Phosphorylation of vascular endothelial cadherin controls lymphocyte emigration.
Lymphocytes emigrate from the circulation to target tissues through the microvascular endothelial cell (EC) barrier. During paracellular transmigration cell-cell junctions have been proposed to disengage and provide homophilic and heterophilic interaction surfaces in a zip-like process. However, it is not known whether ECs modulate junction proteins during this process. Here we show that tyrosine phosphorylation of adherens junction vascular endothelial cadherin (VEC) is required for successful transendothelial lymphocyte migration. We found that adhesion of lymphocytes or activation of the endothelial intercellular adhesion molecule 1 (ICAM1) led to tyrosine phosphorylation of VEC. Substitution of tyrosine for phenylalanine in VEC at positions 645, 731 or 733 produced ECs that were significantly less permissive to lymphocyte migration. We also found that these same tyrosine residues are involved in ICAM1-dependent changes of VEC phosphorylation. ICAM1 activation enhanced transendothelial permeability, suggesting the occurrence of junction disassembly. In agreement, the expression of VEC mutated at Y645F, Y731F or Y733F predominantly affected lymphocyte transmigration in paracellular areas. Taken together, these results demonstrate that phosphorylation of adherens junctions constitutes a molecular endpoint of lymphocyte-induced vascular EC signaling and may be exploited as a new target of anti-inflammatory therapies.
Turowski
Patric
P
Division of Cell Biology, Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 9EL, UK. p.turowski@ucl.ac.uk
Martinelli
Roberta
R
Crawford
Rebecca
R
Wateridge
David
D
Papageorgiou
Anna-Pia
AP
Lampugnani
Maria Grazia
MG
Gamp
Alexander C
AC
Vestweber
Dietmar
D
Adamson
Peter
P
Dejana
Elisabetta
E
Greenwood
John
J
D022005:Adherens Junctions / Q000502:physiology; D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D000818:Animals; D016466:CHO Cells; D015820:Cadherins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002460:Cell Line; D002465:Cell Movement; D017124:Conserved Sequence; D006224:Cricetinae; D003412:Cricetulus; D004730:Endothelium, Vascular / Q000378:metabolism*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D008214:Lymphocytes / Q000166:cytology*; D051379:Mice; D008969:Molecular Sequence Data; D016296:Mutagenesis; D010539:Permeability; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D020836:Protein Structure, Quaternary; D017434:Protein Structure, Tertiary; D000091363:Protocadherins; D051381:Rats; D016415:Sequence Alignment; D014443:Tyrosine / Q000378:metabolism
D015820:Cadherins; C090509:Icam1 protein, mouse; C528467:Pcdh12 protein, rat; D010750:Phosphoproteins; D000091363:Protocadherins; D018799:Intercellular Adhesion Molecule-1; D014443:Tyrosine