B4galt1 - UDP-Gal:betaGlcNAc beta 1,4- galactosyltransferase, polypeptide 1

This gene encodes two distinct enzyme isoforms, a long membrane-bound form and a short soluble form. These alternate isoforms are thought to be produced through alternative nested transcription initiation and different in-frame start codon usage. These enzymes catalyze the transfer of galactose to acceptor sugars, such as N-acetylglucosamine and glucose. The long form of this enzyme is localized to the trans-Golgi membrane and is involved in glycoconjugate biosynthesis. The short form functions in lactose biosynthesis though formation of a heterodimer with alpha-lactalbumin. [provided by RefSeq, Nov 2012]