WCMR Monthly Meetup
Join us on Tuesday, November 28, 2023 for the next WCMR Monthly Meetup with Dr. Nikhil Thomas from Dalhousie University.
Attenuation of an unusual DNA superstructure regulates virulence in pathogenic Vibrio species.
Abstract:
Zoonotic Vibrio species live a dual lifestyle in marine environments as motile, free-living cells and associated with various hosts. Various regulator proteins control gene expression to contextually support host colonization and disease progression. In pathogenic Vibrio species, the conserved HlyU transcriptional regulator is involved in virulence gene regulation. We recently discovered that HlyU acts to attenuate a transcriptional repressive DNA cruciform structure (4-way junction), leading to virulence gene expression in Vibrio parahaemolyticus. Genetic and biochemical experiments revealed an intrinsic chromosomal DNA cruciform formed by constrained DNA supercoiling. The DNA cruciform repressed virulence gene expression presumably by sterically inhibiting requisite transcriptional events. Our data found that HlyU binding to DNA was required to attenuate the cruciform, revealing a non-canonical genetic de-repression mechanism for virulence gene expression. The data highlight a paradigm where a DNA superstructure (and its resolution) impacts on gene expression.
Dr. Nikhil Thomas is a Professor in the Department of Microbiology & Immunology, Division of Infectious Diseases, at Dalhousie University in Halifax. His laboratory emphasizes a cross-disciplinary approach to studying host-pathogen interactions, using techniques in the areas of molecular microbiology, genetics, cell biology, immunology, cell structure, signalling, and protein biochemistry.