Identification of a conserved glycan signature for microvesicles

J Proteome Res. 2011 Oct 7;10(10):4624-33. doi: 10.1021/pr200434y. Epub 2011 Sep 23.

Abstract

Microvesicles (exosomes) are important mediators of intercellular communication, playing a role in immune regulation, cancer progression, and the spread of infectious agents. The biological functions of these small vesicles are dependent on their composition, which is regulated by mechanisms that are not well understood. Although numerous proteomic studies of these particles exist, little is known about their glycosylation. Carbohydrates are involved in protein trafficking and cellular recognition. Glycomic analysis may thus provide valuable insights into microvesicle biology. In this study, we analyzed glycosylation patterns of microvesicles derived from a variety of biological sources using lectin microarray technology. Comparison of the microvesicle glycomes with their parent cell membranes revealed both enrichment and depletion of specific glycan epitopes in these particles. These include enrichment in high mannose, polylactosamine, α-2,6 sialic acid, and complex N-linked glycans and exclusion of terminal blood group A and B antigens. The polylactosamine signature derives from distinct glycoprotein cohorts in microvesicles of different origins. Taken together, our data point to the emergence of microvesicles from a specific membrane microdomain, implying a role for glycosylation in microvesicle protein sorting.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Adult
  • Carbohydrates / chemistry
  • Cell Line, Tumor
  • Cell Membrane / metabolism
  • Exosomes / metabolism
  • Female
  • Gene Expression Regulation, Neoplastic
  • Glycomics
  • Glycoside Hydrolases / chemistry
  • Glycosylation
  • Humans
  • Jurkat Cells
  • Lectins / chemistry
  • Milk, Human / metabolism*
  • Oligonucleotide Array Sequence Analysis
  • Phosphorylation
  • Polysaccharides / chemistry*
  • Proteomics / methods*

Substances

  • Carbohydrates
  • Lectins
  • Polysaccharides
  • Glycoside Hydrolases