Bacterial cells have evolved multiple regulatory mechanisms to ensure that their subcellular structures and organelles, such as pili and flagella, are assembled and positioned correctly. Our goal is to determine how the core components of a conserved regulatory system, and their interactions, have been adapted to serve the particular needs of different organisms. In Caulobacter crescentus, the protein components of this regulatory system (PodJ, DivJ, and PleC) follow defined patterns of subcellular localization that contribute to asymmetric cell morphology: organelles specifically develop at one pole but not the other. The regulatory components are conserved in Sinorhizobium meliloti, a related bacterium that induces nodule formation in plant roots during symbiosis. However, S. meliloti cells are morphologically symmetric compared to C. crescentus. We will examine how these conserved components function in S. meliloti to regulate the assembly of surface organelles and how this regulation affects host-microbe interaction. (1) We will first determine the localization patterns of the regulatory proteins and the phenotypes of null mutants that lack the proteins. (2) We will then detect and analyze changes in the mutants'transcriptional profiles to see if the proteins control expression of similar genes in different species. (3) We will also assess whether the mutations disrupt interaction between the bacterium and its hosts, preventing effective nodulation. In addition to these research objectives, the principal investigator aims to achieve the following developmental objectives under the guidance of a senior scientist: (4) establish an independent research group, (5) enhance mentoring skills, and (6) improve the quality of research. Relevance to Public Health: The proposed research is expected to reveal the driving principles of a regulatory pathway that exists in multiple bacterial species, including pathogens. Components of the pathway may serve as targets for new antimicrobial compounds.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Pilot Research Project (SC2)
Project #
5SC2GM082318-03
Application #
7798997
Study Section
Special Emphasis Panel (ZGM1-MBRS-7 (SC))
Program Officer
Anderson, James J
Project Start
2008-06-01
Project End
2012-04-30
Budget Start
2010-05-01
Budget End
2012-04-30
Support Year
3
Fiscal Year
2010
Total Cost
$115,125
Indirect Cost
Name
San Francisco State University
Department
Biology
Type
Schools of Arts and Sciences
DUNS #
942514985
City
San Francisco
State
CA
Country
United States
Zip Code
94132
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Curtis, Patrick D; Quardokus, Ellen M; Lawler, Melanie L et al. (2012) The scaffolding and signalling functions of a localization factor impact polar development. Mol Microbiol 84:712-35
Zhang, Peng; Hernandez, Daniel; Cannan, Drake et al. (2012) Trapping and rotating microparticles and bacteria with moiré-based optical propelling beams. Biomed Opt Express 3:1891-7
Arellano, Benjamin H; Ortiz, Janett D; Manzano, Janet et al. (2010) Identification of a dehydrogenase required for lactose metabolism in Caulobacter crescentus. Appl Environ Microbiol 76:3004-14