Location, location, location: new insights into O-GalNAc protein glycosylation

Trends Cell Biol. 2011 Mar;21(3):149-58. doi: 10.1016/j.tcb.2010.11.004. Epub 2010 Dec 8.

Abstract

O-GalNAc glycosylation of proteins confers essential structural, protective and signaling roles in eumetazoans. Addition of O-glycans onto proteins is an extremely complex process that regulates both sites of attachment and the types of oligosaccharides added. Twenty distinct polypeptide GalNAc-transferases (GalNAc-Ts) initiate O-glycosylation and fine-tuning their expression provides a mechanism for regulating this action. Recently, a new mode of regulation has emerged where activation of Src kinase selectively redistributes Golgi-localized GalNAc-Ts to the ER. This relocalization results in a strong increase in the density of O-glycan decoration. In this review, we discuss how different mechanisms can regulate the number and the types of O-glycans decorating proteins. In addition, we speculate how Src-dependent relocation of GalNAc-Ts could play an important role in cancerous cellular transformation.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Glycoproteins / chemistry
  • Glycoproteins / metabolism*
  • Glycosylation
  • Humans
  • N-Acetylgalactosaminyltransferases / metabolism
  • Polysaccharides / metabolism
  • Protein Transport
  • Substrate Specificity

Substances

  • Glycoproteins
  • Polysaccharides
  • N-Acetylgalactosaminyltransferases
  • polypeptide N-acetylgalactosaminyltransferase