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Structural basis of steroid hormone perception by the receptor kinase BRI1

Abstract

Polyhydroxylated steroids are regulators of body shape and size in higher organisms. In metazoans, intracellular receptors recognize these molecules. Plants, however, perceive steroids at membranes, using the membrane-integral receptor kinase BRASSINOSTEROID INSENSITIVE 1 (BRI1). Here we report the structure of the Arabidopsis thaliana BRI1 ligand-binding domain, determined by X-ray diffraction at 2.5 Å resolution. We find a superhelix of 25 twisted leucine-rich repeats (LRRs), an architecture that is strikingly different from the assembly of LRRs in animal Toll-like receptors. A 70-amino-acid island domain between LRRs 21 and 22 folds back into the interior of the superhelix to create a surface pocket for binding the plant hormone brassinolide. Known loss- and gain-of-function mutations map closely to the hormone-binding site. We propose that steroid binding to BRI1 generates a docking platform for a co-receptor that is required for receptor activation. Our findings provide insight into the activation mechanism of this highly expanded family of plant receptors that have essential roles in hormone, developmental and innate immunity signalling.

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Figure 1: The BRI1 ectodomain forms a superhelix.
Figure 2: Plant-specific sequence fingerprints cause the superhelical arrangement.
Figure 3: The steroid hormone binding site maps to the C-terminal inner surface of the superhelix.
Figure 4: An accessible membrane-proximal region of BRI1 may provide a protein–protein interaction platform.

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Accession codes

Primary accessions

Protein Data Bank

Data deposits

Atomic coordinates and structure factors for the reported crystal structures have been deposited in the Protein Data Bank under accession numbers 3RIZ for the unliganded BRI1 ectodomain and 3RJ0 for the BRI1–brassinolide complex.

References

  1. Shiu, S. H. & Bleecker, A. B. Receptor-like kinases from Arabidopsis form a monophyletic gene family related to animal receptor kinases. Proc. Natl Acad. Sci. USA 98, 10763–10768 (2001)

    Article  ADS  CAS  Google Scholar 

  2. Li, J. & Chory, J. A putative leucine-rich repeat receptor kinase involved in brassinosteroid signal transduction. Cell 90, 929–938 (1997)

    Article  CAS  Google Scholar 

  3. Clark, S. E., Williams, R. W. & Meyerowitz, E. M. The CLAVATA1 gene encodes a putative receptor kinase that controls shoot and floral meristem size in Arabidopsis . Cell 89, 575–585 (1997)

    Article  CAS  Google Scholar 

  4. Nadeau, J. A. & Sack, F. D. Control of stomatal distribution on the Arabidopsis leaf surface. Science 296, 1697–1700 (2002)

    Article  ADS  CAS  Google Scholar 

  5. Gómez-Gómez, L. & Boller, T. FLS2: an LRR receptor-like kinase involved in the perception of the bacterial elicitor flagellin in Arabidopsis . Mol. Cell 5, 1003–1011 (2000)

    Article  Google Scholar 

  6. Nishimura, R. et al. HAR1 mediates systemic regulation of symbiotic organ development. Nature 420, 426–429 (2002)

    Article  ADS  CAS  Google Scholar 

  7. Wang, Z. Y., Seto, H., Fujioka, S., Yoshida, S. & Chory, J. BRI1 is a critical component of a plasma-membrane receptor for plant steroids. Nature 410, 380–383 (2001)

    Article  ADS  CAS  Google Scholar 

  8. Ogawa, M., Shinohara, H., Sakagami, Y. & Matsubayashi, Y. Arabidopsis CLV3 peptide directly binds CLV1 ectodomain. Science 319, 294 (2008)

    Article  ADS  CAS  Google Scholar 

  9. Belkhadir, Y. & Chory, J. Brassinosteroid signaling: a paradigm for steroid hormone signaling from the cell surface. Science 314, 1410–1411 (2006)

    Article  ADS  CAS  Google Scholar 

  10. Vert, G., Nemhauser, J. L., Geldner, N., Hong, F. & Chory, J. Molecular mechanisms of steroid hormone signaling in plants. Annu. Rev. Cell Dev. Biol. 21, 177–201 (2005)

    Article  CAS  Google Scholar 

  11. Mangelsdorf, D. J. et al. The nuclear receptor superfamily: the second decade. Cell 83, 835–839 (1995)

    Article  CAS  Google Scholar 

  12. Geldner, N., Hyman, D. L., Wang, X., Schumacher, K. & Chory, J. Endosomal signaling of plant steroid receptor kinase BRI1. Genes Dev. 21, 1598–1602 (2007)

    Article  CAS  Google Scholar 

  13. Wang, X. et al. Autoregulation and homodimerization are involved in the activation of the plant steroid receptor BRI1. Dev. Cell 8, 855–865 (2005)

    Article  CAS  Google Scholar 

  14. Wang, X. & Chory, J. Brassinosteroids regulate dissociation of BKI1, a negative regulator of BRI1 signaling, from the plasma membrane. Science 313, 1118–1122 (2006)

