Protein Therapy: in vivo protein transduction by polyarginine (11R) PTD and subcellular targeting delivery.

Protein Therapy is a newly developed method, which allows proteins, peptides and biologically active compounds to penetrate across the plasma membrane of eukaryotic cells by a polyarginine (most efficiently by 11-arginine, 11R) protein transduction domain. This method enables us to control the localization of targeted substances in subcellular compartments, such as the nuclei, mitochondria and post-synaptic density. The method is very efficient and applicable not only to cultured cells but also to tissue slices and the whole animal. Brain, heart, skeletal muscle, liver, pancreas and lymphocytes are efficient target organs and tissues for Protein Therapy. The method is therefore a very useful strategy in the post-genomic era. In this mini-review, the development of Protein Therapy and its application for cancer cells and neuroscience study will be shown.