Eph receptor tyrosine kinases and their ephrin ligands regulate cell navigation during normal and oncogenic development. Signaling of Ephs is initiated in a multistep process leading to the assembly of higher-order signaling clusters that set off bidirectional signaling in interacting cells ...
Eph receptor tyrosine kinases and their ephrin ligands regulate cell navigation during normal and oncogenic development. Signaling of Ephs is initiated in a multistep process leading to the assembly of higher-order signaling clusters that set off bidirectional signaling in interacting cells. However, the structural and mechanistic details of this assembly remained undefined. Here we present high-resolution structures of the complete EphA2 ectodomain and complexes with ephrin-A1 and A5 as the base unit of an Eph cluster. The structures reveal an elongated architecture with novel Eph/Eph interactions, both within and outside of the Eph ligand-binding domain, that suggest the molecular mechanism underlying Eph/ephrin clustering. Structure-function analysis, by using site-directed mutagenesis and cell-based signaling assays, confirms the importance of the identified oligomerization interfaces for Eph clustering.
Related Citations:
Recruitment of Eph receptors into signaling clusters does not require ephrin contact. Wimmer-Kleikamp, S.H., Janes, P.W., Squire, A., Bastiaens, P.I., Lackmann, M. (2004) J Cell Biol 164: 661
Distinct subdomains of the EphA3 receptor mediate ligand binding and receptor dimerization. Lackmann, M., Oates, A.C., Dottori, M., Smith, F.M., Do, C., Power, M., Kravets, L., Boyd, A.W. (1998) J Biol Chem 273: 20228
Crystal structure of an Eph receptor-ephrin complex. Himanen, J.P., Rajashankar, K.R., Lackmann, M., Cowan, C.A., Henkemeyer, M., Nikolov, D.B. (2001) Nature 414: 933
Organizational Affiliation:
Structural Biology Program, Memorial Sloan-Kettering Cancer Center, 1275 York Avenue, New York, NY 10065, USA.
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