Tuesday, May 1, 2012
Napoleon Ballroom C-D, 3rd fl (Sheraton New Orleans)
The ability of microorganisms to adapt to changes in the environment by modifying gene expression levels in response to various stimuli, is conferred by two-component signal transduction systems. According to the published genome annotation data, Deinococcus radiodurans has 19 putative sensory histidine kinases and 26 putative response regulator. However, little experimental report concerning about their function was published until now. D. radiodurans shows extraordinary tolerance to DNA damage. The sensor histidine kinase (DR_2419) and bacteriophytochrome two-component regulatory system (DR_BphPR) were sensitive in response to r-radiation. Deletion mutants (ΔDR_2419::Kmr and ΔbphPR::Kmr) showed higher sensitivity to r-radiation, hydrogen peroxide and mitomycin as compared to wild type. In this study, we compared transcriptome profiles of ΔDR_2419::Kmr and ΔbphPR::Kmr with those from wild type cell after 10 kGy r -radiation. The expression level of 72 genes and 28 genes were changed (>2-fold) ΔDR_2419::Kmr and ΔbphPR::Kmr, respectively. The ΔDR_2419::Kmr up-regulated genes responsible for biosynthesis protein, CobD (DR_B0010), DNA mismatch repair protein, MutS (DR_1976), amino acid ABC transporter and amino acid-binding protein, LivK (DR_A0263). The ΔbphPR::Kmr up-regulated genes responsible for cold shock protein, PprM (DR_0907), thymidine kinase, Tdk (DR_1984), B-cell receptor associated protein-related protein (DR_0482) and urea/short-chain amide ABC transporter, FmdE (DR_A0321). These results suggested that DR_2419, bphP and bphR genes are the two-component system control the gene expression in various functions and play an important role in radiation resistance of D. radiodurans.