Characterization of the cell biology of bacterial membrane synthesis.

Abstract

Even though the enzymology of membrane synthesis is well understood, much less is known about the spatial and topological aspects of this process. Biochemistry can only be completely understood if the reactions are properly placed in the context of the subcellular structures where they take place. One important unanswered question in this area is whether membrane synthesis is a localized or dispersive process, in particular during cell division, a time when the bacterial envelope has to grow specifically at the site of septation. Given the conflicting results in the literature regarding this issue, we propose to carry out a thorough and rigorous reinvestigation of the cell biology of the main phospholipid synthesis enzymes PlsX, PlsY and PlsC. This will include the generation of new and optimized fluorescent protein fusions and the application of state of the art microscopy techniques such as single molecule tracking and Super Resolution Radial Fluctuation (SRRF) imaging. This aim will be carried out in collaboration with Dr. Ethan Garner (Harvard MCB Department), whose group is renowned for the application of sophisticated imaging methods to solve fundamental bacterial cell biology questions. In addition to the investigation of the basic cell biological features of bacterial membrane biogenesis, the postdoctoral fellow selected for this fellowship will also be in charge of validating PlsX, a key regulatory enzyme of phospholipid synthesis, as an antibiotic target. This will entail developing and executing small molecule and natural product screens for inhibitors of this promising new antibiotic target.