Sergey Y. Vakhrushev, Ph.D. International Hupo 2016 Site-specific O-glycosylation is emerging as an important concept for regulating pro-tein processing and functions. However, full understanding of the nature and functions of this abundant type of protein glycosylation is severely hampered by lack of tools for prote-ome-wide characterization of O-glycan structures at specific sites in O-glycoproteins. The challenge of high throughput O-glycoproteomics has been partly met by recent advances in tagging strategies, genetic engineering of cells, and ETD based mass spectrometry (1). Advances in analysis of O-glycoproteins have been made and proteome-wide analysis of O-glycosylation sites is becoming available (2). The O-GalNAc glycoproteome is orchestrated by a large polypeptide GalNAc-T iso-enzyme family, and the roles of these each isoforms are poorly understood. Most of our current knowledge of these isoenzymes is based on in vitro enzyme assays with short peptide substrates. We have now expanded on this strategy and applied a quantitative ap-proach to show non-redundant O-glycosylation performed by a single polypeptide GalNAc-T using differential analysis of O-glycoproteomes produced in an isogenic cell model with and without knock-out or knock-in of GALNTs (3). Here we discuss different aspects of quantitative O-glycoproteomics applied to the analysis of human cell lines, body fluids and tissues.
https://youtu.be/fW8_i6A8RHA Center for Glycomics, Departments of Cellular and Molecular Medicine and School of Dentistry, Faculty of Health Sciences, University of Copenhagen, Blegdamsvej 3, DK-2200 Copenhagen N, Denmark.