Skip to main content

Thank you for visiting nature.com. You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

  • Letter
  • Published:

Par-3 controls tight junction assembly through the Rac exchange factor Tiam1

Abstract

The par (partitioning-defective) genes express a set of conserved proteins that function in polarization and asymmetric cell division1,2. Par-3 has multiple protein-interaction domains, and associates with Par-6 and atypical protein kinase C (aPKC)3,4,5. In Drosophila, Par-3 is essential for epithelial cell polarization6. However, its function in mammals is unclear. Here we show that depletion of Par-3 in mammalian epithelial cells profoundly disrupts tight junction assembly. Expression of a carboxy-terminal fragment plus the third PDZ domain of Par-3 partially rescues junction assembly, but neither Par-6 nor aPKC binding is required. Unexpectedly, Rac is constitutively activated in cells lacking Par-3, and the assembly of tight junctions is efficiently restored by a dominant-negative Rac mutant. The Rac exchange factor Tiam1 (ref. 7) binds directly to the carboxy-terminal region of Par-3, and knockdown of Tiam1 enhances tight junction formation in cells lacking Par-3. These results define a critical function for Par-3 in tight junction assembly, and reveal a novel mechanism through which Par-3 engages in the spatial regulation of Rac activity and establishment of epithelial polarity.

This is a preview of subscription content, access via your institution

Access options

Buy this article

Prices may be subject to local taxes which are calculated during checkout

Figure 1: Par-3 loss severely disrupts tight junction formation in MDCK II cells.
Figure 2: Rescue of tight junction assembly in Par-3-knockdown cells.
Figure 3: Inhibition of the Rho pathway rescues junction assembly.
Figure 4: Constitutive activation of Rac in Par-3-knockdown cells.
Figure 5: Par-3 regulates tight junction formation through interaction with Tiam1.

Similar content being viewed by others

Accession codes

Accessions

BINDPlus

References

  1. Kemphues, K. J., Priess, J. R., Morton, D. G. & Cheng, N. S. Identification of genes required for cytoplasmic localization in early C. elegans embryos. Cell 52, 311–320 (1988).

    Article  CAS  Google Scholar 

  2. Doe, C. Q. & Bowerman, B. Asymmetric cell division: fly neuroblast meets worm zygote. Curr. Opin. Cell Biol. 13, 68–75 (2001).

    Article  CAS  Google Scholar 

  3. Izumi, Y. et al. An atypical PKC directly associates and colocalizes at the epithelial tight junction with ASIP, a mammalian homologue of Caenorhabditis elegans polarity protein PAR-3. J. Cell Biol. 143, 95–106 (1998).

    Article  CAS  Google Scholar 

  4. Joberty, G., Petersen, C., Gao, L. & Macara, I. G. The cell-polarity protein Par6 links Par3 and atypical protein kinase C to Cdc42. Nature Cell Biol. 2, 531–539 (2000).

    Article  CAS  Google Scholar 

  5. Lin, D. et al. A mammalian PAR-3–PAR-6 complex implicated in Cdc42/Rac1 and aPKC signalling and cell polarity. Nature Cell Biol. 2, 540–547 (2000).

    Article  CAS  Google Scholar 

  6. Tepass, U., Tanentzapf, G., Ward, R. & Fehon, R. Epithelial cell polarity and cell junctions in Drosophila. Annu. Rev. Genet. 35, 747–784 (2001).

    Article  CAS  Google Scholar 

  7. Mertens, A. E., Roovers, R. C. & Collard, J. G. Regulation of Tiam1–Rac signalling. FEBS Lett. 546, 11–16 (2003).

    Article  CAS  Google Scholar 

  8. Macara, I. G. Parsing the polarity code. Nature Rev. Mol. Cell Biol. 5, 220–231 (2004).

    Article  CAS  Google Scholar 

  9. Nelson, W. J. Adaptation of core mechanisms to generate cell polarity. Nature 422, 766–774 (2003).

    Article  CAS  Google Scholar 

  10. Perez-Moreno, M., Jamora, C. & Fuchs, E. Sticky business: orchestrating cellular signals at adherens junctions. Cell 112, 535–548 (2003).

    Article  CAS  Google Scholar 

  11. Gibson, M. C. & Perrimon, N. Apicobasal polarization: epithelial form and function. Curr. Opin. Cell Biol. 15, 747–752 (2003).

    Article  CAS  Google Scholar 

  12. Hirose, T. et al. Involvement of ASIP/PAR-3 in the promotion of epithelial tight junction formation. J. Cell Sci. 115, 2485–2495 (2002).

    CAS  PubMed  Google Scholar 

  13. Matter, K. & Balda, M. S. Functional analysis of tight junctions. Methods 30, 228–234 (2003).

    Article  CAS  Google Scholar 

  14. Furuse, M., Furuse, K., Sasaki, H. & Tsukita, S. Conversion of zonulae occludentes from tight to leaky strand type by introducing claudin-2 into Madin-Darby canine kidney I cells. J. Cell Biol. 153, 263–272 (2001).

