A distinct PAR complex associates physically with VE-cadherin in vertebrate endothelial cells.
A cell polarity complex consisting of partitioning defective 3 (PAR-3), atypical protein kinase C (aPKC) and PAR-6 has a central role in the development of cell polarity in epithelial cells. In vertebrate epithelial cells, this complex localizes to tight junctions. Here, we provide evidence for the existence of a distinct PAR protein complex in endothelial cells. Both PAR-3 and PAR-6 associate directly with the adherens junction protein vascular endothelial cadherin (VE-cadherin). This association is direct and mediated through non-overlapping domains in VE-cadherin. PAR-3 and PAR-6 are recruited independently to cell-cell contacts. Surprisingly, the VE-cadherin-associated PAR protein complex lacks aPKC. Ectopic expression of VE-cadherin in epithelial cells affects tight junction formation. Our findings suggest that in endothelial cells, another PAR protein complex exists that localizes to adherens junctions and does not promote cellular polarization through aPKC activity. They also point to a direct role of a cadherin in the regulation of cell polarity in vertebrates.
Iden
Sandra
S
Institute of Medical Biochemistry, ZMBE, University of Münster, Von-Esmarch-Str. 56, D-48149 Münster, Germany.
Rehder
Daniela
D
August
Benjamin
B
Suzuki
Atsushi
A
Wolburg-Buchholz
Karen
K
Wolburg
Hartwig
H
Ohno
Shigeo
S
Behrens
Jürgen
J
Vestweber
Dietmar
D
Ebnet
Klaus
K
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D015703:Antigens, CD / Q000378:metabolism*; D016466:CHO Cells; D015820:Cadherins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D002450:Cell Communication; D018797:Cell Cycle Proteins / Q000378:metabolism*; D002460:Cell Line; D006224:Cricetinae; D004285:Dogs; D042783:Endothelial Cells / Q000378:metabolism*; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism; D019108:Tight Junctions / Q000378:metabolism / Q000473:pathology; D014162:Transfection; D000099152:Cadherin 5
D048868:Adaptor Proteins, Signal Transducing; D015703:Antigens, CD; D015820:Cadherins; D002352:Carrier Proteins; D018797:Cell Cycle Proteins; D008565:Membrane Proteins; D011493:Protein Kinase C; D000099152:Cadherin 5; C509689:PARD3 protein, human; C499657:PARD6A protein, human; C115015:PKC-3 protein