Membrane-initiated estradiol signaling increases tyrosine hydroxylase promoter activity with ER alpha in PC12 cells

J Neurochem. 2010 Jan;112(1):42-55. doi: 10.1111/j.1471-4159.2009.06430.x. Epub 2009 Oct 10.

Abstract

Tyrosine hydroxylase (TH) promoter activity is induced by 17beta-estradiol (E(2)) in PC12 cells expressing estradiol receptor-alpha (ERalpha) requiring a cAMP/calcium response element (CRE/CaRE) at -45. To examine whether membrane-initiated estradiol signaling is underlying this induction, cells co-transfected with TH reporter construct and ERalpha expression vector were exposed to membrane-impermeant estradiol conjugate (beta-estradiol-6-(O-carboxy-methyl) oxime-bovine serum albumin, E(2)BSA). TH promoter activity was elevated by E(2)BSA in dose- and time-dependent manner. E(2)BSA also elicited rapid phosphorylation of CRE binding protein (CREB) and increased CRE-driven promoter activity. Over-expression of dominant negative forms of CREB, with mutations in DNA binding or phosphorylation site, prevented TH promoter response to E(2)BSA. Pre-treatment with protein kinase A (PKA) and MEK inhibitors reduced E(2) dependent phosphorylation of CREB and ERK, and also decreased induction of TH promoter activity by E(2) or E(2)BSA. Blocking S-palmitoylation of ERalpha with C451A mutation and/or pre-treatment with 2-Bromopalmitate did not prevent but instead enhanced E(2) or E(2)BSA-elicited induction of TH promoter activity. These findings reveal, for the first time, that estradiol induction of TH gene transcription with ERalpha in PC12 cells involves membrane-initiated estradiol signaling, rapid activation of dual PKA/MEK signaling pathways, leading to CREB phosphorylation, acting at CRE/CaRE. The data demonstrate possible mechanism whereby estradiol affects catecholaminergic systems in vivo.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • CREB-Binding Protein / biosynthesis
  • CREB-Binding Protein / genetics
  • CREB-Binding Protein / metabolism
  • Cattle
  • Down-Regulation / genetics
  • Enzyme Induction / genetics
  • Estradiol / physiology*
  • Estrogen Receptor alpha / biosynthesis
  • Estrogen Receptor alpha / genetics
  • Estrogen Receptor alpha / physiology*
  • Membrane Proteins / biosynthesis
  • Membrane Proteins / genetics
  • Membrane Proteins / physiology*
  • Mice
  • Mutation
  • PC12 Cells
  • Phosphorylation / genetics
  • Promoter Regions, Genetic / physiology*
  • Rats
  • Signal Transduction / genetics
  • Signal Transduction / physiology*
  • Transcriptional Activation / genetics
  • Transcriptional Activation / physiology*
  • Tyrosine 3-Monooxygenase / biosynthesis
  • Tyrosine 3-Monooxygenase / genetics*
  • Tyrosine 3-Monooxygenase / metabolism*
  • Up-Regulation / genetics

Substances

  • Estrogen Receptor alpha
  • Membrane Proteins
  • Estradiol
  • Tyrosine 3-Monooxygenase
  • CREB-Binding Protein