title: Responses to arsenate stress by Comamonas sp. strain CNB-1 at genetic and proteomic levels.
abstract: Comamonas sp. strain CNB-1, a chloronitrobenzene-degrading bacterium, was demonstrated to possess higher arsenate tolerance as compared with the mutant strain CNB-2. pCNB1, a plasmid harboured by CNB-1 but not CNB-2, contained the genetic cluster ars(RPBC)Com, which putatively encodes arsenate-resistance regulator, family II arsenate reductase, arsenite efflux pump and family I arsenate reductase, respectively, in Comamonas strain CNB-1. The arsC-negative Escherichia coli could gain arsenate resistance by transformation with arsPCom or arsCCom, indicating that these two genes might express functional forms of arsenate reductases. Intriguingly, when CNB-1 cells were exposed to arsenate, the transcription of arsPCom and arsCCom was measurable by RT-PCR, but only ArsPCom was detectable at protein level. To explore the proteins responding to arsenate stress, CNB-1 cells were cultured with and without arsenate and differential proteomics was carried out by two-dimensional PAGE (2-DE) and MALDI-TOF MS. A total of 31 differential 2-DE spots were defined upon image analysis and 23 proteins were identified to be responsive specifically to arsenate. Of these spots, 18 were unique proteins. These proteins were identified to be phosphate transporters, heat-shock proteins involved in protein refolding, and enzymes participating in carbon and energy metabolism.
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Ying-Fei
authors.initials: YF
authors.lastname: Ma
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Su-Wei
authors.initials: SW
authors.lastname: Qi
authors.affiliation: Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, China.
authors.forename: Bo
authors.initials: B
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Muhammad Tausif
authors.initials: MT
authors.lastname: Chaudhry
authors.affiliation: Beijing Genomics Institute, Chinese Academy of Sciences, Beijing 101300, China.
authors.forename: Si-Qi
authors.initials: SQ
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Microbial Resource, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Shuang-Jiang
authors.initials: SJ
authors.lastname: Liu
mesh_terms: D001149:Arsenates / Q000494:pharmacology*; D001426:Bacterial Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D020585:Comamonas / Q000187:drug effects* / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D019295:Computational Biology; D003470:Culture Media; D024881:Drug Resistance, Bacterial; D020869:Gene Expression Profiling; D015964:Gene Expression Regulation, Bacterial; D018869:Heat-Shock Response; D009154:Mutation; D020543:Proteome
chemical_list: D001149:Arsenates; D001426:Bacterial Proteins; D003470:Culture Media; D020543:Proteome; C025657:arsenic acid