Dr. Tim Comar, Professor, Mathematics:
Dr. David Rubush, Assistant Professor, Chemistry:
Rgg proteins contain an N-terminal DNA binding domain and a C-terminal peptide binding domain. The pheromones that interact with this domain are generally small hydrophobic peptides (termed SHP). Interaction leads to upregulation of target genes. Rgg QS pathways have been shown to regulate competence, biofilm formation, toxin production, and virulence in Gram-positive bacteria. We are interested in Rgg loci present in the probiotic and human commensal Lactobacillus acidophilus ATCC 4357.
L. acidophilus ATCC 4357 contains three predicted Rgg proteins named herein as Rgg499, Rgg1765, and Rgg155. No pheromones have been listed for Lactobacillus species. rgg499 is in a predicted six gene operon which includes a second transcriptional regulator and it is found upstream of maltose transport genes. rgg155 is in a predicted five gene operon and all genes are of unknown function. However, rgg155 was found to have some sensitivity under stress conditions in L. acidophilus NCFM. Lastly, rgg1765 is surrounded by predicted drug transporters and cell envelope proteases. Our main research questions are: What are the QS pathways regulated by Rgg proteins in L. acidophilus ATCC 4357 and what are the signals that induce these Rgg pathways?
Previous studies have shown Rgg positively or negatively regulate adjacent genes including itself. Most Rgg proteins are stand-alone and have been shown to be positive regulators. One negative regulator has been shown to be paired with positive regulators. Given the arrangement present in L. acidophilus, we hypothesize all Rgg(s) may be positive regulators. We have constructed luciferase transcriptional reporters to observe changes in transcription. In addition, our reporters will be used to perform phenotypic arrays to identify potential inducing environmental signals. These constructs will be expressed in L. acidophilus and a heterologous host. Results from this project will provide insight in Rgg regulation.
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Students at Benedictine University are offered the opportunity to conduct a state-of-art research by using equipment and methodologies similar to that used in modern R&D laboratories across the industry, such as potentiostats/galvanostats and solar simulators. Their research activities will meet the following objectives: analyzing the benefits from the renewable energy technologies, understanding the fundamental scientific principles behind them, learning and applying theoretical knowledge in real-time applications, hands-on measurements by using state-of-art equipment, and preparing students to enter the job market as skilled professionals or enroll in graduate schools with an advanced knowledge and experience in designing and conducting experiments.