title: Phosphoproteomic identification of a PDX-1/14-3-3ε interaction in pancreatic beta cells.
abstract: Glucose-dependent activation of the homeodomain transcription factor PDX-1 leads to its phosphorylation, to an increase in DNA binding capacity, and to NLS dependent translocation into the nucleus. To uncover unknown mediators of PDX-1 activation, PDX-1 interacting proteins were analysed by pull-down from (32)P-labelled, glucose-stimulated MIN6 cells. Recovered proteins were analysed by 2D gel electrophoresis and mass spectrometry. We identified 14-3-3ε as a novel PDX-1 binding protein and confirmed the interaction in vivo by Fluorescence Resonance Energy Transfer (FRET) analysis. We propose that 14-3-3ε interacts directly with PDX-1 to regulate its cellular distribution in pancreatic beta cells.
authors.affiliation: Department of Medical Biochemistry and Molecular Biology, University of Greifswald, Greifswald, Germany.
authors.forename: P
authors.initials: P
authors.lastname: Ziegler
authors.forename: S
authors.initials: S
authors.lastname: Teller
authors.forename: N H
authors.initials: NH
authors.lastname: Ha
authors.forename: B
authors.initials: B
authors.lastname: Giese
authors.forename: M
authors.initials: M
authors.lastname: Fraunholz
authors.forename: R
authors.initials: R
authors.lastname: Walther
mesh_terms: D048948:14-3-3 Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D045744:Cell Line, Tumor; D015180:Electrophoresis, Gel, Two-Dimensional; D018398:Homeodomain Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D050417:Insulin-Secreting Cells / Q000737:chemistry / Q000378:metabolism*; D013058:Mass Spectrometry; D051379:Mice; D010766:Phosphorylation; D011485:Protein Binding; D040901:Proteomics; D015534:Trans-Activators / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*
chemical_list: D048948:14-3-3 Proteins; D018398:Homeodomain Proteins; D015534:Trans-Activators; C084010:pancreatic and duodenal homeobox 1 protein