Catalyzes the addition of GlcNAc or GlcUA monosaccharides to the nascent hyaluronan polymer. Therefore, it is essential to hyaluronan synthesis a major component of most extracellular matrices that has a structural role in tissues architectures and regulates cell adhesion, migration and differentiation. This is one of three isoenzymes responsible for cellular hyaluronan synthesis.
Subcellular locations: Cell membrane, Golgi apparatus membrane, Golgi apparatus, Trans-Golgi network membrane, Early endosome
Travels from endoplasmic reticulum (ER), Golgi to plasma membrane . Actives only when present in plasma membrane (By similarity). O-GlcNAcylation controls its membrane localization . A rapid recycling of HAS3 between plasma membrane and endosomes is controlled by the cytosolic levels of UDP-GlcUA and UDP-GlcNAc .