Role of interaction with vinculin in recruitment of vinexins to focal adhesions.
Although vinexin was originally identified as a protein binding to the proline-rich hinge region of vinculin, the functions and biochemical properties of the vinexin-vinculin interaction are not known. Here, we determined the affinity of the vinexin-vinculin interaction using surface plasmon resonance measurements and found that vinexin beta interacts with the C-terminal half of vinculin, which mimics an activated "open" form, with a threefold higher affinity than with the full-length "closed" vinculin. Coimmunoprecipitation experiments showed that cell adhesion on fibronectin enhances the vinexin-vinculin interaction. We also show that the interaction with vinculin is necessary for the efficient localization of vinexin alpha and beta at focal adhesions. These observations suggest a model that "activated" vinculin localized at focal adhesions recruits vinexins to focal adhesions.
Takahashi
Honami
H
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Sakyo-ku, Kyoto 606-8502, Japan.
Mitsushima
Masaru
M
Okada
Naoya
N
Ito
Takuya
T
Aizawa
Sanae
S
Akahane
Rie
R
Umemoto
Tsutomu
T
Ueda
Kazumitsu
K
Kioka
Noriyuki
N
D000818:Animals; D005353:Fibronectins / Q000378:metabolism; D022001:Focal Adhesions; D049452:Green Fluorescent Proteins / Q000378:metabolism; D051379:Mice; D009124:Muscle Proteins / Q000378:metabolism*; D041681:NIH 3T3 Cells; D011485:Protein Binding; D020349:Surface Plasmon Resonance; D016596:Vinculin / Q000378:metabolism*; D048868:Adaptor Proteins, Signal Transducing
D005353:Fibronectins; D049452:Green Fluorescent Proteins; D009124:Muscle Proteins; D016596:Vinculin; C117452:Sorbs3 protein, mouse; D048868:Adaptor Proteins, Signal Transducing