The Leucine-Responsive Protein in P. aeruginosa

A leucine responsive protein (Lrp) has been demonstrated to play a role as a global regulator of cellular metabolism in response to leucine in the intestinal bacterium Escherichia coli.   In E. coli, Lrp binds DNA to activate or repress the gene expression for up to thirty operons and has likely evolved to suit its particular biological niche.  Some genes involved include amino acid biosynthesis and the adherence fimbriae structure.  This proposal speculates about the possible role of Lrp as a global regulator in another bacterium, Pseudomonas aeruginosaP. aeruginosa is found ubiquitously and harmlessly throughout the environment but can be an important opportunistic, human pathogen.  The most important aspect of P. aeruginosa disease is, once an internal infection is in place within its human host, there is no known cure or effective therapy.  Pseudomonas is protected by two membranes surrounded by an extremely thick, mucoid structure, which helps it to be resistant to virtually all known antibiotic therapies and disinfectants.  It also produces adherence fimbriae (pili), which are critical for the initial infection.  Based on the E. coli profile, study of the Lrp protein may allow us to identify an important factor in the regulation of genes involved in cellular metabolism and possibly pathogenesis in P. aeruginosa.  Specifically, our lab seeks to determine the number and diversity of genes acted upon by Lrp to determine if Lrp is a global or local regulator of gene function in P. aeruginosa.



  • Griffin Lab Members 

    Mareena M. Pitts (MSIB graduate student)

    Matthew Taylor

    Ashley Hicks

    Rick Liebold

    Sean Fletcher

  • Publications
    Ila B. Lansky, Gudrun S. Lukat-Rodgers, Darci Block, Kenton R. Rodgers, Melanie Ratliff, and Angela Wilks. 2006. The cytoplasmic heme-binding protein (PhuS) from the heme uptake system of Pseudomonas aeruginosa is an intracellular heme-trafficking protein to the regioselective heme oxygenase. J. Biol. Chem. 9:13652-62

    Ratliff-Griffin, M., Wilks, A., Stojiljkovic, I. 2004. Bacterial Heme Oxygenases. Iron Transport in Bacteria. Book, In press.

    Perkins-Balding, D., Griffin-Ratliff, M., and Stojiljkovic, I. 2004. Iron Transport Systems inNeisseria meningitidis. Micro. Mol. Biol. Rev. 68 (1): 154-171.

    Ratliff, M., Zhu., W., Deshmukh, R., Wilks, A., and Stojiljkovic, I. 2001. Homologues ofNeisserial heme oxygenase in Gram-negative bacteria: degradation of heme by the product of the pigA gene of Pseudomonas aeruginosa. J. Bacteriol. 183 (21): 6394-6403.