The protein encoded by this gene is found in the membrane of the Golgi apparatus, where it transports nucleotide sugars into the Golgi. One such nucleotide sugar is CMP-sialic acid, which is imported into the Golgi by the encoded protein and subsequently glycosylated. Defects in this gene are a cause of congenital disorder of glycosylation type 2F (CDG2F). Two transcript variants encoding different isoforms have been found for this gene.[provided by RefSeq, Dec 2009].