Cell membrane polyamine/proton antiporter, involved in the detoxification of excess polyamines in the cytoplasm. Recognizes spermidine, spermine and the antimalarial drug quinidine, but not quinine, chloroquine and mefloquine. By transcription factor HAA1 in response to acetaldehyde accumulation. Present with 21400 molecules/cell in log phase SD medium. Belongs to the major facilitator superfamily. DHA1 family. Polyamines/proton antiporter (TC 2.A.1.2.16) subfamily.