FAQ: Which proteins are glycosylated?

Eukaryotic proteins in every cellular compartment have the potential to be glycosylated. Some nuclear and cytoplasmic proteins have O-GlcNAc. N- and O-glycans (O-GalNAc glycans) are generally present in secretory or membrane proteins. Proteoglycans of the extracellular matrix carry very large glycosaminoglycan chains (such as Heparin or Heparan Sulfate). Specific sub-sets of secretory proteins could have other glycan modifications as well. More information can be found in this article: Biosynthesis of Glycans in Eukaryotes