Identification of the Region of α-Catenin That Plays an Essential Role in Cadherin-mediated Cell Adhesion*
- From the Department of Biochemistry, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan
Abstract
α-Catenin is an intrinsic component of the cadherin adhesion complex and is a 102-kDa protein with multiple interaction sites, including homodimerization sites, and binding sites for β- and γ-catenin (plakoglobin), α-actinin, and actin. Besides the binding to β- or γ-catenin, it is unknown, however, which interaction is critical for the function of cadherins. By expressing a series of E-cadherin-α-catenin chimeric molecules on leukemia cells (K562), we have identified the region of α-catenin that confers aggregation inducing activity to nonfunctional tail-less E-cadherin. The region has been mapped to the carboxyl-terminal 295 amino acids of α-catenin. Consistent with this result, expression in α-catenin-deficient cells (DLD-1/Δα) of a mutant α-catenin molecule consisting of the amino-terminal β-/γ-catenin-binding site and the carboxyl-terminal cell adhesion region identified in the above experiments induced E-cadherin-mediated cell aggregation and compaction. Cells expressing E-cadherin chimeric molecules with the homologous carboxyl-terminal region of vinculin, which contains the actin-binding site of vinculin, did not, however, aggregate as strongly as ones expressing E-cadherin-α-catenin chimeric molecules.
Footnotes
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↵* This work was supported by grants from the Ministry of Education, Science and Culture of Japan, the Naito Foundation for the Promotion of Science, and the Kodama Memorial Foundation.The costs of publication of this article were defrayed in part by the payment of page charges. The article must therefore be hereby marked “advertisement” in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.
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↵‡ To whom correspondence should be addressed: Dept. of Biochemistry, Faculty of Medicine, Kagoshima University, Kagoshima 890-8520, Japan. Tel.: 81-99-275-5246; Fax: 81-99-264-5618; E-mail:mozawa{at}med2.kufm.kagoshima-u.ac.jp.
- Abbreviations:
- EαMC
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E-cadherin-α-catenin chimeric protein
- EK cells
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K562 cells expressing E-cadherin.
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- Received March 23, 1998.
- Revision received July 10, 1998.
- The American Society for Biochemistry and Molecular Biology, Inc.
