ArsA protein is the catalytic component of an Escherichia coli plasmid R773-encoded ArsAB pump. In E.coli, the ArsAB pump provides resistance to arsenite and antimonite. At present, comparison with the data banks shows that there are sequences homologous to the bacterial arsA gene in Caenorhabditis elegans, Homo sapiens, Mus Musculus and Saccharomyces cerevisiae genome. The ArsA is proved to be associated with arsenical resistance in E.coli, but the function of ArsA homologous protein in other organisms is still unclear.
Initial studies show that deletion of ArsA homology protein in S.cerevisiae (yArsA protein) has no effect on utilization of different carbon sources, it means that yArsA protein is not directly related to carbon metabolism in aerobic or anaerobic condition. Also, it is probably not directly related to the arsenical resistance mechanism either. Knock-out strain has shown sensitivity to 5 mM Zn+2 when grown at 30℃ and 37℃. Therefore, yArsA protein may be involved in the general detoxification mechanism. Interestingly, the knock-out strain shows thermosensitivity at 40℃, it suggests that the yArsA protein may play a protective role at heat-stress condition. DNA multiploidy was detected in knock-out strain when grown at 40℃, this result suggested that yArsA protein defect may inhibit cytokinesis but not DNA replication when under heat-stress. The subcellular localization of yArsA and GFP fusion protein was determined by confocal microscope of intact cells. In cells expressing the recombinant protein, the fusion protein was found to display specific “punctate” structure, suggesting that the yArsA protein in S.cerevisiae is probably related to function in transport between the prevacuolar compartment and the vacuole or in the signal transduction.