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Structure-function analyses of the human SIX1–EYA2 complex reveal insights into metastasis and BOR syndrome

Nature Structural & Molecular Biology volume 20, pages 447–453 (2013)Cite this article

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Abstract

SIX1 interacts with EYA to form a bipartite transcription factor essential for mammalian development. Loss of function of this complex causes branchio-oto-renal (BOR) syndrome, whereas re-expression of SIX1 or EYA promotes metastasis. Here we describe the 2.0-Å structure of SIX1 bound to EYA2, which suggests a new DNA-binding mechanism for SIX1 and provides a rationale for the effect of BOR syndrome mutations. The structure also reveals that SIX1 uses predominantly a single helix to interact with EYA. Substitution of a single amino acid in this helix is sufficient to disrupt SIX1-EYA interaction, SIX1-mediated epithelial-mesenchymal transition and metastasis in mouse models. Given that SIX1 and EYA are overexpressed in many tumor types, our data indicate that targeting the SIX1–EYA complex may be a potent approach to inhibit tumor progression in multiple cancer types.

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Figure 1: Structure of the MBP-SIX1–EYA2ED complex supports a new DNA-binding mechanism for SIX1.
Figure 2: Interacting surfaces of human SIX1 and EYA2ED.
Figure 3: Mapping BOR mutations on EYA2ED and SIX1.
Figure 4: Disruption of the SIX1–EYA transcriptional complex inhibits SIX1-mediated TGF-β signaling and characteristics of EMT.
Figure 5: Disruption of the SIX1–EYA transcriptional complex inhibits SIX1-mediated metastasis.

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Acknowledgements

The authors would like to thank M. Churchill, D. Micalizzi and W. Lilyestrom for critical reading of the manuscript as well as members of the Ford and Zhao laboratories for their help and suggestions. We would like to thank the University of Colorado AMC Biomolecular X-ray Crystallography Core; the Biostatistics and Bioinformatics Shared Resource of The University of Colorado Comprehensive Cancer Center (P30CA046934) for access to databases through Oncomine; the Advanced Light Source beam line 4.2.2 at Berkeley and J. Nix for help with earlier data collection. This work was supported by grants from the US National Cancer Institute (2R01-CA095277 and R01CA157790) to H.L.F. and from the US Department of Defense Synergistic IDEA award (W81XWH-09-1-0253), Breast Cancer Research Foundation–American Association for Cancer Research, State of Colorado (2009 and 2011) and US National Institutes of Health (R03DA030559 and R03DA033174) to H.L.F. and R.Z. A.N.P. was supported by a Pediatric Hematology/Oncology Postdoctoral Fellowship (2T32082086-11A1). Data in this paper were collected at Argonne National Laboratory, Structural Biology Center at the Advanced Photon Source operated by University of Chicago Argonne, LLC, for the US Department of Energy, Office of Biological and Environmental Research, under contract DE-AC02-06CH11357.

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Authors and Affiliations

  1. Department of Obstetrics and Gynecology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA

    Aaron N Patrick, Joshua H Cabrera, Anna L Smith & Heide L Ford

  2. Department of Biochemistry and Molecular Genetics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA

    Aaron N Patrick, Heide L Ford & Rui Zhao

  3. Department of Pharmacology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA

    Aaron N Patrick, Joshua H Cabrera, Anna L Smith & Heide L Ford

  4. Department of Molecular and Computational Biology, University of Southern California, Los Angeles, Los Angeles, California, USA.,

    Xiaojiang S Chen

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Contributions

A.N.P. performed the structural and biochemical experiments. J.H.C. performed the cell culture and animal experiments. A.L.S. performed the bioinformatic analyses. R.Z. and X.S.C. designed and supervised the structural and biochemical experiments. H.L.F. designed and supervised the cell culture and animal experiments. A.N.P., R.Z. and H.L.F. designed and conceived of the overall experimental design throughout the manuscript and together wrote the manuscript. All authors participated in the preparation of the manuscript.

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Correspondence to Heide L Ford or Rui Zhao.

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Patrick, A., Cabrera, J., Smith, A. et al. Structure-function analyses of the human SIX1–EYA2 complex reveal insights into metastasis and BOR syndrome. Nat Struct Mol Biol 20, 447–453 (2013). https://doi.org/10.1038/nsmb.2505

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