EAGER: Evaluation of an in silico constructed transcriptional regulatory network

University Of Southern California, Los Angeles CA

Investigators

Abstract

Intellectual merit: Shewanella oneidensis MR-1 is a bacterium that utilizes a sigma-28 regulated transcriptional network to express coordinately regulated genes. A computer-based (in silico) analysis predicted that the sigma-28 regulatory network contained several genes necessary for flagellar motility. However, several additional genes, mostly annotated as encoding hypothetical proteins, were also linked to these motility genes. The purpose of this project is to analyze the products of transcriptional regulation of these genes using reverse transcriptase Polymerase Chain Reaction Assays. Then, the biological roles of the proteins will be assessed by constructing in-frame deletion mutants and screening these mutants for motility defects using chemotaxis assays and video-microscopy. Using these approaches it will be possible to evaluate the in silico method used to construct the sigma-28-regulated transcriptional network and potentially identify roles for a number of currently hypothetical proteins. This research will lay the foundations for a better understanding of the diversity of bacterial motility mechanisms (a topic about which very little is known), provide information on the role of bacterial motility in the biogeochemical cycling of metals (because MR-1 is a dissimilatory metal-reducing microbe), and facilitate modeling for bioremediation studies that involve microbial metal reduction. Broader impacts: The PI will enhance educational infrastructure by producing an open-access, web-based, series of lectures: Modules in Microbiology. Each module will encourage interdisciplinary thinking by emphasizing how different disciplines have impacted the field of microbiology. These modules will be advertised on the Society for Microbiology web sites of different countries and will provide an e-text for students and teachers unable to afford regular textbooks.