| Microvesicles, also known as exosomes (EMVs) are nano-sized membrane particles secreted from nearly all cell types. Evidence has demonstrated that EMV have fundamental roles in multiple biological processes including immune response, tumor progression and heart repair. The various functions of EMV are determined by the cargo components. However, the cargo sorting mechanism is little understood. Glycosylation is the most common post-translational modification for mammalian cells. Early study from our lab indicates that EMVs released from a range of biological sources share a conserved glycomic profile that featured in high mannose, poly/multiantennary LacNAc, complex N-link glycan and alpha2-6 sialic acid, suggesting a potential role of glycans in EMV biogenesis and cargo recruitment. In my research, we further explore the role of N-glycans in the protein trafficking to vesicles. We identify EMV-enriched glycoproteins and demonstrate the alteration of their recruitment to EMVs as a function of their glycosylation status upon pharmacological manipulation. In addition, we validate that the level of a specific glycoprotein, EWI-2, in EMVs is dependent on the number of N-glycans attached on the protein using genetic manipulation. Furthermore, we investigate related galectins in EMV glycan-dependent trafficking and show a potential role of galectin-3 in EWI-2 recruitment to EMVs. Taken together, our data provide strong evidence that N-linked glycans are a sorting determinant for EMV cargo recruitment. |
