Characterization of ASNA-1 with Arsenic in Caenorhabditis elegans

• Main Authors: Jui-Tung Liu, 劉瑞桐
• Other Authors: Vivian Hsiu-Chuan Liao
• Format: Others
• Language: en_US
• Online Access: http://ndltd.ncl.edu.tw/handle/253dmn

碩士 === 國立臺灣大學 === 生物環境系統工程學研究所 === 97 === Arsenic is a known human carcinogen and a potent toxin. It is a major environmental pollutant. Nearly in every organism, from prokaryotes to eukaryotes, have mechanisms for arsenic detoxification. In Caenorhabditis elegans, the gene asna-1 has been identified as the homolog of ArsA in Escherichia coli (E. coli) and involved in arsenic detoxification. To identify genes interacting with asna-1, the candidate genes were identified by gene interaction predicted program. RNA interference (RNAi) analysis was performed to screen for asna-1 interacted gene in the presence of As(III) and we found the anion transporter ABTS-1. Toxicity tests showed that both asna-1 mutant and abts-1 mutant were hypersensitive to As(III), indicating that both asna-1 and abts-1 are required for As(III) detoxification. ASNA-1 developmental mRNA expression induced by As(III) in vivo and in vitro were examined by transgenic C. elegans and real-time RT-PCR analysis, respectively. The results showed that ASNA-1 mRNA expression varied in different developmental stages of worms and adulthood had higher expression level. In addition, ASNA-1 mRNA expression was induced by As(III). Life span assay showed overexpression of ASNA-1 protein did not affect the longevity of nematodes but the deletion of abts-1 extended the life span of C. elegans. In this study, our results showed that ASNA-1 was involved in As(III) resistance and ABTS-1 might act as the corresponding transporter to As(III) detoxification. ABTS-1 might be involved in insulin-like signaling (IIS) pathway because of the extension of life span in abts-1 mutant.