title: PTH1R Mutants Found in Patients with Primary Failure of Tooth Eruption Disrupt G-Protein Signaling.
abstract: OBJECTIVE
  Primary failure of tooth eruption (PFE) is causally linked to heterozygous mutations of the parathyroid hormone receptor (PTH1R) gene. The mutants described so far lead to exchange of amino acids or truncation of the protein that may result in structural changes of the expressed PTH1R. However, functional effects of these mutations have not been investigated yet.
  
  
  METHODS
  In HEK293 cells, PTH1R wild type was co-transfected with selected PTH1R mutants identified in patients with PFE. The effects on activation of PTH-regulated intracellular signaling pathways were analyzed by ELISA and Western immunoblotting. Differential effects of wild type and mutated PTH1R on TRESK ion channel regulation were analyzed by electrophysiological recordings in Xenopus laevis oocytes.
  
  
  RESULTS
  In HEK293 cells, activation of PTH1R wild type increases cAMP and in response activates cAMP-stimulated protein kinase as detected by phosphorylation of the vasodilator stimulated phosphoprotein (VASP). In contrast, the PTH1R mutants are functionally inactive and mutant PTH1R/Gly452Glu has a dominant negative effect on the signaling of PTH1R wild type. Confocal imaging revealed that wild type PTH1R is expressed on the cell surface, whereas PTH1R/Gly452Glu mutant is mostly retained inside the cell. Furthermore, in contrast to wild type PTH1R which substantially augmented K+ currents of TRESK channels, coupling of mutated PTH1R to TRESK channels was completely abolished.
  
  
  CONCLUSIONS
  PTH1R mutations affect intracellular PTH-regulated signaling in vitro. In patients with primary failure of tooth eruption defective signaling of PTH1R mutations is suggested to occur in dento-alveolar cells and thus may lead to impaired tooth movement.
authors.affiliation: Institute of Clinical Biochemistry and Pathobiochemistry, University of Wuerzburg, Wuerzburg, Germany.|Institute of Experimental Cardiovascular Research, University Medical Centre Hamburg-Eppendorf, Hamburg, Germany.
authors.forename: Hariharan
authors.initials: H
authors.lastname: Subramanian
authors.affiliation: Institute of Physiology, AG Molecular Electrophysiology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Döring
authors.affiliation: Institute of Physiology, AG Molecular Electrophysiology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Sina
authors.initials: S
authors.lastname: Kollert
authors.affiliation: Institute of Clinical Biochemistry and Pathobiochemistry, University of Wuerzburg, Wuerzburg, Germany.|Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
authors.forename: Natalia
authors.initials: N
authors.lastname: Rukoyatkina
authors.affiliation: Institute of Physiology, AG Molecular Electrophysiology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Julia
authors.initials: J
authors.lastname: Sturm
authors.affiliation: Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.|Department of Cytology and Histology, St. Petersburg State University, St. Petersburg Russia.
authors.forename: Stepan
authors.initials: S
authors.lastname: Gambaryan
authors.affiliation: Department of Orthodontics, University Clinic of Wuerzburg, Wuerzburg, Germany.
authors.forename: Angelika
authors.initials: A
authors.lastname: Stellzig-Eisenhauer
authors.affiliation: Department of Orthodontics, University Clinic of Wuerzburg, Wuerzburg, Germany.|Department of Orthodontics, University Clinic of Goettingen, Goettingen, Germany.
authors.forename: Philipp
authors.initials: P
authors.lastname: Meyer-Marcotty
authors.affiliation: Institute of Clinical Biochemistry and Pathobiochemistry, University of Wuerzburg, Wuerzburg, Germany.|Department of Orthodontics, University Clinic of Wuerzburg, Wuerzburg, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Eigenthaler
authors.affiliation: Institute of Physiology, AG Molecular Electrophysiology, University of Wuerzburg, Wuerzburg, Germany.
authors.forename: Erhard
authors.initials: E
authors.lastname: Wischmeyer
mesh_terms: D000818:Animals; D015815:Cell Adhesion Molecules / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism; D004594:Electrophysiology; D019204:GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D005786:Gene Expression Regulation; D057809:HEK293 Cells; D006801:Humans; D008840:Microfilament Proteins / Q000378:metabolism; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009154:Mutation / Q000235:genetics*; D009865:Oocytes / Q000166:cytology / Q000378:metabolism; D010281:Parathyroid Hormone / Q000378:metabolism; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D044168:Receptor, Parathyroid Hormone, Type 1 / Q000235:genetics*; D015398:Signal Transduction; D014076:Tooth Diseases / Q000235:genetics / Q000473:pathology*; D014982:Xenopus laevis; D000098662:Vasodilator-Stimulated Phosphoprotein
chemical_list: D015815:Cell Adhesion Molecules; D008840:Microfilament Proteins; C473449:PTH1R protein, human; D010281:Parathyroid Hormone; D010750:Phosphoproteins; D044168:Receptor, Parathyroid Hormone, Type 1; D000098662:Vasodilator-Stimulated Phosphoprotein; D000242:Cyclic AMP; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D019204:GTP-Binding Proteins