Professor

Microbiology

Cornell University (Ithaca, NY)

Our laboratory studies regulatory proteins that modulate transcription in response to environmental stress in Bacillus subtilis.

Our laboratory focuses on environmental stress responses in Bacillus subtilis. One project addresses the roles of alternative sigma factors that redirect RNA polymerase to express new sets of genes. For example, the Sigma-W and Sigma-M regulons are activated in response to cell wall biosynthesis inhibitors, such as vancomycin, and include genes that protect the cell against antimicrobial agents. The Sigma-X regulon includes genes that modulate the cell surface charge and affect resistance to antimicrobials and cationic peptides. Another area of interest is the regulation of gene expression by metal ions (particularly iron and zinc) and reactive oxygen species. Remarkably, B. subtilis contains three distinct Fur homologs that control gene expression in response to specific transition metals. Iron uptake systems are repressed by Fur while Zur controls genes responsible for zinc uptake. The third Fur homolog, PerR, controls genes for peroxide resistance and this regulon is expressed in response to hydrogen peroxide. In related studies, we are investigating the role of OhrR in the regulation of gene expression in response to organic peroxide stress.

2007 Division J Lecturer: ASM Annual Meeting

1993 Vector Laboratories Young Investigator Award, ASM

1988-1990 Jane Coffin Childs Post-Doctoral Fellowship

1982 Achievement Reward for College Scientists (ARCS)