alpha-complementation-enabled T7 expression vectors and their use for the expression of recombinant polypeptides for protein transduction experiments.

Over the past few years protein transduction has emerged as a powerful means for the delivery of proteins into cultured cells and into whole mice. This method is based on the ability of proteins containing protein transduction domains (PTDs), short stretches of 9-16 predominantly basic amino acids, to traverse the cytoplasmic membrane and accumulate inside cells in a time- and dose-dependent fashion. The number of PTDs, both natural and synthetic, is constantly expanding, as is the need to test newly discovered PTDs for their ability to mediate the internalization of the corresponding fusion proteins. Here we describe a strategy and methodology that can be used for the construction of vectors for the T7 RNA polymerase-driven expression of PTD fusions. The cloning in these vectors is facilitated by alpha-complementation. Also, these vectors are small in size (less than 3 kbp) and express influenza virus hemagglutinin tag as well as His tag as part of the fusion for immunological identification and purification respectively of expressed proteins.