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:

X-linked and cellular IAPs modulate the stability of C-RAF kinase and cell motility

An Erratum to this article was published on 01 January 2009

This article has been updated

Abstract

Inhibitor of apoptosis proteins (IAP) are evolutionarily conserved anti-apoptotic regulators1,2. C-RAF protein kinase is a direct RAS effector protein, which initiates the classical mitogen-activated protein kinase (MAPK) cascade. This signalling cascade mediates diverse biological functions, such as cell growth, proliferation, migration, differentiation and survival3,4. Here we demonstrate that XIAP and c-IAPs bind directly to C-RAF kinase and that siRNA-mediated silencing of XIAP and c-IAPs leads to stabilization of C-RAF in human cells. XIAP binds strongly to C-RAF and promotes the ubiquitylation of C-RAF in vivo through the Hsp90-mediated quality control system, independently of its E3 ligase activity. In addition, XIAP or c-IAP-1/2 knockdown cells showed enhanced cell migration in a C-RAF-dependent manner. XIAP promotes binding of CHIP (carboxy terminal Hsc70-interacting protein), a chaperone-associated ubiquitin ligase, to the C-RAF–Hsp90 complex in vivo. Interfering with CHIP expression resulted in stabilization of C-RAF and enhanced cell migration, as observed in XIAP knockdown cells. Our data show an unexpected role of XIAP and c-IAPs in the turnover of C-RAF protein, thereby modulating the MAPK signalling pathway and cell migration.

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

Access options

Rent or buy this article

Prices vary by article type

from$1.95

to$39.95

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

Figure 1: XIAP and c-IAPs interact with C-RAF.
Figure 2: XIAP and c-IAPs modulate C-RAF stability.
Figure 3: XIAP and c-IAPs modulate cell motility in a C-RAF dependent manner.
Figure 4: XIAP modulates RAF stability through an Hsp90 quality control system.
Figure 5: Silencing CHIP expression stabilizes C-RAF and enhances cell migration.

Similar content being viewed by others

Change history

  • 24 November 2008

    In the version of this article initially published online, the label c-IAP-1 in Figure 1d was duplicated for both of the lower lines. The omitted c-IAP-2 label has been replaced in the HTML and PDF versions of the article.

References

  1. Eckelman, B. P., Salvesen, G. S., & Scott, F. L. Human inhibitor of apoptosis proteins: why XIAP is the black sheep of the family. EMBO Rep. 7, 988–994 (2006).

    Article  CAS  Google Scholar 

  2. Salvesen, G. S. & Duckett, C. S. IAP proteins: blocking the road to death's door. Nature Rev. Mol. Cell Biol. 3, 401–410 (2002).

    Article  CAS  Google Scholar 

  3. Rajalingam, K., Schreck, R., Rapp, U. R., & Albert, S. Ras oncogenes and their downstream targets. Biochim. Biophys. Acta 1773, 1177–1195 (2007).

    Article  CAS  Google Scholar 

  4. Wellbrock, C., Karasarides, M., & Marais, R. The RAF proteins take centre stage. Nature Rev. Mol. Cell Biol. 5, 875–885 (2004).

    Article  CAS  Google Scholar 

  5. Srinivasula, S. M. & Ashwell, J. D. IAPs: What's in a name? Mol. Cell 30, 123–135 (2008).

    Article  CAS  Google Scholar 

  6. Wright, C. W. & Duckett, C. S. Reawakening the cellular death program in neoplasia through the therapeutic blockade of IAP function. J. Clin. Invest. 115, 2673–2678 (2005).

    Article  CAS  Google Scholar 

  7. Vaux, D. L. & Silke, J. IAPs, RINGs and ubiquitylation. Nature Rev. Mol. Cell Biol. 6, 287–297 (2005).

    Article  CAS  Google Scholar 

  8. Burstein, E. et al. A novel role for XIAP in copper homeostasis through regulation of MURR1. EMBO J. 23, 244–254 (2004).

    Article  CAS  Google Scholar 

  9. Olayioye, M. A. et al. XIAP-deficiency leads to delayed lobuloalveolar development in the mammary gland. Cell Death Differ. 12, 87–90 (2004).

    Article  Google Scholar 

  10. Alavi, A., Hood, J. D., Frausto, R., Stupack, D. G., & Cheresh, D. A. Role of Raf in vascular protection from distinct apoptotic stimuli. Science 301, 94–96 (2003).

    Article  CAS  Google Scholar 

  11. Dhillon, A. S., Hagan, S., Rath, O., & Kolch, W. MAP kinase signalling pathways in cancer. Oncogene 26, 3279–3290 (2007).

    Article  CAS  Google Scholar 

  12. Rapp, U. R., Rennefahrt, U., & Troppmair, J. Bcl-2 proteins: master switches at the intersection of death signaling and the survival control by Raf kinases. Biochim. Biophys. Acta 1644, 149–158 (2004).

    Article  CAS  Google Scholar 

  13. Tian, S. et al. Interaction and stabilization of X-linked inhibitor of apoptosis by Raf-1 protein kinase. Int. J. Oncol. 29, 861–867 (2006).

    CAS  PubMed  Google Scholar 

  14. Klemke, R. L. et al. Regulation of cell motility by mitogen-activated protein kinase. J. Cell Biol. 137, 481–492 (1997).

    Article  CAS  Google Scholar 

  15. Rajalingam, K. et al. Prohibitin is required for Ras-induced Raf–MEK–ERK activation and epithelial cell migration. Nature Cell Biol. 7, 837–843 (2005).

