The tight junction protein complex undergoes rapid and continuous molecular remodeling at steady state

J Cell Biol. 2008 May 19;181(4):683-95. doi: 10.1083/jcb.200711165. Epub 2008 May 12.


The tight junction defines epithelial organization. Structurally, the tight junction is comprised of transmembrane and membrane-associated proteins that are thought to assemble into stable complexes to determine function. In this study, we measure tight junction protein dynamics in live confluent Madin-Darby canine kidney monolayers using fluorescence recovery after photobleaching and related methods. Mathematical modeling shows that the majority of claudin-1 (76 +/- 5%) is stably localized at the tight junction. In contrast, the majority of occludin (71 +/- 3%) diffuses rapidly within the tight junction with a diffusion constant of 0.011 microm(2)s(-1). Zonula occludens-1 molecules are also highly dynamic in this region, but, rather than diffusing within the plane of the membrane, 69 +/- 5% exchange between membrane and intracellular pools in an energy-dependent manner. These data demonstrate that the tight junction undergoes constant remodeling and suggest that this dynamic behavior may contribute to tight junction assembly and regulation.

Publication types

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

MeSH terms

  • Animals
  • Cell Line
  • Cell Membrane / metabolism
  • Cell Polarity
  • Claudin-1
  • Computational Biology
  • Computer Simulation
  • Diffusion
  • Dogs
  • Epithelial Cells / cytology
  • Fluorescence Recovery After Photobleaching
  • Humans
  • Membrane Proteins / metabolism*
  • Models, Biological*
  • Multiprotein Complexes / chemistry
  • Multiprotein Complexes / metabolism
  • Occludin
  • Phosphoproteins / metabolism
  • Tight Junctions / chemistry*
  • Tight Junctions / metabolism*
  • Zonula Occludens-1 Protein


  • CLDN1 protein, human
  • Claudin-1
  • Membrane Proteins
  • Multiprotein Complexes
  • OCLN protein, human
  • Occludin
  • Phosphoproteins
  • TJP1 protein, human
  • Zonula Occludens-1 Protein