title: Integrative nuclear FGFR1 signaling (INFS) pathway mediates activation of the tyrosine hydroxylase gene by angiotensin II, depolarization and protein kinase C.
abstract: The integrative nuclear FGFR1 signaling (INFS) pathway functions in association with cellular growth, differentiation, and regulation of gene expression, and is activated by diverse extracellular signals. Here we show that stimulation of angiotensin II (AII) receptors, depolarization, or activation protein kinase C (PKC) or adenylate cyclase all lead to nuclear accumulation of fibroblast growth factor 2 (FGF-2) and FGFR1, association of FGFR1 with splicing factor-rich domains, and activation of the tyrosine hydroxylase (TH) gene promoter in bovine adrenal medullary cells (BAMC). The up-regulation of endogenous TH protein or a transfected TH promoter-luciferase construct by AII, veratridine, or PMA (but not by forskolin) is abolished by transfection with a dominant negative FGFR1TK-mutant which localizes to the nucleus and plasma membrane, but not by extracellularly acting FGFR1 antagonists suramin and inositolhexakisphosphate (IP6). Mechanism of TH gene activation by FGF-2 and FGFR1 was further investigated in BAMC and human TE671 cultures. TH promoter was activated by co-transfected HMW FGF-2 (which is exclusively nuclear) but not by cytoplasmic FGF-1 or extracellular FGFs. Promoter transactivation by HMWFGF-2 was accompanied by an up-regulation of FGFR1 specifically in the cell nucleus and was prevented FGFR1(TK-) but not by IP6 or suramin. The TH promoter was also transactivated by co-transfected wild-type FGFR1, which localizes to both to the nucleus and the plasma membrane, and by an exclusively nuclear, soluble FGFR1(SP-/NLS) mutant with an inserted nuclear localization signal. Activation of the TH promoter by nuclear FGFR1 and FGF-2 was mediated through the cAMP-responsive element (CRE) and was associated with induction of CREB- and CBP/P-300-containing CRE complexes. We propose a new model for gene regulation in which nuclear FGFR1 acts as a mediator of CRE transactivation by AII, cell depolarization, and PKC.
authors.affiliation: Department of Pathology and Anatomical Sciences, Molecular and Structural Neurobiology and Gene Therapy Program, State University of New York, Buffalo, New York 14214-3000, USA.
authors.forename: Hu
authors.initials: H
authors.lastname: Peng
authors.forename: Jason
authors.initials: J
authors.lastname: Myers
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Fang
authors.forename: Ewa K
authors.initials: EK
authors.lastname: Stachowiak
authors.forename: Pamela A
authors.initials: PA
authors.lastname: Maher
authors.forename: Gabriel G
authors.initials: GG
authors.lastname: Martins
authors.forename: Gabriela
authors.initials: G
authors.lastname: Popescu
authors.forename: Ronald
authors.initials: R
authors.lastname: Berezney
authors.forename: Michal K
authors.initials: MK
authors.lastname: Stachowiak
mesh_terms: D000313:Adrenal Medulla / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D015153:Blotting, Western; D002417:Cattle; D002467:Cell Nucleus / Q000378:metabolism; D016764:Cell Polarity / Q000502:physiology; D002478:Cells, Cultured; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D011401:Promoter Regions, Genetic / Q000502:physiology; D011493:Protein Kinase C / Q000378:metabolism*; D020794:Receptor Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D051496:Receptor, Fibroblast Growth Factor, Type 1; D017468:Receptors, Fibroblast Growth Factor / Q000235:genetics / Q000378:metabolism*; D020218:Response Elements / Q000502:physiology; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology*; D015533:Transcriptional Activation / Q000502:physiology; D014162:Transfection; D014446:Tyrosine 3-Monooxygenase / Q000235:genetics*
chemical_list: D017468:Receptors, Fibroblast Growth Factor; D016222:Fibroblast Growth Factor 2; D000804:Angiotensin II; D014446:Tyrosine 3-Monooxygenase; D020794:Receptor Protein-Tyrosine Kinases; D051496:Receptor, Fibroblast Growth Factor, Type 1; D011493:Protein Kinase C