding domain fusion protein. Nature Biotechnology 27, 567–571