Orchestration of ErbB3 signaling through heterointeractions and homointeractions

• Published in: Molecular biology of the cell Vol. 26; no. 22; pp. 4109 - 4123
• Main Authors: McCabe Pryor, Meghan, Steinkamp, Mara P, Halasz, Adam M, Chen, Ye, Yang, Shujie, Smith, Marilyn S, Zahoransky-Kohalmi, Gergely, Swift, Mark, Xu, Xiao-Ping, Hanein, Dorit, Volkmann, Niels, Lidke, Diane S, Edwards, Jeremy S, Wilson, Bridget S
• Format: Journal Article
• Language: English
• Published: United States American Society for Cell Biology 05.11.2015; The American Society for Cell Biology
• Subjects: BASIC BIOLOGICAL SCIENCES; Cell Biology; Computer Simulation; Humans; Ligands; Models, Biological; Phosphorylation; Protein Interaction Domains and Motifs; Protein Multimerization; Receptor Protein-Tyrosine Kinases - metabolism; Receptor, ErbB-3 - metabolism; Signal Transduction
• ISSN: 1059-1524; 1939-4586
• DOI: 10.1091/mbc.e14-06-1114

Members of the ErbB family of receptor tyrosine kinases are capable of both homointeractions and heterointeractions. Because each receptor has a unique set of binding sites for downstream signaling partners and differential catalytic activity, subtle shifts in their combinatorial interplay may have a large effect on signaling outcomes. The overexpression and mutation of ErbB family members are common in numerous human cancers and shift the balance of activation within the signaling network. Here we report the development of a spatial stochastic model that addresses the dynamics of ErbB3 homodimerization and heterodimerization with ErbB2. The model is based on experimental measures for diffusion, dimer off-rates, kinase activity, and dephosphorylation. We also report computational analysis of ErbB3 mutations, generating the prediction that activating mutations in the intracellular and extracellular domains may be subdivided into classes with distinct underlying mechanisms. We show experimental evidence for an ErbB3 gain-of-function point mutation located in the C-lobe asymmetric dimerization interface, which shows enhanced phosphorylation at low ligand dose associated with increased kinase activity.