Dual interaction of JAM-C with JAM-B and alpha(M)beta2 integrin: function in junctional complexes and leukocyte adhesion.

Journal article

The junctional adhesion molecules (JAMs) have been recently described as interendothelial junctional molecules and as integrin ligands. Here we show that JAM-B and JAM-C undergo heterophilic interaction in cell-cell contacts and that JAM-C is recruited and stabilized in junctional complexes by JAM-B. In addition, soluble JAM-B dissociates soluble JAM-C homodimers to form JAM-B/JAM-C heterodimers. This suggests that the affinity of JAM-C monomers to form dimers is higher for JAM-B than for JAM-C. Using antibodies against JAM-C, the formation of JAM-B/JAM-C heterodimers can be abolished. This liberates JAM-C from its vascular binding partner JAM-B and makes it available on the apical side of vessels for interaction with its leukocyte counter-receptor alpha(M)beta2 integrin. We demonstrate that the modulation of JAM-C localization in junctional complexes is a new regulatory mechanism for alpha(M)beta2-dependent adhesion of leukocytes.

Authors: Lamagna, C; Meda, P; Mandicourt, G; Brown, J; Gilbert, R

• Publication status: Published
• Journal: Molecular biology of the cell
• Volume: 16
• Issue: 10
• Pages: 4992-5003
• Publication date: 2005-10-01
• DOI: 10.1091/mbc.e05-04-0310
• EISSN: 1939-4586
• ISSN: 1059-1524
• Language: English
• Keywords: Green Fluorescent Proteins; Cricetulus; Microscopy, Immunoelectron; Recombinant Fusion Proteins; Leukocytes; Cricetinae; Macrophage-1 Antigen; Coculture Techniques; Intercellular Junctions; Cell Adhesion; Mice; Mice, Inbred C57BL; Cell Adhesion Molecules; Cell Line; Humans; Peptides; Endothelium; Animals; Immunoglobulins