The goal of this project is to understand how membrane protein localization controls and is controlled by cell division. I hypothesize that localization of essential protein machinery is central to microbial growth and that inhibition of protein localization is a valid avenue for the development of new antibiotics. As such, a mechanistic understanding of how bacteria localize, regulate and utilize essential protein complexes is material to the development of translational products. In particular, I have focused on three classes of membrane proteins: outer membrane Bam proteins (both lipoproteins and beta-barrel proteins) and inner membrane, band 7 domain proteins. The Bam machine inserts beta-barrel proteins into the bacterial outer membrane and is essential for growth. Band 7 proteins are homologous to eukaryotic membrane raft-associated reggie/flotillin proteins and, I hypothesize, integral to the control of an essential membrane protease. In both cases, I will utilize chimeras between these proteins and fluorescent reporters to understand where and how they are localized in accordance with the progression of cell differentiation, growth and division in the bacterium Caulobacter crescentus. I will complement localization experiments with studies designed to chemically or genetically deplete specific components essential to cell division in order to discover the role of these membrane proteins in the circuit of protein localization driving an asymmetric cell cycle. A comprehensive understanding of these molecules will be an important tool in designing screening platforms to discover new agents against emerging and re-emerging pathogens.
Antibiotic-resistance amongst emerging and re-emerging bacterial pathogens, particularly amongst nosocomial infections, is a serious threat to public health in the United States. Some aggressive bacterial pathogens have acquired resistance to all antimicrobial countermeasures and, therefore, the development of new classes of antibiotic therapy is paramount. By studying essential microbial processes not yet the target of therapeutics, we aim to inform the development of novel countermeasures.
|Blair, Jimmy A; Xu, Qingping; Childers, W Seth et al. (2013) Branched signal wiring of an essential bacterial cell-cycle phosphotransfer protein. Structure 21:1590-601|