Options
Caenorhabditis elegans ArsA同源基因的調控與其功能之探討
Characterization of ArsA in Caenorhabditis elegans
Date Issued
2006
Date
2006
Author(s)
Tseng, Yuen-Yi
DOI
en-US
Abstract
Arsenic is a potent toxin and carcinogen. In prokaryotes, arsenic detoxification is accomplished by chromosomal and plasmid operon-encoded efflux systems. Two Caenorhabditis elegans genes, Ce-arsA-1 and Ce-arsA-2, that are homologous to the Escherichia coli (E. coli) arsA genes were identified and characterized in this study. The level of Ce-arsA-1 transcription was significantly affected by heat, metalloids and heavy metal exposure. When Ce-arsA-1 expression was inhibited using RNA interference (RNAi), lower resistance of arsenite and antimonite were observed. This suggests that Ce-ArsA-1 is required for arsenite and antimonite tolerance in C. elegans.
We expressed and purified Ce-ArsA-1 protein, a nematode homologue of arsA encoding the ATPase component of E. coli arsenite/antimonite transporter. Purified MBP-Ce-ArsA-1 fusion protein was biochemically characterized, and its properties were compared with those of E. coli ArsA. The MBP-Ce-ArsA-1 exhibited a basal level of ATPase activity in the absence of arsenite or antimonite. Antimonite induced a 4.8 fold stimulation of ATPase activity, which was related to an increase in Vmax; arsenite induced 2.2 fold stimulation of ATPase activity. The results indicate that Ce-ArsA-1 is a distinct arsenite and antimonite-stimulated ATPase belonging to the same superfamily of ATPases represented by the E. coli ArsA protein.
We expressed and purified Ce-ArsA-1 protein, a nematode homologue of arsA encoding the ATPase component of E. coli arsenite/antimonite transporter. Purified MBP-Ce-ArsA-1 fusion protein was biochemically characterized, and its properties were compared with those of E. coli ArsA. The MBP-Ce-ArsA-1 exhibited a basal level of ATPase activity in the absence of arsenite or antimonite. Antimonite induced a 4.8 fold stimulation of ATPase activity, which was related to an increase in Vmax; arsenite induced 2.2 fold stimulation of ATPase activity. The results indicate that Ce-ArsA-1 is a distinct arsenite and antimonite-stimulated ATPase belonging to the same superfamily of ATPases represented by the E. coli ArsA protein.
Subjects
砷
銻
Caenorhabditis elegans
Ce-ArsA
ATPase活性
Arsenite
Antimonite
ATPase activity
Type
thesis
File(s)
No Thumbnail Available
Name
ntu-95-R93622049-1.pdf
Size
23.53 KB
Format
Adobe PDF
Checksum
(MD5):e271eb63a7fa922bfa075844061e106b