Cell membrane polyamine/proton antiporter, involved in the detoxification of excess polyamines in the cytoplasm. Recognizes spermine, but not spermidine. By transcription factor HAA1 in response to acetaldehyde accumulation. Present with 2760 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.