ARS2(Arsenite resistance protein 2) confers arsenite resistance. The protein belongs to the ARS2 family. Arsenic is a human carcinogen whose mechanism of action is unknown. The arsenite acts as a comutagen by interfering with DNA repair. Two genes, ASR1(Arsenite resistance protein 1) and ASR2 (Arsenite resistance protein 2), confer arsenite resistance to arsenite-sensitive cells. ASR1 shows almost complete homology with the rat fau gene, a tumor suppressor gene which contains a ubiquitin like region fused to S30 ribosomal protein. Arsenite inhibits ubiquitin dependent proteolysis. The tumor suppressor fau gene product or some other aspect of the ubiquitin system may be a target for arsenic toxicity and that disruption of the ubiquitin system may contribute to the genotoxicity and carcinogenicity of arsenite.