title: Zn-responsive proteome profiling and time-dependent expression of proteins regulated by MTF-1 in A549 cells.
abstract: Zinc plays a critical role in many biological processes. However, it is toxic at high concentrations and its homeostasis is strictly regulated by metal-responsive transcription factor 1 (MTF-1) together with many other proteins to protect cells against metal toxicity and oxidative stresses. In this paper, we used high-resolution two-dimensional gel electrophoresis (2DE) to profile global changes of the whole soluble proteome in human lung adenocarcinoma (A549) cells in response to exogenous zinc treatment for 24 h. Eighteen differentially expressed proteins were identified by MALDI TOF/TOF and MASCOT search. In addition, we used Western blotting and RT-PCR to examine the time-dependent changes in expression of proteins regulated by MTF-1 in response to Zn treatment, including the metal binding protein MT-1, the zinc efflux protein ZnT-1, and the zinc influx regulator ZIP-1. The results indicated that variations in their mRNA and protein levels were consistent with their functions in maintaining the homeostasis of zinc. However, the accumulation of ZIP-1 transcripts was down-regulated while the protein level was up-regulated during the same time period. This may be due to the complex regulatory mechanism of ZIP-1, which is involved in multiple signaling pathways. Maximal changes in protein abundance were observed at 10 h following Zn treatment, but only slight changes in protein or mRNA levels were observed at 24 h, which was the time-point frequently used for 2DE analyses. Therefore, further study of the time-dependent Zn-response of A549 cells would help to understand the dynamic nature of the cellular response to Zn stress. Our findings provide the basis for further study into zinc-regulated cellular signaling pathways.
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing, PR China.
authors.forename: Wen-jie
authors.initials: WJ
authors.lastname: Zhao
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing, PR China.
authors.forename: Qun
authors.initials: Q
authors.lastname: Song
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing, PR China.
authors.forename: Yan-hong
authors.initials: YH
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, PR China.
authors.forename: Ke-jin
authors.initials: KJ
authors.lastname: Li
authors.affiliation: MOE Key Laboratory of Modern Toxicology, School of Public Health, Nanjing Medical University, Nanjing, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Mao
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing, PR China.
authors.forename: Xin
authors.initials: X
authors.lastname: Hu
authors.affiliation: State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry & Chemical Engineering and Center of Materials Analysis, Nanjing University, Nanjing, PR China.
authors.forename: Hong-zhen
authors.initials: HZ
authors.lastname: Lian
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, PR China.
authors.forename: Wei-juan
authors.initials: WJ
authors.lastname: Zheng
authors.affiliation: State Key Laboratory of Pharmaceutical Biotechnology, School of Life Science, Nanjing University, Nanjing, PR China.
authors.forename: Zi-chun
authors.initials: ZC
authors.lastname: Hua
mesh_terms: D027682:Cation Transport Proteins / Q000235:genetics / Q000378:metabolism; D045744:Cell Line, Tumor; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D004847:Epithelial Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D006706:Homeostasis / Q000235:genetics; D006801:Humans; D008668:Metallothionein / Q000235:genetics / Q000378:metabolism; D020543:Proteome / Q000235:genetics* / Q000378:metabolism; D011650:Pulmonary Alveoli / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics* / Q000378:metabolism; D015398:Signal Transduction; D013312:Stress, Physiological; D013997:Time Factors; D014157:Transcription Factors / Q000235:genetics* / Q000378:metabolism; D019287:Zinc Sulfate / Q000494:pharmacology*; D000097809:Transcription Factor MTF-1
chemical_list: D027682:Cation Transport Proteins; D004268:DNA-Binding Proteins; D008668:Metallothionein; D020543:Proteome; D012333:RNA, Messenger; D014157:Transcription Factors; D019287:Zinc Sulfate; D000097809:Transcription Factor MTF-1; C498299:SLC30A1 protein, human; C403517:SLC39A1 protein, human; C407523:metallothionein isoform 1