    Article  CAS  Google Scholar 

  15. Gao, L., Joberty, G. & Macara, I. G. Assembly of epithelial tight junctions is negatively regulated by Par6. Curr. Biol. 12, 221–225 (2002).

    Article  CAS  Google Scholar 

  16. Benton, R. & Johnston, D. S. A conserved oligomerization domain in Drosophila Bazooka/PAR-3 is important for apical localization and epithelial polarity. Curr. Biol. 13, 1330–1334 (2003).

    Article  CAS  Google Scholar 

  17. Mizuno, K. et al. Self-association of PAR-3-mediated by the conserved N-terminal domain contributes to the development of epithelial tight junctions. J. Biol. Chem. 278, 31240–31250 (2003).

    Article  CAS  Google Scholar 

  18. Wodarz, A., Ramrath, A., Grimm, A. & Knust, E. Drosophila atypical protein kinase C associates with Bazooka and controls polarity of epithelia and neuroblasts. J. Cell Biol. 150, 1361–1374 (2000).

    Article  CAS  Google Scholar 

  19. Ebnet, K. et al. The cell polarity protein ASIP/PAR-3 directly associates with junctional adhesion molecule (JAM). EMBO J. 20, 3738–3748 (2001).

    Article  CAS  Google Scholar 

  20. Takekuni, K. et al. Direct binding of cell polarity protein PAR-3 to cell–cell adhesion molecule nectin at neuroepithelial cells of developing mouse. J. Biol. Chem. 278, 5497–5500 (2003).

    Article  CAS  Google Scholar 

  21. Kovacs, M., Toth, J., Hetenyi, C., Malnasi-Csizmadia, A. & Sellers, J. R. Mechanism of blebbistatin inhibition of myosin II. J. Biol. Chem. 279, 35557–35563 (2004).

    Article  CAS  Google Scholar 

  22. Kosako, H. et al. Rho-kinase/ROCK is involved in cytokinesis through the phosphorylation of myosin light chain and not ezrin/radixin/moesin proteins at the cleavage furrow. Oncogene 19, 6059–6064 (2000).

    Article  CAS  Google Scholar 

  23. Totsukawa, G. et al. Distinct roles of ROCK (Rho-kinase) and MLCK in spatial regulation of MLC phosphorylation for assembly of stress fibres and focal adhesions in 3T3 fibroblasts. J. Cell Biol. 150, 797–806 (2000).

    Article  CAS  Google Scholar 

  24. Noren, N. K., Niessen, C. M., Gumbiner, B. M. & Burridge, K. Cadherin engagement regulates Rho family GTPases. J. Biol. Chem. 276, 33305–33308 (2001).

    Article  CAS  Google Scholar 

  25. Malliri, A., van Es, S., Huveneers, S. & Collard, J. G. The Rac exchange factor Tiam1 is required for the establishment and maintenance of cadherin-based adhesions. J. Biol. Chem. 279, 30092–30098 (2004).

    Article  CAS  Google Scholar 

  26. Stam, J. C. et al. Targeting of Tiam1 to the plasma membrane requires the cooperative function of the N-terminal pleckstrin homology domain and an adjacent protein interaction domain. J. Biol. Chem. 272, 28447–28454 (1997).

    Article  CAS  Google Scholar 

  27. Knoblich, J. A. Asymmetric cell division during animal development. Nature Rev. Mol. Cell Biol. 2, 11–20 (2001).

    Article  CAS  Google Scholar 

  28. Jan, Y. N. & Jan, L. Y. Asymmetric cell division in the Drosophila nervous system. Nature Rev. Neurosci. 2, 772–779 (2001).

    Article  CAS  Google Scholar 

  29. Brummelkamp, T. R., Bernards, R. & Agami, R. A system for stable expression of short interfering RNAs in mammalian cells. Science 296, 550–553 (2002).

    Article  CAS  Google Scholar 

  30. Ren, X. D. & Schwartz, M. A. Determination of GTP loading on Rho. Methods Enzymol. 325, 264–272 (2000).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank J. G. Collard for providing Tiam1 C1199 plasmid and anti-Tiam1 antibody, M. A. Schwartz for pGEX-RBD and pGEX-PBD plasmids, and A. Spang (Tübingen) and members of the Macara laboratory for helpful comments. This work was supported by grants GM070902 and CA40042 from the National Institutes of Health, DHHS.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Xinyu Chen.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Supplementary information

Supplementary figures S1, S2 and S3 (PDF 554 kb)

Rights and permissions

Reprints and permissions

About this article

Cite this article

Chen, X., Macara, I. Par-3 controls tight junction assembly through the Rac exchange factor Tiam1. Nat Cell Biol 7, 262–269 (2005). https://doi.org/10.1038/ncb1226

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ncb1226

This article is cited by

Search

Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing