UDP-sugar substrates of HAS3 regulate its O-GlcNAcylation, intracellular traffic, extracellular shedding and correlate with melanoma progression
- Cell Mol Life Sci. 2016 Aug;73(16):3183-204. doi: 10.1007/s00018-016-2158-5.
- 1. Institute of Biomedicine, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland. [email protected].
- 2. Institute of Biomedicine, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland.
- 3. Faculty of Biochemistry and Molecular Medicine, University of Oulu, 90014, Oulu, Finland.
- 4. A. I. Virtanen Institute for Molecular Sciences, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland.
- 5. Institute of Biomedicine, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland. [email protected].
- 6. Institute of Dentistry, School of Medicine, University of Eastern Finland, 70210, Kuopio, Finland. [email protected].
Hyaluronan content is a powerful prognostic factor in many Cancer types, but the molecular basis of its synthesis in Cancer still remains unclear. Hyaluronan synthesis requires the transport of hyaluronan synthases (HAS1-3) from Golgi to plasma membrane (PM), where the Enzymes are activated. For the very first time, the present study demonstrated a rapid recycling of HAS3 between PM and endosomes, controlled by the cytosolic levels of the HAS substrates UDP-GlcUA and UDP-GlcNAc. Depletion of UDP-GlcNAc or UDP-GlcUA shifted the balance towards HAS3 endocytosis, and inhibition of hyaluronan synthesis. In contrast, UDP-GlcNAc surplus suppressed endocytosis and lysosomal decay of HAS3, favoring its retention in PM, stimulating hyaluronan synthesis, and HAS3 shedding in extracellular vesicles. The concentration of UDP-GlcNAc also controlled the level of O-GlcNAc modification of HAS3. Increasing O-GlcNAcylation reproduced the effects of UDP-GlcNAc surplus on HAS3 trafficking, while its suppression showed the opposite effects, indicating that O-GlcNAc signaling is associated to UDP-GlcNAc supply. Importantly, a similar correlation existed between the expression of GFAT1 (the rate limiting enzyme in UDP-GlcNAc synthesis) and hyaluronan content in early and deep human melanomas, suggesting the association of UDP-sugar metabolism in initiation of melanomagenesis. In general, changes in glucose metabolism, realized through UDP-sugar contents and O-GlcNAc signaling, are important in HAS3 trafficking, hyaluronan synthesis, and correlates with melanoma progression.