Intracellular Biophotonic Nanoswitches

Recent mapping of all physical interactions between proteins in a given cell has confirmed the notion that interactions between proteins are highly regulated and underpin all cellular processes. Researchers and technologists have been presented with a major challenge - how to ask specific questions of such complex systems especially when protein interactions change with time in a given cell and result in different end states. For example when a human cell responds to stress, specific interactions between master regulatory proteins start to drive a recovery process or initiate a controlled commitment to cell death. This project aims to generate a generic technology for solving this problem - introducing synthetic switches into live cells that can 'fine-tune' protein interactions by remote control. This exciting approach, based on highly promising preliminary work, would allow the investigator to programme changes in defined protein-protein interactions by the introduction of small interfering molecules engineered to be switched on and off by light of carefully selected wavelengths. Changes in the structure of a small molecule are triggered by external light pulses inducing conformational rearrangements in the peptide backbone and hence alterations of the biological properties of the Intracellular Biophotonic Nanoswitch (IBN). IBNs are light-sensitive nanoparticle-based molecular structures linked to the short peptide sequences that recognize features on the surface of a protein that has been targeted for switching. Conventional and novel methods for IBN delivery into live cells will allow patterning of the swiches into populations of cells. Operating these IBNs by light will allow the researcher to pattern the activation of switches in such complex cell populations or to 'programme' the switching process in single cells - a step-forward in the technology of manipulating master regulators of discrete intracellular pathways. Our proposal's adventure and risk relates to the problems of IBN design and their potential for self-reporting in live cells.IBNs will allow a researcher to switch or programme the state of a master regulator in a live cell by biophysical means and explore the consequences on the whole system to reveal the internal linking of different pathways. Furthermore, our proposal addresses how to track the downstream consequences of selective switching, even in different lineages, to reveal how cells respond to different signals (amplitude or frequency) in developing their responses even if these arise quickly or indeed develop slowly through different cell generations.Since our vision is to provide the life sciences community with novel, robust and readily implemented technologies based on robust chemical systems, the proposal encompasses engagement with potential user & downstream demands of IBN technology with a focus on the burgeoning demand to understand cellular biology at the complex 'systems' level. The exciting prospect looms of gaining programmable photonic control over normal physiology (directing stem cell differentiation, manipulating wound healing and delaying cell senescence), neoplasia (cancer biology of cell cycle checkpoint dysfunction and photonically-controlled therapeutics), constructed cell communities (light-directed tissue engineering) and molecular target identification (the search for new medicines and products).