The first propeller domain of LRP6 regulates sensitivity to DKK1
| Autor: | Nenad Tomasevic, Victoria E. Ahn, Minke E. Binnerts, Jason Williams, William I. Weis, Kyung Ah Kim, Shirlee Yonkovich, Wouter Korver, Jessica M. Bright, Mei Zhou, John Leung, Shouchun Liu, Melissa Dixon, Delphine Gros, Xiaoming Zhan, Arie Abo |
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| Rok vydání: | 2009 |
| Předmět: |
musculoskeletal diseases
media_common.quotation_subject Blotting Western Plasma protein binding Biology Cell Line Wnt3 Protein Wnt3A Protein Humans Binding site Internalization Molecular Biology LDL-Receptor Related Proteins media_common Binding Sites Wnt signaling pathway LRP6 Antibodies Monoclonal Cell Biology Articles Flow Cytometry Endocytosis Cell biology Wnt Proteins DKK1 Biochemistry Low Density Lipoprotein Receptor-Related Protein-6 Mutation Intercellular Signaling Peptides and Proteins RNA Interference Signal transduction Protein Binding Signal Transduction |
| Zdroj: | Molecular biology of the cell. 20(15) |
| ISSN: | 1939-4586 |
| Popis: | The Wnt coreceptor LRP6 is required for canonical Wnt signaling. To understand the molecular regulation of LRP6 function, we generated a series of monoclonal antibodies against the extra cellular domain (ECD) of LRP6 and selected a high-affinity mAb (mAb135) that recognizes cell surface expression of endogenous LRP6. mAb135 enhanced Wnt dependent TCF reporter activation and antagonized DKK1 dependent inhibition of Wnt3A signaling, suggesting a role in modulation of LRP6 function. Detailed analysis of LRP6 domain mutants identified Ser 243 in the first propeller domain of LRP6 as a critical residue for mAb135 binding, implicating this domain in regulating the sensitivity of LRP6 to DKK1. In agreement with this notion, mAb135 directly disrupted the interaction of DKK1 with recombinant ECD LRP6 and a truncated form of the LRP6 ECD containing only repeats 1 and 2. Finally, we found that mAb135 completely protected LRP6 from DKK1 dependent internalization. Together, these results identify the first propeller domain as a novel regulatory domain for DKK1 binding to LRP6 and show that mAb against the first propeller domain of LRP6 can be used to modulate this interaction. |
| Databáze: | OpenAIRE |
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