RecX is Involved In the Switch between DNA Damage Response and Normal Metabolism in D. radiodurans

• DOI: 10.1093/jb/mvp072
• Publication Date: 2009-05-14T21:54:26Z
• Authors: D. Sheng; J. Jao; M. Li; P. Xu; J. Zhang
• Keywords: Proteomics; 0301 basic medicine; 0303 health sciences; DNA Repair; Reverse Transcriptase Polymerase Chain Reaction; Down-Regulation; Gene Expression Regulation, Bacterial; Up-Regulation; 3. Good health; DNA-Binding Proteins; Rec A Recombinases; 03 medical and health sciences; DNA Repair Enzymes; Bacterial Proteins; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization; Electrophoresis, Gel, Two-Dimensional; Deinococcus; Isoelectric Focusing; DNA Damage

Apart from inhibiting RecA activity through protein-protein interactions, Deinococcus radiodurans RecX inhibits the expression of RecA and two other anti-oxidant proteins. To identify the repertoire of proteins regulated by RecX, comparative proteomic studies were undertaken on a wild-type strain (R1) and recX null mutant (RecX(-)). Two-dimensional electrophoresis followed by MALDI-TOF identification revealed 35 differentially expressed proteins, including 12 up-regulated and 23 down-regulated proteins in the mutant. The 12 up-regulated proteins are DNA repair proteins, stress response proteins, and metabolism-related proteins. Most of these have been previously characterized as ionizing radiation-induced proteins. The 23 down-regulated proteins are mainly involved in cellular metabolism, and some of these are key enzymes in the metabolic pathway. Thus, RecX is suggested to be involved in the switch between DNA damage response and normal metabolism in D. radiodurans.