- Professor, Molecular Genetics and Cell Biology. Committees on Genetics, Microbiology, and Cell Physiology
- A.B. Biochemistry, Harvard University, 1981
- Ph.D. Biochemistry and Molecular Biology, Harvard University, 1988
University of Chicago
920 E. 58th St.
Chicago, IL 60637
Phone: (773) 702-4374
Fax: (773) 702-3172
Our laboratory studies membrane traffic in the ciliate Tetrahymena thermophila, a eukaryotic microbe. Ciliates emerged as an early branch during eukaryotic evolution, and are far more distantly related to humans, for example, than are most organisms being studied by cell biologists. Our interest in these cells stems from the fact that ciliates are unicellular and offer a host of experimental advantages, but at the same time are highly complex and maintain many cellular features that are usually associated with animal cells. In particular, ciliates have a prominent pathway for regulated secretion of polypeptides via dense core granules. Such granules arise by mechanisms that are poorly understood in the mammalian cells in which they have classically been studied. We use a combination of biochemical and genetic approaches, taking advantage of the ability to derive viable Tetrahymena mutants with defects in granule function. Our second major interest is in the "opposite" process, endocytosis, by which membrane is taken up from the cell surface. Ciliates also appear to maintain endocytic structures that are remarkably similar to those in animal cells, yet differences at the molecular level, first suggested by analysis of the Tetrahymena genome, are turning out to be informative both for mechanistic and evolutionary studies.