Tuning Cytokine Receptor Signaling by Re-orienting Dimer Geometry with Surrogate Ligands

• Published in: Cell 2015-03, Vol.160 (6), p.1196-1208
• Main Authors: Moraga, Ignacio, Wernig, Gerlinde, Wilmes, Stephan, Gryshkova, Vitalina, Richter, Christian P., Hong, Wan-Jen, Sinha, Rahul, Guo, Feng, Fabionar, Hyna, Wehrman, Tom S., Krutzik, Peter, Demharter, Samuel, Plo, Isabelle, Weissman, Irving L., Minary, Peter, Majeti, Ravindra, Constantinescu, Stefan N., Piehler, Jacob, Garcia, K. Christopher
• Format: Article
• Language: English
• Subjects: Amino Acid Sequence; Animals; Antibodies, Monoclonal - chemistry; Antibodies, Monoclonal - genetics; Antibodies, Monoclonal - metabolism; Cell Line; Crystallography, X-Ray; Dimerization; Erythropoietin - metabolism; Humans; Janus Kinase 2 - genetics; Janus Kinase 2 - metabolism; Mice; Models, Molecular; Molecular Dynamics Simulation; Molecular Sequence Data; Point Mutation; Protein Engineering; Receptors, Erythropoietin - agonists; Receptors, Erythropoietin - antagonists & inhibitors; Receptors, Erythropoietin - chemistry; Receptors, Erythropoietin - metabolism; Sequence Alignment; Signal Transduction
• ISSN: 0092-8674; 1097-4172
• DOI: 10.1016/j.cell.2015.02.011

Most cell-surface receptors for cytokines and growth factors signal as dimers, but it is unclear whether remodeling receptor dimer topology is a viable strategy to “tune” signaling output. We utilized diabodies (DA) as surrogate ligands in a prototypical dimeric receptor-ligand system, the cytokine Erythropoietin (EPO) and its receptor (EpoR), to dimerize EpoR ectodomains in non-native architectures. Diabody-induced signaling amplitudes varied from full to minimal agonism, and structures of these DA/EpoR complexes differed in EpoR dimer orientation and proximity. Diabodies also elicited biased or differential activation of signaling pathways and gene expression profiles compared to EPO. Non-signaling diabodies inhibited proliferation of erythroid precursors from patients with a myeloproliferative neoplasm due to a constitutively active JAK2V617F mutation. Thus, intracellular oncogenic mutations causing ligand-independent receptor activation can be counteracted by extracellular ligands that re-orient receptors into inactive dimer topologies. This approach has broad applications for tuning signaling output for many dimeric receptor systems. [Display omitted] •Ligand-driven re-orientation of receptor dimer topology tunes signaling output•Diabodies elicit differential signal activation•Non-agonistic diabodies counteract intracellular oncogenic signaling Synthetic ligands called diabodies can change the amplitude and nature of signal activation, or counteract oncogenic ligand-independent intracellular signaling, by re-orienting the geometry of receptor dimerization.