title: A New Method to Study Heterodimerization of Membrane Proteins and Its Application to Fibroblast Growth Factor Receptors.
abstract: The activity of receptor tyrosine kinases (RTKs) is controlled through their lateral association in the plasma membrane. RTKs are believed to form both homodimers and heterodimers, and the different dimers are believed to play unique roles in cell signaling. However, RTK heterodimers remain poorly characterized, as compared with homodimers, because of limitations in current experimental methods. Here, we develop a FRET-based methodology to assess the thermodynamics of hetero-interactions in the plasma membrane. To demonstrate the utility of the methodology, we use it to study the hetero-interactions between three fibroblast growth factor receptors-FGFR1, FGFR2, and FGFR3-in the absence of ligand. Our results show that all possible FGFR heterodimers form, suggesting that the biological roles of FGFR heterodimers may be as significant as the homodimer roles. We further investigate the effect of two pathogenic point mutations in FGFR3 (A391E and G380R) on heterodimerization. We show that each of these mutations stabilize most of the heterodimers, with the largest effects observed for FGFR3 wild-type/mutant heterodimers. We thus demonstrate that the methodology presented here can yield new knowledge about RTK interactions and can further our understanding of signal transduction across the plasma membrane.
authors.affiliation: From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218.
authors.forename: Nuala
authors.initials: N
authors.lastname: Del Piccolo
authors.affiliation: From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218.
authors.forename: Sarvenaz
authors.initials: S
authors.lastname: Sarabipour
authors.affiliation: From the Department of Materials Science & Engineering, The Johns Hopkins University, Baltimore, Maryland 21218 kh@jhu.edu.
authors.forename: Kalina
authors.initials: K
authors.lastname: Hristova
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D016466:CHO Cells; D002462:Cell Membrane / Q000235:genetics / Q000378:metabolism; D006224:Cricetinae; D003412:Cricetulus; D031541:Fluorescence Resonance Energy Transfer / Q000379:methods*; D006801:Humans; D020125:Mutation, Missense; D055503:Protein Multimerization; D051496:Receptor, Fibroblast Growth Factor, Type 1 / Q000235:genetics / Q000378:metabolism*; D051497:Receptor, Fibroblast Growth Factor, Type 2 / Q000235:genetics / Q000378:metabolism*; D051498:Receptor, Fibroblast Growth Factor, Type 3 / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction
chemical_list: C496348:FGFR1 protein, human; C496353:FGFR2 protein, human; C496365:FGFR3 protein, human; D051496:Receptor, Fibroblast Growth Factor, Type 1; D051497:Receptor, Fibroblast Growth Factor, Type 2; D051498:Receptor, Fibroblast Growth Factor, Type 3
keywords: dimerization; fluorescence resonance energy transfer (FRET); membrane protein; protein-protein interaction; receptor tyrosine kinase; thermodynamics