    Article  ADS  CAS  Google Scholar 

  15. He, Z. et al. Perception of brassinosteroids by the extracellular domain of the receptor kinase BRI1. Science 288, 2360–2363 (2000)

    Article  ADS  CAS  Google Scholar 

  16. Kinoshita, T. et al. Binding of brassinosteroids to the extracellular domain of plant receptor kinase BRI1. Nature 433, 167–171 (2005)

    Article  ADS  CAS  Google Scholar 

  17. Wang, X. et al. Identification and functional analysis of in vivo phosphorylation sites of the Arabidopsis BRASSINOSTEROID-INSENSITIVE1 receptor kinase. Plant Cell 17, 1685–1703 (2005)

    Article  CAS  Google Scholar 

  18. Jaillais, Y. et al. Tyrosine phosphorylation controls brassinosteroid receptor activation by triggering membrane release of its kinase inhibitor. Genes Dev. 25, 232–237 (2011)

    Article  CAS  Google Scholar 

  19. Chinchilla, D., Shan, L., He, P., de Vries, S. & Kemmerling, B. One for all: the receptor-associated kinase BAK1. Trends Plant Sci. 14, 535–541 (2009)

    Article  CAS  Google Scholar 

  20. Nam, K. H. & Li, J. BRI1/BAK1, a receptor kinase pair mediating brassinosteroid signaling. Cell 110, 203–212 (2002)

    Article  CAS  Google Scholar 

  21. Li, J. et al. BAK1, an Arabidopsis LRR receptor-like protein kinase, interacts with BRI1 and modulates brassinosteroid signaling. Cell 110, 213–222 (2002)

    Article  CAS  Google Scholar 

  22. Wang, X. et al. Sequential transphosphorylation of the BRI1/BAK1 receptor kinase complex impacts early events in brassinosteroid signaling. Dev. Cell 15, 220–235 (2008)

    Article  CAS  Google Scholar 

  23. Kim, T.-W. & Wang, Z.-Y. Brassinosteroid signal transduction from receptor kinases to transcription factors. Annu. Rev. Plant Biol. 61, 681–704 (2010)

    Article  CAS  Google Scholar 

  24. Choe, J., Kelker, M. S. & Wilson, I. A. Crystal structure of human toll-like receptor 3 (TLR3) ectodomain. Science 309, 581–585 (2005)

    Article  ADS  CAS  Google Scholar 

  25. Liu, L. et al. Structural basis of toll-like receptor 3 signaling with double-stranded RNA. Science 320, 379–381 (2008)

    Article  ADS  CAS  Google Scholar 

  26. Park, B. S. et al. The structural basis of lipopolysaccharide recognition by the TLR4-MD-2 complex. Nature 458, 1191–1195 (2009)

    Article  ADS  CAS  Google Scholar 

  27. Bella, J., Hindle, K. L., McEwan, P. A. & Lovell, S. C. The leucine-rich repeat structure. Cell. Mol. Life Sci. 65, 2307–2333 (2008)

    Article  CAS  Google Scholar 

  28. Evdokimov, A. G., Anderson, D. E., Routzahn, K. M. & Waugh, D. S. Unusual molecular architecture of the Yersinia pestis cytotoxin YopM: a leucine-rich repeat protein with the shortest repeating unit. J. Mol. Biol. 312, 807–821 (2001)

    Article  CAS  Google Scholar 

  29. Schubert, W. D. et al. Structure of internalin, a major invasion protein of Listeria monocytogenes, in complex with its human receptor E-cadherin. Cell 111, 825–836 (2002)

    Article  CAS  Google Scholar 

  30. Di Matteo, A. et al. The crystal structure of polygalacturonase-inhibiting protein (PGIP), a leucine-rich repeat protein involved in plant defense. Proc. Natl Acad. Sci. USA 100, 10124–10128 (2003)

    Article  ADS  CAS  Google Scholar 

  31. Kajava, A. V. Structural diversity of leucine-rich repeat proteins. J. Mol. Biol. 277, 519–527 (1998)

    Article  CAS  Google Scholar 

  32. Noguchi, T. et al. Brassinosteroid-insensitive dwarf mutants of Arabidopsis accumulate brassinosteroids. Plant Physiol. 121, 743–752 (1999)

    Article  CAS  Google Scholar 

  33. Jin, H., Yan, Z., Nam, K. H. & Li, J. Allele-specific suppression of a defective brassinosteroid receptor reveals a physiological role of UGGT in ER quality control. Mol. Cell 26, 821–830 (2007)

    Article  CAS  Google Scholar 

  34. Fujioka, S. et al. The Arabidopsis deetiolated2 mutant is blocked early in brassinosteroid biosynthesis. Plant Cell 9, 1951–1962 (1997)

    Article  CAS  Google Scholar 

  35. Back, T. G. & Pharis, R. P. Structure-activity studies of brassinosteroids and the search for novel analogues and mimetics with improved bioactivity. J. Plant Growth Regul. 22, 350–361 (2003)

    Article  CAS  Google Scholar 

  36. Diévart, A., Hymes, M. J., Li, J. & Clark, S. E. Brassinosteroid-independent function of BRI1/CLV1 chimeric receptors. Funct. Plant Biol. 33, 723–730 (2006)

