Growth-phase regulation of the proteome of Rhodobacter capsulatus.
EMSL Project ID
27392
Abstract
The alpha-proteobacterium Rhodobacter capsulatus uses a histidyl-aspartyl signaling system for growth-phase-dependent regulation of expression of some genes. The response regulator protein CtrA is the transcriptional regulator component of this signaling system, and is required for the growth-phase-dependent expression of genes responsible for genetic exchange and motility in R. capsulatus. The questions to be addressed by this proposed research are: 1) How does the R. capsulatus proteome change over the growth phase? and, 2) What is the role of the transcriptional regulator CtrA in these changes? The objectives of the proposed research are to develop an accurate mass and time (AMT) tag database for R. capsulatus, use this as a reference to allow comparison of protein expression patterns for wild-type and ctrA- strains of R. capsulatus, and to analyze the proteomic dynamics of R. capsulatus over the culture growth-phase. This proposed research fits within the EMSL mission by contributing to discovery in environmental molecular sciences. Specifically, this research fits within the "Biological Interactions and Dynamics" theme by addressing 1) temporal disposition of proteins in cells and, 2) regulatory mechanisms controlling the dynamics of protein composition in cells. We will first analyze the wild-type R. capsulatus proteomes associated with the early-log and "late"-stationary growth-phases, and then repeat this growth-phase comparison of samples with a ctrA- mutant strain of R. capsulatus. The AMT-tag approach will be applied for these proteomic analyses. The proteomic data generated through the experiments in this proposal provide an excellent complement to transcriptome experiments that will be done in parallel in the Lang laboratory at Memorial University. It is anticipated that this work will generate several outstanding publications and the availability of the combination of the proteomic and transcriptomic data will improve these publications significantly. This research provides the framework for future inter-species comparative analyses with other model bacteria such as Rhodobacter sphaeroides. Additionally, these proteomics experiments will benefit the genome sequence annotation for R. capsulatus.
Project Details
Project type
Exploratory Research
Start Date
2008-01-01
End Date
2009-01-04
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members
Related Publications
Mercer, R.G. Regulation and production of the Gene Transfer Agent (RcGTA) in Rhodobacter capsulatus. Poster presentation at Canadian Society of Microbiologists Conference; June 2010, Hamilton, Canada.
Mercer, R. G., S. J. Callister, M. S. Lipton, L. Pasa-Tolic, H. Strnad, V. Paces, J. T. Beatty, and A. S. Lang. 2010. Loss of the response regulator CtrA causes pleiotropic effects on gene expression but does not affect growth phase regulation in Rhodobacter capsulatus. Journal of Bacteriology 192: 2701-2710
Pena-Castillo L, R Mercer, A Gurinovich, SJ Callister, AT Wright, A Westbye, JT Beatty, and AS Lang. 2014. "Gene co-expression network analysis in Rhodobacter capsulatus and application to comparative expression analysis of Rhodobacter sphaeroides ." BMC Genomics 15(730):, doi:10.1186/1471-2164-15-730