Detailed Biography:

Intercellular junctions and communication

A fundamental property of cells organized in tissues is their ability to communicate with ech other via highly specialized areas of plasma membrane contact, called junctions. We are studying the gap junction and the chemical synapse, two specialized junctions that mediate electrical and chemical transmission, respectively. The gap junction is composed of specialized channels containig small hydrophilic pores that span the two plasma membranes and the intervening extracellular space (the cell-to-cell channel). We are investigating the high resolution structure of the channels as well as the mechanisms of assembly, insertion and retrieval of the connexin proteins which form them. The chemical synapse is composed of a presynaptic neuron filled with small diameter vesicles that contain high concentration of neurotransmitters and a postsynaptic neuron with receptors. We are studying the mechanisms by which the synaptic vesicles attach ("dock") to the presynaptic membrane. We use structural (electron microscopy), biochemical and electrophysiological techniques in an attempt to identify, purify and characterize the channels and transporters of both junctions in an effort to further understand the mechanisms mediating cell communication.