Fluorescent castasterone reveals BRI1 signaling from the plasma membrane

0378975 - ÚOCHB 2013 RIV US eng J - Journal Article
Irani, N. G. - Di Rubbo, S. - Mylle, E. - Van den Begin, J. - Schneider-Pizon, J. - Hniličková, Jaroslava - Šíša, Miroslav - Buyst, D. - Vilarrasa-Blasi, J. - Szatmári, A. M. - Van Damme, D. - Mishev, K. - Codreanu, M. C. - Kohout, Ladislav - Strnad, Miroslav - Cano-Delgado, A. I. - Friml, J. - Madder, A. - Russinova, E.
Fluorescent castasterone reveals BRI1 signaling from the plasma membrane.
Nature Chemical Biology. Roč. 8, č. 6 (2012), s. 583-589. ISSN 1552-4450. E-ISSN 1552-4469
R&D Projects: GA MŠMT 1M06030
Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z50380511
Keywords : receptor kinase BRI1 * steroid-binding protein-1 * plant-cells * brassinosteroid biosynthesis * dependent endocytosis * auxin transport * Arabidopsis
Subject RIV: CC - Organic Chemistry
Impact factor: 12.948, year: 2012

Receptor-mediated endocytosis is an integral part of signal transduction as it mediates signal attenuation and provides spatial and temporal dimensions to signaling events. One of the best-studied leucine-rich repeat receptor-like kinases in plants, BRASSINOSTEROID INSENSITIVE 1 (BRI1), perceives its ligand, the brassinosteroid (BR) hormone, at the cell surface and is constitutively endocytosed. However, the importance of endocytosis for BR signaling remains unclear. Here we developed a bioactive, fluorescent BR analog, Alexa Fluor 647-castasterone (AFCS), and visualized the endocytosis of BRI1-AFCS complexes in living Arabidopsis thaliana cells. Impairment of endocytosis dependent on clathrin and the guanine nucleotide exchange factor for ARF GTPases (ARF-GEF) GNOM enhanced BR signaling by retaining active BRI1-ligand complexes at the plasma membrane. Increasing the trans-Golgi network/early endosome pool of BRI1-BR complexes did not affect BR signaling. Our findings provide what is to our knowledge the first visualization of receptor-ligand complexes in plants and reveal clathrin- and ARF-GEF-dependent endocytic regulation of BR signaling from the plasma membrane.
Permanent Link: http://hdl.handle.net/11104/0210273