Dynamic trafficking and turnover of JAM-C is essential for endothelial cell migration

PLoS Biol. 2019 Dec 2;17(12):e3000554. doi: 10.1371/journal.pbio.3000554. eCollection 2019 Dec.


Junctional complexes between endothelial cells form a dynamic barrier that hinders passive diffusion of blood constituents into interstitial tissues. Remodelling of junctions is an essential process during leukocyte trafficking, vascular permeability, and angiogenesis. However, for many junctional proteins, the mechanisms of junctional remodelling have yet to be determined. Here, we used receptor mutagenesis, horseradish peroxidase (HRP), and ascorbate peroxidase 2 (APEX-2) proximity labelling, alongside light and electron microscopy (EM), to map the intracellular trafficking routes of junctional adhesion molecule-C (JAM-C). We found that JAM-C cotraffics with receptors associated with changes in permeability such as vascular endothelial cadherin (VE-Cadherin) and neuropilin (NRP)-1 and 2, but not with junctional proteins associated with the transmigration of leukocytes. Dynamic JAM-C trafficking and degradation are necessary for junctional remodelling during cell migration and angiogenesis. By identifying new potential trafficking machinery, we show that a key point of regulation is the ubiquitylation of JAM-C by the E3 ligase Casitas B-lineage lymphoma (CBL), which controls the rate of trafficking versus lysosomal degradation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / metabolism
  • Antigens, CD / metabolism
  • Cadherins / metabolism
  • Capillary Permeability
  • Cell Adhesion
  • Cell Adhesion Molecules / metabolism*
  • Cell Adhesion Molecules / physiology
  • Cell Movement / physiology*
  • Endothelial Cells / physiology*
  • Endothelium, Vascular / metabolism
  • HEK293 Cells
  • Human Umbilical Vein Endothelial Cells
  • Humans
  • Intercellular Junctions / physiology
  • Junctional Adhesion Molecule C
  • Leukocytes / physiology
  • Neuropilins / metabolism
  • Protein Transport / physiology
  • Proto-Oncogene Proteins c-cbl / metabolism


  • Adaptor Proteins, Signal Transducing
  • Antigens, CD
  • Cadherins
  • Cell Adhesion Molecules
  • JAM3 protein, human
  • Junctional Adhesion Molecule C
  • Neuropilins
  • cadherin 5
  • CBLB protein, human
  • Proto-Oncogene Proteins c-cbl