| The extreme bacterium, Deinococcus radiodurans, can survive lethal doses of ionizing radiation. Efficient DNA repair mechanism, rapid DNA damage mechanisms and a variety of antioxidant contribute to the extreme radio-resistance of D. radiodurans.However, the mechanisms underlying its stress resistance properties are unclear at present.Protein acetylation is an important type of protein modification after translation.With the development of proteomics technology, we found that protein acetylation is widely existed in organisms. Advanced proteomics studies have greatly expanded our knowledge on the extent of protein N-lysine acetylation sites, which play crucial roles in several cellular processes, such as regulation and metabolism. Few studies to date have focused on the alteration of acetylation profiles in response to stress conditions, such as ionizing radiation.In the current thesis,the alteration of acetylation profiles in response to ionizing radiation in Deinococcus radiodurans was investigated.We initially found that the lysine acetylation pattern of the D. radiodurans proteome is significantly altered during post-irradiation recovery using Western blotting. To further reveal the acetylation alterations in response to radiation, acetylated peptides were enriched using anti-lysine-acetylation antibody from both unirradiated and irradiated cells, and analyzed with nano-LC/MS/MS. Consequently, we identified31acetylation sites of21proteins in unirradiated cells and19acetylation sites of14proteins in irradiated cells. The identified proteins appear to function in diverse pathways, including transcription, translation, stress response, and metabolism. Interestingly, the majority of acetylated proteins in unirradiated and irradiated cells were different. Our data collectively suggest that acetylation and deacetylation events occur following irradiation in D. radiodurans, and possibly play a role in the post-irradiation recovery process. |
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