Transports uridine diphosphate galactose (UDP-galactose) from the cytosol into the Golgi apparatus, functioning as an antiporter that exchanges UDP-galactose for UMP (PubMed:12682060, PubMed:9010752). It is also able to exchange UDP-galactose for AMP and CMP, and to transport UDP-N-acetylgalactosamine (UDP-GalNAc) and other nucleotide sugars (PubMed:11784306, PubMed:12682060). As a provider of UDP-galactose to galactosyltransferases present in the Golgi apparatus, it is necessary for globotriaosylceramide/globoside (Gb3Cer) synthesis from lactosylceramide (PubMed:30817854).