John Whitney
Assistant Professor, Biochemistry & Biomedical Sciences
(905) 525-9140 x 22280

Research in the Whitney Lab seeks to understand the molecular mechanisms that underlie microbe-microbe interactions.

Interbacterial Killing - By The Type VI Secretion System The bacterial type VI secretion system is a recently identified protein translocation pathway used by Gram-negative bacteria to deliver toxins to neighbouring bacteria in a cell contact-dependent manner. The Whitney Lab is interested in understanding how these antibacterial proteins are transported from one cell to another and how they exert toxicity once delivered to a target cell.

Type VII Secretion-dependent Interbacterial Antagonism - In contrast to their Gram-negative counterparts, the pathways involved in interbacterial antagonism between Gram-positive bacteria has long remained elusive. In recent work, the Whitney Lab and others have found that the type VII secretion system exports antibacterial toxins that mediate interbacterial competition. Elucidating the mode of action of these toxins will allow for the identification of new vulnerabilities in Gram-positive cells that can be exploited for the development of new antibiotics.

Exopolysaccharide Secretion and Interbacterial Adhesion - Many species of bacteria exist in dense cellular aggregates held together by bacterially produced exopolysaccharides. In this form, bacteria are difficult to eradicate due in part to decreased efficacy of antibiotics. The Whitney Lab is interested in determining how bacterial exopolysaccharides are synthesized and exported from the cell.