4q5j

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]} [BKI1_ARATH] Negative regulator of brassinosteroid signaling. When associated to the membrane, limits the interaction of BRI1 with BAK1 by binding to the kinase-inactive form of BRI1.^[7]

References

1. ↑ 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
2. ↑ 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
3. ↑ 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
4. ↑ 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
5. ↑ 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
6. ↑ 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
7. ↑ Wang X, Chory J. Brassinosteroids regulate dissociation of BKI1, a negative regulator of BRI1 signaling, from the plasma membrane. Science. 2006 Aug 25;313(5790):1118-22. Epub 2006 Jul 20. PMID:16857903 doi:http://dx.doi.org/10.1126/science.1127593