The yeast peroxisomal adenine nucleotide transporter: characterization of two transport modes and involvement in ΔpH formation across peroxisomal membranes

The yeast peroxisomal adenine nucleotide carrier, Ant1p, was shown to catalyse unidirectional transport in addition to exchange of substrates. In both transport modes, proton movement occurs. Nucleotide hetero-exchange is H+-compensated and electroneutral. Furthermore, microscopic fluorescence imaging of a pH-sensitive green fluorescent protein targeted to peroxisomes shows that Ant1p is involved in the formation of a ΔpH across the peroxisomal membrane, acidic inside.