Section on Organelle Biology

Head: Jennifer A. Schwartz

 We investigate the global principles underlying secretory membrane trafficking, sorting, and compartmentalization within eukaryotic cells. We use live-cell imaging of green fluorescent protein (GFP) fusion proteins in combination with photobleaching and photoactivation techniques to investigate the subcellular localization, mobility, transport routes, and binding interactions of a variety of proteins with important roles in the organization and regulation of membrane trafficking and compartmentalization. To test mechanistic hypotheses about protein and organelle dynamics, we use quantitative measurements of these protein characteristics in kinetic modeling and simulation experiments. We currently focus on the mechanism of Golgi disassembly and reassembly during mitosis; membrane binding/dissociation kinetics of cytosolic machinery involved in the formation of the coat protein complex COPI and the role of COPI in protein transport through the secretory pathway; the origin and proliferation of peroxisomes; and the compartmentalization of endomembranes in the developing Drosophila embryo. We have also devoted major effort to developing new fluorescence microscopy techniques, in particular a method called photoactivated localization microscopy for imaging fluorescently tagged proteins at near-molecular resolution and a technique called fluorescence protease protection for determining the topology of fluorescently tagged proteins in living cells.

Resources

• Employee Listing
• E-Mail the Lab: lippincj@mail.nih.gov
• SOB Home Page