Glycosyltransferases that transfer GlcNAc and Gal to βGal residues with α1,4-linkages on glycoprotein and glycolipid templates, respectively, are categorized as α1,4-linkage glycosyltransferases. At present, two enzymes, namely, α1,4-N-acetylglucosaminyltransferase (α4GnT) and α1,4-galactosyltransferase (α4GalT, Gb3/CD77 synthase) are assigned to this family. α4GnT is responsible for biosynthesis of GlcNAcα1 → 4Galβ → R attached to O-glycans, whereas α4GalT is a key enzyme in the formation of Gb3/CD77 (Fig. 1). Since cDNAs encoding both enzymes were cloned by expression cloning by the authors (Nakayama et al. 1999; Kojima et al. 2000), we describe here the procedure for expression cloning of α1,4-linkage glycosyltransferases, focusing primarily on α4GnT.
KeywordsExpression Cloning Megakaryoblastic Leukemia Gland Mucous Cell Sibling Selection Infected Mouse Cell
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