Multicolor and time-resolved electron microscopy of cell signaling

My laboratory will develop new biophysical methods to investigate the nanoscale cellular organization of G protein-coupled receptors (GPCRs), which form the largest and the most pharmacologically targeted class of transmembrane receptors in humans.

1. Multicolor electron microscopy:

We will develop a method for single-molecule multicolor electron microscopy that uses inorganic nanoparticles as luminescent protein tags. Under excitation by an electron beam, these nanoparticles emit light via a process known as cathodoluminescence. This technology will permit observation of both the cellular ultrastructure and individual proteins with nanoscale resolution in a single experiment. We will use this method to study how cellular membrane ultrastructure controls the compartmentalization of GPCR signaling in complex tissues such as the heart and the brain.

2. Time-resolved vitrification:

Cell signaling involves orchestrated nanoscale motions of proteins and membranes triggered by a stimulus (e.g. addition of a drug). However, nanoscale imaging techniques lack the temporal resolution necessary to observe these motions. To recover this temporal information, we will develop methods that will allow vitrifying biological samples at ultrafast time delays following stimulation for subsequent super-resolved optical and electron imaging. Using these methods, we will elucidate the time course of nanoscale molecular interactions involved in GPCR signaling in cells derived from iPSCs and animal models.