In the brain, astrocytes are essential cells that govern the formation and elimination of synapses between neurons. The exact mechanisms of how astrocytes interact with neurons remains elusive—mostly due to the lack of tools to study it in live cells. We report the design and use of a set of molecular probes to visualize, label, and influence proteins in their native environment.
Organic synthesis leads our chemical biology program. We have identified natural products displaying exquisite selectivity for proteins involved in neuro-glial communication and have modified them to use as molecular tools. For example, we target the following proteins: ionotropic glutamate receptors sensitive to kainic acid (GluK), voltage-gated calcium channels (CaV1.x), integrin alphaVbeta5 (ITGaVb5), and milk-fat globulin E8 (MFG-E8). The corresponding ligands include: kainic acid, cilengitide, and phosphatitdylserine.
The ligands were initially conjugated with fluorescent tags to enable the study of the proteins in living cells. We then characterize the dynamics of signaling events in cultured cells using combined imaging and electrophysiology techniques. Advantages of our approach is the time saved by not using genetic modifications. With the help of these molecules, we can start to deconvolute the microscopic events underpinning the communication between neurons and glia.