ArsA Arsenite Transporter, ATP Binding Homolog 1 (ASNA1)

ASNA1 is the human homolog of the bacterial arsA gene. The human ARSA1 cDNA was isolated from a human ovarian carcinoma library and found to encode a 332-amino acid polypeptide having an N-terminal ATP-binding cassette (ABC) domain and a C-terminal domain of unknown function. The protein sequence is highly homologous throughout both domains to hypothetical arsA proteins of C. elegans and yeast. Northern blot analysis revealed that the ARSA1 gene is ubiquitously expressed. Southern blot analysis indicated the existence of 2 closely related ARSA genes in the human genome. The existence of a second human ARSA protein was further supported by Western blot analysis, which demonstrated that anti-ARSA1 antibodies identify 2 proteins of 37 and 42 kD.