Interaction of nectin with afadin is necessary for its clustering at cell-cell contact sites but not for its cis dimerization or trans interaction.
We have recently found a novel functional unit of cell-cell adhesion at cadherin-based adherens junctions, consisting of at least nectin, a homophilic cell adhesion molecule, and afadin, an actin filament-binding protein, which connects nectin to the actin cytoskeleton. Here we studied a mechanism of cell-cell adhesion of the nectin-afadin system by use of a cadherin-deficient L cell line stably expressing the intact form of mouse nectin-2alpha, a truncated form of nectin-2alpha incapable of interacting with afadin (nectin-2alpha-DeltaC), or a point-mutated form of nectin-2alpha capable of interacting with afadin and a cadherin-expressing EL cell line, which transiently expressed the point-mutated form of nectin-2alpha. We found that the interaction of nectin-2alpha with afadin was necessary for their clustering at cell-cell contact sites. However, nectin-2alpha-DeltaC showed cis dimerization and trans interaction, both of which did not require the interaction of nectin-2alpha with afadin. We have previously shown in EL cells that the interaction of nectin-1 with afadin is necessary for its recruitment to adherens junctions. We found that the trans interaction of nectin-2alpha was furthermore necessary for this recruitment. On the basis of these observations, we propose a model for the mechanism of cell-cell adhesion of nectin and roles of afadin in this mechanism.
Miyahara
M
M
Takai Biotimer Project, ERATO, Japan Science and Technology Corporation, c/o JCR Pharmaceuticals Co., Ltd., 2-2-10 Murotani, Nishi-ku, Kobe 651-2241, Japan.
Nakanishi
H
H
Takahashi
K
K
Satoh-Horikawa
K
K
Tachibana
K
K
Takai
Y
Y
D000818:Animals; D015820:Cadherins / Q000378:metabolism; D002448:Cell Adhesion / Q000502:physiology*; D015815:Cell Adhesion Molecules / Q000235:genetics / Q000378:metabolism*; D003432:Cross-Linking Reagents; D019281:Dimerization; D007365:Intercellular Junctions / Q000378:metabolism*; D016547:Kinesins; D051379:Mice; D008840:Microfilament Proteins / Q000378:metabolism*; D008961:Models, Structural; D009218:Myosins; D000075983:Nectins; D017354:Point Mutation; D011233:Precipitin Tests; D011485:Protein Binding
C490657:Afdn protein, mouse; D015820:Cadherins; D015815:Cell Adhesion Molecules; D003432:Cross-Linking Reagents; D008840:Microfilament Proteins; C000619015:Nectin1 protein, mouse; D000075983:Nectins; C108835:afadin; D009218:Myosins; D016547:Kinesins