Phosphorylation of poly(rC) binding protein 1 (PCBP1) contributes to stabilization of mu opioid receptor (MOR) mRNA via interaction with AU-rich element RNA-binding protein 1 (AUF1) and poly A binding protein (PABP)

Gene. 2017 Jan 20:598:113-130. doi: 10.1016/j.gene.2016.11.003. Epub 2016 Nov 9.

Abstract

Gene regulation at the post-transcriptional level is frequently based on cis- and trans-acting factors on target mRNAs. We found a C-rich element (CRE) in mu-opioid receptor (MOR) 3'-untranslated region (UTR) to which poly (rC) binding protein 1 (PCBP1) binds, resulting in MOR mRNA stabilization. RNA immunoprecipitation and RNA EMSA revealed the formation of PCBP1-RNA complexes at the element. Knockdown of PCBP1 decreased MOR mRNA half-life and protein expression. Stimulation by forskolin increased cytoplasmic localization of PCBP1 and PCBP1/MOR 3'-UTR interactions via increased serine phosphorylation that was blocked by protein kinase A (PKA) or (phosphatidyl inositol-3) PI3-kinase inhibitors. The forskolin treatment also enhanced serine- and tyrosine-phosphorylation of AU-rich element binding protein (AUF1), concurrent with its increased binding to the CRE, and led to an increased interaction of poly A binding protein (PABP) with the CRE and poly(A) sites. AUF1 phosphorylation also led to an increased interaction with PCBP1. These findings suggest that a single co-regulator, PCBP1, plays a crucial role in stabilizing MOR mRNA, and is induced by PKA signaling by conforming to AUF1 and PABP.

Keywords: 3′-Untranslated region; Mu opioid receptor; Protein kinase A signaling; RNA binding protein; RNA stability.

MeSH terms

  • 3' Untranslated Regions
  • Binding Sites / genetics
  • Cell Line, Tumor
  • Colforsin / pharmacology
  • DNA-Binding Proteins
  • Gene Knockdown Techniques
  • Heterogeneous Nuclear Ribonucleoprotein D0
  • Heterogeneous-Nuclear Ribonucleoprotein D / metabolism*
  • Heterogeneous-Nuclear Ribonucleoproteins / antagonists & inhibitors
  • Heterogeneous-Nuclear Ribonucleoproteins / genetics
  • Heterogeneous-Nuclear Ribonucleoproteins / metabolism*
  • Humans
  • Models, Biological
  • Phosphorylation
  • Poly(A)-Binding Proteins / metabolism*
  • RNA Processing, Post-Transcriptional
  • RNA Stability
  • RNA, Messenger / genetics*
  • RNA, Messenger / metabolism*
  • RNA-Binding Proteins
  • Receptors, Opioid, mu / genetics*
  • Receptors, Opioid, mu / metabolism
  • Up-Regulation

Substances

  • 3' Untranslated Regions
  • DNA-Binding Proteins
  • HNRNPD protein, human
  • Heterogeneous Nuclear Ribonucleoprotein D0
  • Heterogeneous-Nuclear Ribonucleoprotein D
  • Heterogeneous-Nuclear Ribonucleoproteins
  • OPRM1 protein, human
  • PCBP1 protein, human
  • Poly(A)-Binding Proteins
  • RNA, Messenger
  • RNA-Binding Proteins
  • Receptors, Opioid, mu
  • Colforsin