- Title
- Probing the interaction of tetraspanin CD151 with integrin α3β1 using a panel of monoclonal antibodies with distinct reactivities toward the CD151-integrin α3β1 complex
- Creator
- Yamada, Masashi; Tamura, Yumiko; Sanzen, Noriko; Sato-Nishiuchi, Ryoko; Hasegawa, Hitoshi; Ashman, Leonie K.; Rubinstein, Eric; Yanez-Mo, Maria; Sanchez-Madrid, Francisco; Sekiguchi, Kiyotoshi
- Relation
- Biochemical Journal Vol. 415, Issue 3, p. 417-427
- Publisher Link
- http://dx.doi.org/10.1042/bj20071625
- Publisher
- Portland Press
- Resource Type
- journal article
- Date
- 2008
- Description
- CD151, a member of the tetraspanin family of proteins, forms a stable complex with integrin α3β1 and regulates integrin-mediated cell-substrate adhesion. However, the molecular basis of the stable association of CD151 with integrin α3β1 remains poorly understood. In the present study, we show that a panel of anti-human CD151 mAbs (monoclonal antibodies) could be divided into three groups on the basis of their abilities to co-immunoprecipitate integrin α3: Group-1 mAbs were devoid of sufficient activities to co-precipitate integrin α3 under both low- and high-stringency detergent conditions; Group-2 mAbs co-precipitated integrin α3 under low-stringency conditions; and Group-3 mAbs exhibited strong co-precipitating activities under both conditions. Group-1 mAbs in particular exhibited increased reactivity toward integrin α3β1-unbound CD151, indicating that the binding sites for Group-1 mAbs are partly blocked by bound integrin α3β1. Epitope mapping using a series of CD151 mutants with substitutions at amino acid residues that are not conserved between human and mouse CD151 revealed that Gly¹⁷⁶/Gly¹⁷⁷, Leu¹⁹¹ and Gln¹⁹⁴ comprise epitopes characteristic of Group-1 mAbs. Replacement of short peptide segments, each containing one of these epitopes, with those of other tetraspanins lacking stable interactions with integrin α3β1 demonstrated that the segment from Cys¹⁸⁵ to Cys¹⁹², including Leu¹⁹¹, was involved in the stable association of CD151 with integrin α3β1, as was the Gln¹⁹⁴-containing QRD peptide. Taken together these results indicate that two consecutive segments including two Group-1 epitopes, Leu¹⁹¹ and Gln¹⁹⁴, comprise an interface between CD151 and integrin α3β1, and, along with the epitope including Gly¹⁷⁶/Gly¹⁷⁷, are concealed by bound integrin.
- Subject
- basement membrane; CD81; CD9; cell adhesion; integrin α3β1; laminin
- Identifier
- uon:5526
- Identifier
- http://hdl.handle.net/1959.13/43413
- Identifier
- ISSN:0264-6021
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