Real Time Monitoring of Signaling Pathways in Biological Cells

Cell function and survival are dictated by the transduction of the appropriate signaling pathways within the cell. These signaling pathways regulate nearly every aspect of cellular function from growth and proliferation, to progammed cell death, and sensing the surrounding environment. Until recently, investigation of cellular pathways has relied on destructive or after-the-fact techniques, including probing cell lysate for changes after a particular agonist has been added to the cell culture, or inferring protein activity in a pathway based on downstream events. We propose to investigate, in real time and in vivo, cellular pathways with a nanoprobe that can release or capture an enzyme or protein on demand. This probe is based on TiO2 nanoparticles, which are photoexcitable in the UV-range, and are attached to a molecular wire, through which this excitation can be harnessed. With modifications to this nanoprobe, it should be possible also to regulate gene transcription and use the nanoprobe in a biosensor platform to monitor the environment or solutions (including biologically-based solutions) for chemical or biological weapons.