- Bachelor of Arts, Princeton University, 1989
- Doctor of Philosophy, Univ California San Francisco, 1997
Professor Romberg is a member of the Department of Biology and an affiliate of the Department of Chemistry and Biochemistry.
Specialties: bacterial cell division, the biochemistry of the cytoskeleton
Research: The increasing prevalence of drug-resistant bacteria has resulted in searches for new antibiotics. Penicillin inhibits bacterial elongation, but cell division is another potential target that is now being explored. A protein called FtsZ is essential for bacterial cell division and may make a good antibiotic target; it is present in nearly all bacterial species but is absent in humans. As a result, inhibiting FtsZ function could prevent bacteria from dividing without causing side effects due to interactions with human proteins.
FtsZ is a distant homolog of eukaryotic tubulin and polymerizes to form part of the bacterial cytoskeleton. Like the musculoskeletal system of our own bodies, a cell's cytoskeleton determines its shape and can produce force. However, unlike the bones in a skeleton, the structures in the cytoskeleton are transient. The cytoskeleton as a whole is maintained through continual, carefully balanced polymer assembly and disassembly. Understanding FtsZ's polymer dynamics will aid the development of drugs that can disrupt FtsZ structures and thereby prevent cell division.
In cells, FtsZ assembles into a ring at the future site of cell division. This ring is highly dynamic and can rapidly assemble, relocalize, constrict, and disassemble. Ring dynamics are due to the reversibility of FtsZ polymerization; like microtubules, FtsZ polymers assemble in the presence of GTP but tend to curve and disassemble after the GTP has been hydrolyzed.
It is unknown whether FtsZ exhibits the complex, cooperative behaviors of tubulin, including 1) nucleated assembly: the establishment of new polymers is less favorable than growth from pre-established polymers, and 2) dynamic instability: at steady state, individual polymers undergo abrupt transitions between steady growth and rapid shrinkage. My lab is addressing two major questions:1) At what level of assembly does cooperative polymerization emerge? 2) How is FtsZ polymerization promoted or inhibited by its interactions with other proteins?
Teaching: I teach an upper level courses in Microbiology (Biol 306/307) and an advanced seminar in Prokaryotic Cell Biology (Biol 403). I also teach Cell and Molecular Biology (Biol 213/214) and will probably teach a first year seminar on the science of food and cooking.
Outside of my teaching and research, I enjoy swimming, biking, going to art exhibits and art movies, and eating ethnic foods.