Daniel Nickerson

Molecular Signaling at Intracellular Membranes.
Eukaryotic cells use membranes to divide up their interior space into compartments (organelles) that provide appropriate microenvironments for specific biochemical functions.
Many textbooks and reviews describe membrane compartments in cells as 'discrete,' but that word also implies isolation or disconnection. In fact, 'discrete' organelles are gregarious, consistently bumping into one another, forming stable or transient docking sites to exchange materials and interrogate one another. When membranes possess compatible fusion factors (SNAREs, SM proteins and Rab GTPases), the steep energetic barrier preventing membrane fusion can be overcome and the compartments merge. Several layers of quality control govern when and whether docked membranes fuse.
I seek to understand how separate membranes in cells can meet, communicate, swap components, and how the identities of compartments are either maintained or adjusted as circumstances demand. Rab GTPases perform a central role in mediating compartmental interactions and membrane transport, and the yeast Saccahromyces cerevisiae is the ideal system, both genetically and biochemically, for exploring novel cellular functions and regulatory mechanisms for Rabs. I also use yeast as a platform for developing new cellular probes and diagnostics, such as the quantitative endocytic transport assay, LUCID (Luciferase assay of Intraluminal Deposition). Importantly, my research interests and experimental system are immediately accessible to early stage trainees, with opportunities for undergraduate and masters students interested in molecular and cell biology, biochemistry, microbiology and biotechnology, as well as classical and modern genetic analyses.