Skip to main content

Thank you for visiting 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.

Inhibition of cytohesins by SecinH3 leads to hepatic insulin resistance


G proteins are an important class of regulatory switches in all living systems. They are activated by guanine nucleotide exchange factors (GEFs), which facilitate the exchange of GDP for GTP1,2. This activity makes GEFs attractive targets for modulating disease-relevant G-protein-controlled signalling networks3,4,5. GEF inhibitors are therefore of interest as tools for elucidating the function of these proteins and for therapeutic intervention; however, only one small molecule GEF inhibitor, brefeldin A (BFA), is currently available6,7,8,9. Here we used an aptamer displacement screen to identify SecinH3, a small molecule antagonist of cytohesins. The cytohesins are a class of BFA-resistant small GEFs for ADP-ribosylation factors (ARFs), which regulate cytoskeletal organization10, integrin activation11 or integrin signalling12. The application of SecinH3 in human liver cells showed that insulin-receptor-complex-associated cytohesins are required for insulin signalling. SecinH3-treated mice show increased expression of gluconeogenic genes, reduced expression of glycolytic, fatty acid and ketone body metabolism genes in the liver, reduced liver glycogen stores, and a compensatory increase in plasma insulin. Thus, cytohesin inhibition results in hepatic insulin resistance. Because insulin resistance is among the earliest pathological changes in type 2 diabetes, our results show the potential of chemical biology for dissecting the molecular pathogenesis of this disease.

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

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Prices vary by article type



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

Figure 1: Structure and characterization of SecinH3.
Figure 2: SecinH3 inhibits insulin signalling in HepG2 cells.
Figure 3: Impaired cytohesin function results in hepatic insulin resistance.


  1. Cherfils, J. & Chardin, P. GEFs: structural basis for their activation of small GTP-binding proteins. Trends Biochem. Sci. 24, 306–311 (1999)

    Article  CAS  Google Scholar 

  2. Jackson, C. L. & Casanova, J. E. Turning on ARF: the Sec7 family of guanine-nucleotide-exchange factors. Trends Cell Biol. 10, 60–67 (2000)

    Article  CAS  Google Scholar 

  3. Hashimoto, S. et al. Requirement for Arf6 in breast cancer invasive activities. Proc. Natl Acad. Sci. USA 101, 6647–6652 (2004)

    Article  ADS  CAS  Google Scholar 

  4. Gonzalez-Garcia, A. et al. RalGDS is required for tumor formation in a model of skin carcinogenesis. Cancer Cell 7, 219–226 (2005)

    Article  CAS  Google Scholar 

  5. Malliri, A. et al. Mice deficient in the Rac activator Tiam1 are resistant to Ras-induced skin tumours. Nature 417, 867–871 (2002)

    Article  ADS  CAS  Google Scholar 

  6. Donaldson, J. G., Finazzi, D. & Klausner, R. D. Brefeldin A inhibits Golgi membrane-catalysed exchange of guanine nucleotide onto ARF protein. Nature 360, 350–352 (1992)

    Article  ADS  CAS  Google Scholar 

  7. Helms, J. B. & Rothman, J. E. Inhibition by brefeldin A of a Golgi membrane enzyme that catalyses exchange of guanine nucleotide bound to ARF. Nature 360, 352–354 (1992)

    Article  ADS  CAS  Google Scholar 

  8. Morinaga, N., Tsai, S.-C., Moss, J. & Vaughan, M. Isolation of a brefeldin A-inhibited guanine nucleotide-exchange protein for ADP ribosylation factor (ARF) 1 and ARF3 that contains a Sec7-like domain. Proc. Natl Acad. Sci. USA 93, 12856–12860 (1996)

    Article  ADS  CAS  Google Scholar 

  9. Peyroche, A. et al. Brefeldin A acts to stabilize an abortive ARF–GDP–Sec7 domain protein complex: involvement of specific residues of the Sec7 domain. Mol. Cell. Biol. 3, 275–285 (1999)

    CAS  Google Scholar 

  10. Mayer, G. et al. Controlling small guanine-nucleotide-exchange factor function through cytoplasmic RNA intramers. Proc. Natl Acad. Sci. USA 98, 4961–4965 (2001)

    Article  ADS  CAS  Google Scholar 

  11. Kolanus, W. et al. αLβ2 integrin/LFA-1 binding to ICAM-1 induced by cytohesin-1, a cytoplasmic regulatory molecule. Cell 86, 233–242 (1996)

    Article  CAS  Google Scholar 

  12. Perez, O. D. et al. Leukocyte functional antigen 1 lowers T cell activation thresholds and signaling through cytohesin-1 and Jun-activating binding protein 1. Nature Immunol. 4, 1083–1092 (2003)

    Article  ADS  CAS  Google Scholar 

  13. Renault, L., Guibert, B. & Cherfils, J. Structural snapshots of the mechanism and inhibition of a guanine nucleotide exchange factor. Nature 426, 525–530 (2003)

    Article  ADS  CAS  Google Scholar 

  14. Mossessova, E., Corpina, R. A. & Goldberg, J. Crystal structure of ARF1*Sec7 complexed with Brefeldin A and its implications for the guanine nucleotide exchange mechanism. Mol. Cell 12, 1403–1411 (2003)

    Article  CAS  Google Scholar 

  15. Kruljac-Letunic, A., Moelleken, J., Kallin, A., Wieland, F. & Blaukat, A. The tyrosine kinase Pyk2 regulates Arf1 activity by phosphorylation and inhibition of the Arf-GTPase-activating protein ASAP1. J. Biol. Chem. 278, 29560–29570 (2003)

    Article  CAS  Google Scholar 

  16. Ahmadian, M. R., Wittinghofer, A. & Herrmann, C. Fluorescence methods in the study of small GTP-binding proteins. Methods Mol. Biol. 189, 45–63 (2002)

    CAS  PubMed  Google Scholar 

  17. Moss, J. & Vaughan, M. Molecules in the ARF Orbit. J. Biol. Chem. 273, 21431–21434 (1998)

    Article  CAS  Google Scholar 

  18. Fuss, B., Becker, T., Zinke, I. & Hoch, M. The cytohesin Steppke is essential for insulin signalling in Drosophila. Nature doi:10.1038/nature05412 (this issue).

