Acts as a transporter of both UDP-galactose and UDP-N-acetylglucosamine into the Golgi lumen. Expressed exclusively in pharyngeal cells g1 and g2, lateral seam cells, spermatheca and vas deferens. In seam cells, expression is first detected in late embryos, persists to the fourth larval stage and disappears in adults. In glandular cells g1 and g2, expression begins in the first larval stage and remains visible until adulthood. Worms display altered surface antigenicity which prevents bacterial adherence. This is due to a deficiency in both O- and N-linked glycans. Belongs to the nucleotide-sugar transporter family. SLC35A subfamily.