Palmitoylation regulates 17β-estradiol-induced estrogen receptor-α degradation and transcriptional activity

Mol Endocrinol. 2012 May;26(5):762-74. doi: 10.1210/me.2011-1208. Epub 2012 Mar 22.

Abstract

The estrogen receptor-α (ERα) is a transcription factor that regulates gene expression through the binding to its cognate hormone 17β-estradiol (E2). ERα transcriptional activity is regulated by E2-evoked 26S proteasome-mediated ERα degradation and ERα serine (S) residue 118 phosphorylation. Furthermore, ERα mediates fast cell responses to E2 through the activation of signaling cascades such as the MAPK/ERK and phosphoinositide-3-kinase/v-akt murine thymoma viral oncogene homolog 1 pathways. These E2 rapid effects require a population of the ERα located at the cell plasma membrane through palmitoylation, a dynamic enzymatic modification mediated by palmitoyl-acyl-transferases. However, whether membrane-initiated and transcriptional ERα activities integrate in a unique picture or represent parallel pathways still remains to be firmly clarified. Hence, we evaluated here the impact of ERα palmitoylation on E2-induced ERα degradation and S118 phosphorylation. The lack of palmitoylation renders ERα more susceptible to E2-dependent degradation, blocks ERα S118 phosphorylation and prevents E2-induced ERα estrogen-responsive element-containing promoter occupancy. Consequently, ERα transcriptional activity is prevented and the receptor addressed to the nuclear matrix subnuclear compartment. These data uncover a circuitry in which receptor palmitoylation links E2-dependent ERα degradation, S118 phosphorylation, and transcriptional activity in a unique molecular mechanism. We propose that rapid E2-dependent signaling could be considered as a prerequisite for ERα transcriptional activity and suggest an integrated model of ERα intracellular signaling where E2-dependent early extranuclear effects control late receptor-dependent nuclear actions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acyltransferases / antagonists & inhibitors
  • Cathepsin D / genetics
  • Cathepsin D / metabolism
  • Cell Line
  • Enzyme Inhibitors / pharmacology
  • Estradiol / pharmacology*
  • Estrogen Receptor alpha / genetics
  • Estrogen Receptor alpha / metabolism*
  • Estrogens / pharmacology*
  • Female
  • Humans
  • Lipoylation / drug effects*
  • Palmitates / pharmacology
  • Palmitic Acid / metabolism*
  • Phosphorylation / drug effects
  • Presenilin-2 / genetics
  • Presenilin-2 / metabolism
  • Protein Processing, Post-Translational / drug effects*
  • Proteolysis / drug effects
  • RNA, Messenger / metabolism
  • Response Elements / drug effects
  • Serine / metabolism
  • Signal Transduction / drug effects
  • Transcriptional Activation / drug effects*

Substances

  • ESR1 protein, human
  • Enzyme Inhibitors
  • Estrogen Receptor alpha
  • Estrogens
  • PSEN2 protein, human
  • Palmitates
  • Presenilin-2
  • RNA, Messenger
  • 2-bromopalmitate
  • Palmitic Acid
  • Serine
  • Estradiol
  • Acyltransferases
  • HHAT protein, human
  • CTSD protein, human
  • Cathepsin D