ATPase Class I Type 8A2 (ATP8A2)

P-type ATPases, which are phosphorylated in their intermediate state, drive uphill transport of ions across membranes. Several subfamilies of P-type ATPases have been identified. One subfamily transports heavy metal ions, such as Cu(2+) or Cd(2+). Another subfamily transports non-heavy metal ions, such as H(+), Na(+), K(+), or Ca(+). A third subfamily transports amphipaths, such as phosphatidylserine. ATP8A2 contains 617 amino acids. Northern blot and RT-PCR analyses revealed ATP8A2 expression in brain and placenta but not in other tissues or tumor cell lines. Transfection of antisense, but not sense, constructs to ATP8A2 into a nontumorigenic cell line rendered the cells tumorigenic in nude mice. In situ RT-PCR hybridization analysis demonstrated expression of ATP8A2 in normal tissue and depressed expression in tumor tissue.