%0 Journal Article
%T Transcriptome and proteome analyses of adaptive responses to methyl methanesulfonate in Escherichia coli K-12 and ada mutant strains
%A Jong Hwan Baek
%A Mee-Jung Han
%A Sang Yup Lee
%A Jong-Shin Yoo
%J BMC Microbiology
%D 2009
%I BioMed Central
%R 10.1186/1471-2180-9-186
%X Transcriptome profiling showed that 1138 and 2177 genes were differentially expressed in response to MMS treatment in the wild-type and mutant strains, respectively. A total of 81 protein spots representing 76 nonredundant proteins differentially expressed were identified using 2-DE and LC-MS/MS. In the wild-type strain, many genes were differentially expressed upon long-exposure to MMS, due to both adaptive responses and stationary phase responses. In the ada mutant strain, the genes involved in DNA replication, recombination, modification and repair were up-regulated 0.5 h after MMS treatment, indicating its connection to the SOS and other DNA repair systems. Interestingly, expression of the genes involved in flagellar biosynthesis, chemotaxis, and two-component regulatory systems related to drug or antibiotic resistance, was found to be controlled by Ada.These results show in detail the regulatory components and pathways controlling adaptive response and how the related genes including the Ada regulon are expressed with this response.Alkylation damage to DNA occurs when cells encounter alkylating agents in the environment or when active alkylators are generated by nitrosation of amino acids in metabolic pathways [1,2]. The DNA damage by alkylating agents results in disruption of DNA function and cell death. The alkylating agents represent an abundant class of chemical DNA damaging agent in our environment and are toxic, mutagenic, teratogenic and carcinogenic. Since we are continuously exposed to alkylating agents, and since certain alkylating agents are used for cancer chemotherapy, it is important to understand exactly how cells respond to these agents. Alkylating agents are commonly used anti-cancer drugs and remain important for the treatment of several types of cancer [3,4]. Alkylating drugs are mostly methylating agents (e.g. temozolomide and streptozotocin, an antibiotic) or chloroethylating agents (e.g. carmustine, lomustine and fotemustine) [5]. The effi
%U http://www.biomedcentral.com/1471-2180/9/186