| Structural highlights
Function
[BRI1_ARATH] Receptor with a dual specificity kinase activity acting on both serine/threonine- and tyrosine-containing substrates. Regulates, in response to brassinosteroid binding, a signaling cascade involved in plant development, including expression of light- and stress-regulated genes, promotion of cell elongation, normal leaf and chloroplast senescence, and flowering. Binds brassinolide, and less effectively castasterone, but not 2,3,22,23-O-tetramethylbrassinolide or ecdysone. May be involved in a feedback regulation of brassinosteroid biosynthesis. Phosphorylates BRI1-associated receptor kinase 1 (BAK1), Transthyretin-Like protein (TTL) and SERK1 on 'Ser-299' and 'Thr-462' in vitro. May have a guanylyl cyclase activity.[1] [2] [3] [4] [5] [6]
Publication Abstract from PubMed
Brassinosteroids are essential phytohormones that have crucial roles in plant growth and development. Perception of brassinosteroids requires an active complex of BRASSINOSTEROID-INSENSITIVE 1 (BRI1) and BRI1-ASSOCIATED KINASE 1 (BAK1). Recognized by the extracellular leucine-rich repeat (LRR) domain of BRI1, brassinosteroids induce a phosphorylation-mediated cascade to regulate gene expression. Here we present the crystal structures of BRI1(LRR) in free and brassinolide-bound forms. BRI1(LRR) exists as a monomer in crystals and solution independent of brassinolide. It comprises a helical solenoid structure that accommodates a separate insertion domain at its concave surface. Sandwiched between them, brassinolide binds to a hydrophobicity-dominating surface groove on BRI1(LRR). Brassinolide recognition by BRI1(LRR) is through an induced-fit mechanism involving stabilization of two interdomain loops that creates a pronounced non-polar surface groove for the hormone binding. Together, our results define the molecular mechanisms by which BRI1 recognizes brassinosteroids and provide insight into brassinosteroid-induced BRI1 activation.
Structural insight into brassinosteroid perception by BRI1.,She J, Han Z, Kim TW, Wang J, Cheng W, Chang J, Shi S, Wang J, Yang M, Wang ZY, Chai J Nature. 2011 Jun 12;474(7352):472-6. doi: 10.1038/nature10178. PMID:21666666[7]
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.
References
- ↑ Noguchi T, Fujioka S, Choe S, Takatsuto S, Yoshida S, Yuan H, Feldmann KA, Tax FE. Brassinosteroid-insensitive dwarf mutants of Arabidopsis accumulate brassinosteroids. Plant Physiol. 1999 Nov;121(3):743-52. PMID:10557222
- ↑ Friedrichsen DM, Joazeiro CA, Li J, Hunter T, Chory J. Brassinosteroid-insensitive-1 is a ubiquitously expressed leucine-rich repeat receptor serine/threonine kinase. Plant Physiol. 2000 Aug;123(4):1247-56. PMID:10938344
- ↑ Belkhadir Y, Chory J. Brassinosteroid signaling: a paradigm for steroid hormone signaling from the cell surface. Science. 2006 Dec 1;314(5804):1410-1. PMID:17138891 doi:http://dx.doi.org/10.1126/science.1134040
- ↑ Kwezi L, Meier S, Mungur L, Ruzvidzo O, Irving H, Gehring C. The Arabidopsis thaliana brassinosteroid receptor (AtBRI1) contains a domain that functions as a guanylyl cyclase in vitro. PLoS One. 2007 May 23;2(5):e449. PMID:17520012 doi:http://dx.doi.org/10.1371/journal.pone.0000449
- ↑ Wang X, Kota U, He K, Blackburn K, Li J, Goshe MB, Huber SC, Clouse SD. Sequential transphosphorylation of the BRI1/BAK1 receptor kinase complex impacts early events in brassinosteroid signaling. Dev Cell. 2008 Aug;15(2):220-35. doi: 10.1016/j.devcel.2008.06.011. PMID:18694562 doi:10.1016/j.devcel.2008.06.011
- ↑ Oh MH, Wang X, Kota U, Goshe MB, Clouse SD, Huber SC. Tyrosine phosphorylation of the BRI1 receptor kinase emerges as a component of brassinosteroid signaling in Arabidopsis. Proc Natl Acad Sci U S A. 2009 Jan 13;106(2):658-63. Epub 2009 Jan 5. PMID:19124768 doi:0810249106
- ↑ She J, Han Z, Kim TW, Wang J, Cheng W, Chang J, Shi S, Wang J, Yang M, Wang ZY, Chai J. Structural insight into brassinosteroid perception by BRI1. Nature. 2011 Jun 12;474(7352):472-6. doi: 10.1038/nature10178. PMID:21666666 doi:10.1038/nature10178
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