    Article  Google Scholar 

  37. Gruszka, D., Szarejko, I. & Maluszynski, M. New allele of HvBRI1 gene encoding brassinosteroid receptor in barley. J. Appl. Genet. (published online, 10.1007/s13353-011-0031-7 8 February 2011)

    Google Scholar 

  38. Friedrichsen, D. M., Joazeiro, C. A., Li, J., Hunter, T. & Chory, J. Brassinosteroid-insensitive-1 is a ubiquitously expressed leucine-rich repeat receptor serine/threonine kinase. Plant Physiol. 123, 1247–1256 (2000)

    Article  CAS  Google Scholar 

  39. Hink, M. A., Shah, K., Russinova, E., de Vries, S. C. & Visser, A. J. W. G. Fluorescence fluctuation analysis of Arabidopsis thaliana somatic embryogenesis receptor-like kinase and brassinosteroid insensitive 1 receptor oligomerization. Biophys. J. 94, 1052–1062 (2008)

    Article  CAS  Google Scholar 

  40. Russinova, E. et al. Heterodimerization and endocytosis of Arabidopsis brassinosteroid receptors BRI1 and AtSERK3 (BAK1). Plant Cell 16, 3216–3229 (2004)

    Article  CAS  Google Scholar 

  41. Han, B. W., Herrin, B. R., Cooper, M. D. & Wilson, I. A. Antigen recognition by variable lymphocyte receptors. Science 321, 1834–1837 (2008)

    Article  ADS  CAS  Google Scholar 

  42. Whippo, C. W. & Hangarter, R. P. A brassinosteroid-hypersensitive mutant of BAK1 indicates that a convergence of photomorphogenic and hormonal signaling modulates phototropism. Plant Physiol. 139, 448–457 (2005)

    Article  CAS  Google Scholar 

  43. He, K. et al. BAK1 and BKK1 regulate brassinosteroid-dependent growth and brassinosteroid-independent cell-death pathways. Curr. Biol. 17, 1109–1115 (2007)

    Article  CAS  Google Scholar 

  44. Karlova, R. et al. The Arabidopsis SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE1 protein complex includes BRASSINOSTEROID-INSENSITIVE1. Plant Cell 18, 626–638 (2006)

    Article  CAS  Google Scholar 

  45. Kabsch, W. Automatic processing of rotation diffraction data from crystals of initially unknown symmetry and cell constants. J. Appl. Crystallogr. 26, 795–800 (1993)

    Article  CAS  Google Scholar 

  46. Sheldrick, G. M. A short history of SHELX. Acta Crystallogr. A 64, 112–122 (2008)

    Article  ADS  CAS  Google Scholar 

  47. Bricogne, G., Vonrhein, C., Flensburg, C., Schiltz, M. & Paciorek, W. Generation, representation and flow of phase information in structure determination: recent developments in and around SHARP 2.0. Acta Crystallogr. D 59, 2023–2030 (2003)

    Article  CAS  Google Scholar 

  48. Terwilliger, T. C. et al. Iterative model building, structure refinement and density modification with the PHENIX AutoBuild wizard. Acta Crystallogr. D 64, 61–69 (2008)

    Article  CAS  Google Scholar 

  49. Emsley, P. & Cowtan, K. Coot: model-building tools for molecular graphics. Acta Crystallogr. D 60, 2126–2132 (2004)

    Article  Google Scholar 

  50. Davis, I. W. et al. MolProbity: all-atom contacts and structure validation for proteins and nucleic acids. Nucleic Acids Res. 35, W375–W383 (2007)

    Article  ADS  Google Scholar 

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Acknowledgements

We thank J. Vanhnasy and W. Yu for maintaining insect cell stocks, M. Jinek and B. W. Han for advice, W. Kwiatowski for maintenance of the Salk X-ray equipment, Y. Jaillais for discussion, and F. V. Chisari for encouragement and support. This work was supported by the Howard Hughes Medical Institute and a grant from the National Science Foundation (IOS-0649389) to J.C. M.H. was supported by long-term fellowships from the European Molecular Biology Organisation and the International Human Frontier Science Program Organisation. Y.B. was a Howard Hughes Medical Institute fellow of the Life Sciences Research Foundation and also received support from the Philippe Foundation. I.A.W. was supported by NIH grant AI042266 and by the Skaggs Institute for Chemical Biology.

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M.H., Y.B., J.P.N. and J.C. designed the project. M.H. expressed the BRI1 ectodomain in the laboratory of I.A.W. with initial help from Y.B. M.H. purified and crystallized the protein, and phased and refined the structures. M.D. determined viral titres and optimized production of viruses. T.D. cloned the modified transfer vector. M.H., I.A.W. and J.C. analysed the data. J.C. supervised the project. M.H. wrote the paper with input from the other authors.

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Correspondence to Joanne Chory.

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Hothorn, M., Belkhadir, Y., Dreux, M. et al. Structural basis of steroid hormone perception by the receptor kinase BRI1. Nature 474, 467–471 (2011). https://doi.org/10.1038/nature10153

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