    Article  CAS  Google Scholar 

  16. Srinivasula, S. M. et al. A conserved XIAP-interaction motif in caspase-9 and Smac/DIABLO regulates caspase activity and apoptosis. Nature 410, 112–116 (2001).

    Article  CAS  Google Scholar 

  17. Vucic, D. Targeting IAP (inhibitor of apoptosis) proteins for therapeutic intervention in tumors. Curr. Cancer Drug Targets 8, 110–117 (2008).

    Article  CAS  Google Scholar 

  18. da Rocha, D. S. et al. Activated B-RAF is an Hsp90 client protein that is targeted by the anticancer drug 17-allylamino-17-demethoxygeldanamycin. Cancer Res. 65, 10686–10691 (2005).

    Article  Google Scholar 

  19. Grbovic, O. M. et al. V600E B-Raf requires the Hsp90 chaperone for stability and is degraded in response to Hsp90 inhibitors. Proc. Natl Acad. Sci. USA 103, 57–62 (2006).

    Article  CAS  Google Scholar 

  20. McDonough, H. & Patterson, C. CHIP: a link between the chaperone and proteasome systems. Cell Stress Chaperones 8, 303–308 (2003).

    Article  CAS  Google Scholar 

  21. Arndt, V., Rogon, C., & Hohfeld, J. To be, or not to be — molecular chaperones in protein degradation. Cell Mol. Life Sci. 64, 2525–2541 (2007).

    Article  CAS  Google Scholar 

  22. Isaacs, J. S., Xu, W., & Neckers, L. Heat shock protein 90 as a molecular target for cancer therapeutics. Cancer Cell 3, 213–217 (2003).

    Article  CAS  Google Scholar 

  23. Schulte, T. W. et al. Destabilization of Raf-1 by geldanamycin leads to disruption of the Raf–1–MEK-mitogen-activated protein kinase signalling pathway. Mol. Cell Biol. 16, 5839–5845 (1996).

    Article  CAS  Google Scholar 

  24. Schulte, T. W., An, W. G., & Neckers, L. M. Geldanamycin-induced destabilization of Raf-1 involves the proteasome. Biochem. Biophys. Res. Commun. 239, 655–659 (1997).

    Article  CAS  Google Scholar 

  25. Schneider, C. et al. Pharmacologic shifting of a balance between protein refolding and degradation mediated by Hsp90. Proc. Natl Acad. Sci. USA 93, 14536–14541 (1996).

    Article  CAS  Google Scholar 

  26. Young, J. C., Agashe, V. R., Siegers, K., & Hartl, F. U. Pathways of chaperone-mediated protein folding in the cytosol. Nature Rev. Mol. Cell Biol. 5, 781–791 (2004).

    Article  CAS  Google Scholar 

  27. Demand, J., Alberti, S., Patterson, C., & Hohfeld, J. Cooperation of a ubiquitin domain protein and an E3 ubiquitin ligase during chaperone/proteasome coupling. Curr. Biol. 11, 1569–1577 (2001).

    Article  CAS  Google Scholar 

  28. Noble, C. et al. CRAF autophosphorylation of serine 621 is required to prevent its proteasome-mediated degradation. Mol. Cell 31, 862–872 (2008).

    Article  CAS  Google Scholar 

  29. Harlin, H., Reffey, S. B., Duckett, C. S., Lindsten, T., & Thompson, C. B. Characterization of XIAP-deficient mice. Mol. Cell Biol. 21, 3604–3608 (2001).

    Article  CAS  Google Scholar 

  30. Rajalingam, K. et al. IAP–IAP complexes required for apoptosis resistance of C. trachomatis-infected cells. PLoS Pathog. 2, e114 (2006).

    Article  Google Scholar 

  31. Downward, J. Targeting RAS signalling pathways in cancer therapy. Nature Rev. Cancer 3, 11–22 (2003).

    Article  CAS  Google Scholar 

Download references

Acknowledgements

We thank Pascal Meier, Richard Marais, Len Neckers, Yuri Lazebnik and H.Wayant for valuable reagents; Brigitte Ruester and Reinhard Henschler for assistance with cell sorting; Renate Metz for help with the purification of proteins; Andreas Fischer for Biacore analysis; Juliane Mooz and Barbara Bauer for technical assistance. This work is supported by an Emmy Noether programme grant (RA1739/1–1) to K.R. from the DFG and various grants to U.R.R. from DFG, including Immunomodulation and German-French Graduate Schools, SFB487, SFB581, and grants from the Scheel Stiftung. E.S.A. is supported by grants from the NIH (GMO76167). We thank Antoine Galmiche for sharing unpublished observations, Ralf Schreck and Ritva Tikkanen for critically reading the manuscript.

Author information

Authors and Affiliations

Authors

Contributions

T.D. performed most of the experiments; T.K.O. performed additional experiments; G.S.H. performed the microscopic analyses; C.K. wrote the algorithms and performed the quantification of transwell migration experiments; M.H. performed the BIAcore measurements; E.S.A. provided valuable materials and advice; U.R.R. initiated the project, provided valuable materials and critical advice; K.R. conceived and designed the experiments, analysed and interpreted data with all authors, coordinated the study and wrote the paper.

Corresponding author

Correspondence to Krishnaraj Rajalingam.

Ethics declarations

Competing interests

The authors declare no competing financial interests.

Supplementary information

Rights and permissions

Reprints and permissions

About this article

Cite this article

Dogan, T., Harms, G., Hekman, M. et al. X-linked and cellular IAPs modulate the stability of C-RAF kinase and cell motility. Nat Cell Biol 10, 1447–1455 (2008). https://doi.org/10.1038/ncb1804

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1038/ncb1804

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