Glycosyltransferase required for the biosynthesis of heparan-sulfate and responsible for the alternating addition of beta-1-4-linked glucuronic acid (GlcA) and alpha-1-4-linked N-acetylglucosamine (GlcNAc) units to nascent heparan sulfate chains. Plays a central role in diffusion of morphogens hedgehog (hh), wingless (wg) and Decapentaplegic (dpp) via its role in heparan sulfate proteoglycans (HSPGs) biosynthesis, HSPGs being required for movement of Hh, Dpp and wg morphogens. 3-O-(beta-D-GlcA-(1->3)-beta-D-Gal-(1->3)-beta-D-Gal-(1->4)-beta-D-Xyl)-L-seryl-[protein] + UDP-N-acetyl-alpha-D-glucosamine = 3-O-(alpha-D-GlcNAc-(1->4)-beta-D-GlcA-(1->3)-beta-D-Gal-(1->3)-beta-D-Gal-(1->4)-beta-D-Xyl)-L-seryl-[protein] + H(+) + UDP Glycan metabolism; heparan sulfate biosynthesis. Interacts with sau. Localization to the Golgi may be regulated by sau (PubMed:23720043). In wing imaginal disk, it is ubiquitously expressed. Expressed throughout the developmental stages in both head and body from males and females. Belongs to the glycosyltransferase 47 family.