title: The transmembrane protein XFLRT3 forms a complex with FGF receptors and promotes FGF signalling.
abstract: Fibroblast growth factors (FGFs) signal through high-affinity tyrosine kinase receptors to regulate a diverse range of cellular processes, including cell growth, differentiation and migration, as well as cell death. Here we identify XFLRT3, a member of a leucine-rich-repeat transmembrane protein family, as a novel modulator of FGF signalling. XFLRT3 is co-expressed with FGFs, and its expression is both induced after activation and downregulated after inhibition of FGF signalling. In gain- and loss-of function experiments, FLRT3 and FLRT2 phenocopy FGF signalling in Xenopus laevis. XFLRT3 signalling results in phosphorylation of ERK and is blocked by MAPK phosphatase 1, but not by expression of a dominant-negative phosphatidyl inositol 3-OH kinase (PI(3)K) mutant. XFLRT3 interacts with FGF receptors (FGFRs) in co-immunoprecipitation experiments in vitro and in bioluminescence resonance energy transfer assays in vivo. The results indicate that XFLRT3 is a transmembrane modulator of FGF-MAP kinase signalling in vertebrates.
authors.affiliation: Division of Molecular Embryology, Deutsches Krebsforschungszentrum, Im Neuenheimer Feld 280, D-69120 Heidelberg, Germany.
authors.forename: Ralph T
authors.initials: RT
authors.lastname: Böttcher
authors.forename: Nicolas
authors.initials: N
authors.lastname: Pollet
authors.forename: Hajo
authors.initials: H
authors.lastname: Delius
authors.forename: Christof
authors.initials: C
authors.lastname: Niehrs
mesh_terms: D000818:Animals; D001483:Base Sequence / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D002462:Cell Membrane / Q000378:metabolism; D002478:Cells, Cultured; D018076:DNA, Complementary / Q000032:analysis / Q000235:genetics; D015536:Down-Regulation / Q000235:genetics; D054638:Dual Specificity Phosphatase 1; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D004627:Embryonic Induction / Q000235:genetics; D025461:Feedback, Physiological / Q000235:genetics; D005346:Fibroblast Growth Factors / Q000378:metabolism*; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology; D008565:Membrane Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008969:Molecular Sequence Data; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D054645:Protein Phosphatase 1; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism / Q000494:pharmacology; D017468:Receptors, Fibroblast Growth Factor / Q000378:metabolism*; D029867:Xenopus Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D014982:Xenopus laevis / Q000196:embryology* / Q000378:metabolism
chemical_list: D018076:DNA, Complementary; C542073:FLRT3 protein, Xenopus; D008565:Membrane Proteins; D017468:Receptors, Fibroblast Growth Factor; D029867:Xenopus Proteins; D005346:Fibroblast Growth Factors; D019869:Phosphatidylinositol 3-Kinases; D020928:Mitogen-Activated Protein Kinases; D054645:Protein Phosphatase 1; C517019:DUSP1 protein, human; D054638:Dual Specificity Phosphatase 1; D017027:Protein Tyrosine Phosphatases