PROTLEGO (260647)

  https://cordis.europa.eu/project/id/260647

  FP7 (2007-2013)

  Development of an accessible platform for ex vivo site specific post-translational modifications of proteins

  ERC Starting Grant - Applied life sciences and biotechnology (ERC-SG-LS9)

  proteins  ·  amines

  2010-10-01 Start Date (YY-MM-DD)

  2016-03-31 End Date (YY-MM-DD)

  € 1,398,000 Total Cost

  Description

The incorporation of unnatural amino acids (more than 50 to date) into proteins in vivo has resulted in the generation of proteins with novel chemical, biological, and physical properties. However, some unnatural amino acids possess properties, such as an inability to cross the cell membrane or a level of toxicity dangerous to the organism, that restrict their incorporation into proteins in vivo. In addition, even when an unnatural amino acid crosses the cell membrane, its transport efficiency within the cell is very low. We propose to overcome these limitations by exploiting translational components evolved tRNA-synthetases and their cognate suppressor-tRNA from Archea for the incorporation of an array of unnatural amino acids into proteins in vitro in a cell-free protein translation system. The expressed recombinant proteins containing the unnatural amino acids will be purified from the reaction mixture and used for further research. Using the cell free system, first we will demonstrate our new approach by incorporating novel unnatural amino acids, i.e., thiolysine analogues, into proteins using the broad substrate specificity of evolved tRNA synthetases. We will then incorporate a thiolysine analogue into PCNA for the site-specific ubiquitination and SUMOylation of these proteins for in vitro studies of the interactions between PCNA and interacting proteins and to follow the progress of the replication fork. This unique approach will show for the first time the use of evolved synthetases in a cell free translation system, with the advantage being that previously un-incorporable unnatural amino acids can be incorporated using this approach. Our overall aim is to enable the introduction of new functionalities into proteins.

  Complicit Organisations

1 Israeli organisation participates in PROTLEGO.