title: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and forster resonance energy transfer suggest weak interactions between fibroblast growth factor receptor 3 (FGFR3) transmembrane domains in the absence of extracellular domains and ligands.
abstract: Lateral dimerization of membrane proteins has evolved as a means of signal transduction across the plasma membrane for all receptor tyrosine kinases (RTKs). The transmembrane (TM) domains of RTKs are proposed to play an important role in the dimerization process. We have investigated whether the TM domains of one RTK, fibroblast growth factor receptor 3 (FGFR3), dimerize in lipid vesicles in the absence of the extracellular domains and ligands. We have performed sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with peptides produced via solid-phase peptide synthesis that correspond to the TM domain of FGFR3. We have carried out Forster resonance energy transfer (FRET) measurements using two donor-acceptor pairs, fluorescein/rhodamine and Cy3/Cy5, as a function of peptide concentration and donor-to-acceptor mole ratios. Our results suggest that FGFR3 TM domains form sequence-specific dimers in lipid bilayers. However, the dimerization propensity of FGFR3 TM domain is much weaker than the dimerization propensity of glycophorin A (GpA), the well-characterized "membrane dimer standard". We discuss our findings in the context of cell signaling across the plasma membrane and diseases or disorders that occur due to single amino acid mutations in the TM domain of FGFR3.
authors.affiliation: Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218, USA.
authors.forename: Edwin
authors.initials: E
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: You
authors.forename: Kalina
authors.initials: K
authors.lastname: Hristova
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002462:Cell Membrane / Q000737:chemistry; D002942:Circular Dichroism; D019281:Dimerization; D004591:Electrophoresis, Polyacrylamide Gel; D031541:Fluorescence Resonance Energy Transfer; D008024:Ligands; D008969:Molecular Sequence Data; D010446:Peptide Fragments / Q000737:chemistry; D011505:Protein-Tyrosine Kinases / Q000737:chemistry* / Q000302:isolation & purification; D051498:Receptor, Fibroblast Growth Factor, Type 3; D017468:Receptors, Fibroblast Growth Factor / Q000737:chemistry* / Q000302:isolation & purification; D019032:Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
chemical_list: D008024:Ligands; D010446:Peptide Fragments; D017468:Receptors, Fibroblast Growth Factor; D011505:Protein-Tyrosine Kinases; D051498:Receptor, Fibroblast Growth Factor, Type 3