  19. Takatsu, H., Yoshino, K., Toda, K. & Nakayama, K. GGA proteins associate with Golgi membranes through interaction between their GGAH domains and ADP-ribosylation factors. Biochem. J. 365, 369–378 (2002)

    Article  CAS  Google Scholar 

  20. Brunet, A. et al. Akt promotes cell survival by phosphorylating and inhibiting a Forkhead transcription factor. Cell 96, 857–868 (1999)

    Article  CAS  Google Scholar 

  21. Kops, G. J. et al. Direct control of the Forkhead transcription factor AFX by protein kinase B. Nature 398, 630–634 (1999)

    Article  ADS  CAS  Google Scholar 

  22. Burgering, B. M. & Kops, G. J. Cell cycle and death control: long live Forkheads. Trends Biochem. Sci. 27, 352–360 (2002)

    Article  CAS  Google Scholar 

  23. Accili, D. & Arden, K. C. FoxOs at the crossroads of cellular metabolism, differentiation, and transformation. Cell 117, 421–426 (2004)

    Article  CAS  Google Scholar 

  24. Knight, Z. A. et al. A pharmacological map of the PI3-K family defines a role for p110α in insulin signaling. Cell 125, 733–747 (2006)

    Article  CAS  Google Scholar 

  25. Michael, M. D. et al. Loss of insulin signaling in hepatocytes leads to severe insulin resistance and progressive hepatic dysfunction. Mol. Cell 6, 87–97 (2000)

    Article  CAS  Google Scholar 

  26. Biddinger, S. B. & Kahn, C. R. From mice to men: insights into the insulin resistance syndromes. Annu. Rev. Physiol. 68, 123–158 (2006)

    Article  CAS  Google Scholar 

  27. Kubota, N. et al. Disruption of insulin receptor substrate 2 causes type 2 diabetes because of liver insulin resistance and lack of compensatory beta-cell hyperplasia. Diabetes 49, 1880–1889 (2000)

    Article  CAS  Google Scholar 

  28. Withers, D. J. et al. Disruption of IRS-2 causes type 2 diabetes in mice. Nature 391, 900–904 (1998)

    Article  ADS  CAS  Google Scholar 

  29. Nakae, J. et al. Regulation of insulin action and pancreatic beta-cell function by mutated alleles of the gene encoding forkhead transcription factor Foxo1. Nature Genet. 32, 245–253 (2002)

    Article  CAS  Google Scholar 

  30. Malecki, M. T. Genetics of type 2 diabetes mellitus. Diabetes Res. Clin. Pract. 68, S10–S21 (2005)

    Article  CAS  Google Scholar 

  31. Mora, A., Lipina, C., Tronche, F., Sutherland, C. & Alessi, D. R. Deficiency of PDK1 in liver results in glucose intolerance, impairment of insulin-regulated gene expression and liver failure. Biochem. J. 385, 639–648 (2005)

    Article  CAS  Google Scholar 

Download references


We thank M. Franco for ARF6 and EFA6 plasmids, R. Quirion for the EGFP–FoxO1A plasmid, J. Kuriyan for the Ras and Sos plasmids, J.-L. Parent for the GST–GGA3 plasmid, M. Hoch for the steppke plasmid, V. Fieberg, K. Rotscheidt, N. Kuhn, R. Tolba, and A. Carney for technical assistance and the members of the Famulok laboratory for helpful discussions. This work was supported by grants from the Deutsche Forschungsgemeinschaft, the Sonderforschungsbereiche 645 and 704, the Fonds der Chemischen Industrie (to M.F.), and the Alexander von Humboldt foundation (to S.G.S.). Author Contributions M. H. and A.S. contributed equally to this work. M.H. and A.S. performed and designed, with M.F., most of the included studies. I.G. performed the aptamer displacement screen and binding and in vitro inhibition analyses of Secins. S.G.S. synthesized all Secin derivatives. W.K. provided cytohesin and ARF expression plasmids, E.K. produced the cyh3 monoclonal antibody and B.P. characterized it. T.Q. performed the analysis of Golgi integrity and ARF6 membrane recruitment. I.B. and A.S. did the immunoprecipitation experiments. M.F. supervised the research project, and assisted in the experimental design. All authors discussed the experimental results. A.S. and M.F. wrote the manuscript.

Author information

Authors and Affiliations


Corresponding author

Correspondence to Michael Famulok.

Ethics declarations

Competing interests

Reprints and permissions information is available at The authors declare no competing financial interests.

Supplementary information

Supplementary Information

This file contains complete Supplementary Information including Supplementary Methods, Supplementary Figures 1-14 and Supplementary Tables (PDF 1079 kb)

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Hafner, M., Schmitz, A., Grüne, I. et al. Inhibition of cytohesins by SecinH3 leads to hepatic insulin resistance. Nature 444, 941–944 (2006).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


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