[Isoform 1]: Choline/H+ antiporter, mainly in mitochodria (PubMed:10677542, PubMed:20665236, PubMed:23651124, PubMed:33789160). Also acts as a low-affinity ethanolamine/H+ antiporter, regulating the supply of extracellular ethanolamine (Etn) for the CDP-Etn pathway, redistribute intracellular Etn and balance the CDP-Cho and CDP-Etn arms of the Kennedy pathway (PubMed:33789160). ; [Isoform 3]: Does not exhibit choline transporter activity.
