CPEB-mediated ZO-1 mRNA localization is required for epithelial tight-junction assembly and cell polarity

Nat Commun. 2012 Feb 14;3:675. doi: 10.1038/ncomms1678.


CPEB is a translational regulatory sequence-specific RNA-binding protein that controls germ cell development. Here we show that CPEB heterozygous female mice are fertile but contain disorganized mammary epithelial cells, in which zonal occludens-1 and claudin-3, apical tight-junction proteins, are mislocalized. CPEB depletion from mammary epithelial cells disrupts zonal occludens-1 apical localization and tight-junction distribution; conversely, ectopic expression of CPEB enhances zonal occludens-1 localization. CPEB and zonal occludens-1 mRNA are co-localized apically and zonal occludens-1 3' untranslated region-binding sites for CPEB are necessary for RNA localization. In a three-dimensional culture system that models lumen-containing mammary ducts, depletion of CPEB or zonal occludens-1 impairs central cavity formation, indicating a loss of cell polarity. Cavity formation in zonal occludens-1-depleted cells is rescued when they are transduced with zonal occludens-1 mRNA containing, but not lacking, CPEB-binding sites. Our data demonstrate that CPEB-mediated zonal occludens-1 mRNA localization is essential for tight-junction assembly and mammary epithelial cell polarity.

Publication types

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

MeSH terms

  • 3' Untranslated Regions
  • Animals
  • Binding Sites
  • Caco-2 Cells
  • Cell Polarity / genetics
  • Claudin-3
  • Claudins / metabolism
  • Dogs
  • Epithelium / metabolism*
  • Female
  • Gene Expression Regulation*
  • Heterozygote
  • Humans
  • Mammary Glands, Animal
  • Membrane Proteins / metabolism*
  • Mice
  • Mice, Knockout
  • Oocytes / cytology
  • Phosphoproteins / metabolism*
  • RNA, Messenger / metabolism
  • Tight Junctions / metabolism*
  • Transcription Factors / metabolism*
  • Zonula Occludens-1 Protein
  • mRNA Cleavage and Polyadenylation Factors / metabolism*


  • 3' Untranslated Regions
  • CLDN3 protein, human
  • CPEB1 protein, human
  • Claudin-3
  • Claudins
  • Cldn3 protein, mouse
  • Membrane Proteins
  • Phosphoproteins
  • RNA, Messenger
  • TJP1 protein, human
  • Tjp1 protein, mouse
  • Transcription Factors
  • Zonula Occludens-1 Protein
  • mRNA Cleavage and Polyadenylation Factors