A Common Docking Domain in Progesterone Receptor-B links DUSP6 and CK2 signaling to proliferative transcriptional programs in breast cancer cells

Nucleic Acids Res. 2013 Oct;41(19):8926-42. doi: 10.1093/nar/gkt706. Epub 2013 Aug 5.

Abstract

Progesterone receptors (PR) are transcription factors relevant to breast cancer biology. Herein, we describe an N-terminal common docking (CD) domain in PR-B, a motif first described in mitogen-activated protein kinases. Binding studies revealed PR-B interacts with dual-specificity phosphatase 6 (DUSP6) via the CD domain. Mutation of the PR-B CD domain (mCD) attenuated cell cycle progression and expression of PR-B target genes (including STAT5A and Wnt1); mCD PR-B failed to undergo phosphorylation on Ser81, a ck2-dependent site required for expression of these genes. PR-B Ser81 phosphorylation was dependent on binding with DUSP6 and required for recruitment of a transcriptional complex consisting of PR-B, DUSP6 and ck2 to an enhancer region upstream of the Wnt1 promoter. STAT5 was present at this site in the absence or presence of progestin. Furthermore, phospho-Ser81 PR-B was recruited to the STAT5A gene upon progestin treatment, suggestive of a feed-forward mechanism. Inhibition of JAK/STAT-signaling blocked progestin-induced STAT5A and Wnt1 expression. Our studies show that DUSP6 serves as a scaffold for ck2-dependent PR-B Ser81 phosphorylation and subsequent PR-B-specific gene selection in coordination with STAT5. Coregulation of select target genes by PR-B and STAT5 is likely a global mechanism required for growth promoting programs relevant to mammary stem cell biology and cancer.

Publication types

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

MeSH terms

  • Breast Neoplasms / enzymology
  • Breast Neoplasms / genetics*
  • Breast Neoplasms / metabolism
  • Casein Kinase II / metabolism*
  • Cell Line, Tumor
  • Cell Proliferation
  • Dual Specificity Phosphatase 6 / metabolism*
  • Enhancer Elements, Genetic
  • Female
  • Gene Expression Regulation, Neoplastic*
  • Humans
  • Janus Kinases / metabolism
  • Phosphorylation
  • Progestins / pharmacology
  • Protein Interaction Domains and Motifs
  • Receptors, Progesterone / chemistry
  • Receptors, Progesterone / metabolism*
  • S Phase
  • STAT Transcription Factors / metabolism
  • STAT5 Transcription Factor / genetics
  • STAT5 Transcription Factor / metabolism
  • Serine / metabolism
  • Signal Transduction
  • Transcription, Genetic
  • Wnt1 Protein / genetics
  • Wnt1 Protein / metabolism

Substances

  • Progestins
  • Receptors, Progesterone
  • STAT Transcription Factors
  • STAT5 Transcription Factor
  • Wnt1 Protein
  • progesterone receptor B
  • Serine
  • Janus Kinases
  • Casein Kinase II
  • DUSP6 protein, human
  • Dual Specificity Phosphatase 6