2013 journal article

The BRASSINOSTEROID INSENSITIVE1-LIKE3 Signalosome Complex Regulates Arabidopsis Root Development

PLANT CELL, 25(9), 3377–3388.

co-author countries: Spain 🇪🇸 Netherlands 🇳🇱 United States of America 🇺🇸
MeSH headings : Arabidopsis / cytology; Arabidopsis / genetics; Arabidopsis / growth & development; Arabidopsis / metabolism; Arabidopsis Proteins / genetics; Arabidopsis Proteins / metabolism; Brassinosteroids / metabolism; Cell Cycle; Chromatography, Liquid; Gene Expression Regulation, Plant; Genes, Reporter; Multiprotein Complexes; Mutation; Phenotype; Phloem / cytology; Phloem / genetics; Phloem / growth & development; Phloem / metabolism; Plant Roots / cytology; Plant Roots / genetics; Plant Roots / growth & development; Plant Roots / metabolism; Plants, Genetically Modified; Protein Interaction Mapping; Protein Serine-Threonine Kinases / genetics; Protein Serine-Threonine Kinases / metabolism; Receptors, Cell Surface / genetics; Receptors, Cell Surface / metabolism; Recombinant Fusion Proteins; Signal Transduction; Tandem Mass Spectrometry
Source: Web Of Science
Added: August 6, 2018

Brassinosteroid (BR) hormones are primarily perceived at the cell surface by the leucine-rich repeat receptor-like kinase brassinosteroid insensitive1 (BRI1). In Arabidopsis thaliana, BRI1 has two close homologs, BRI1-LIKE1 (BRL1) and BRL3, respectively, which are expressed in the vascular tissues and regulate shoot vascular development. Here, we identify novel components of the BRL3 receptor complex in planta by immunoprecipitation and mass spectrometry analysis. Whereas BRI1 associated kinase1 (BAK1) and several other known BRI1 interactors coimmunoprecipitated with BRL3, no evidence was found of a direct interaction between BRI1 and BRL3. In addition, we confirmed that BAK1 interacts with the BRL1 receptor by coimmunoprecipitation and fluorescence microscopy analysis. Importantly, genetic analysis of brl1 brl3 bak1-3 triple mutants revealed that BAK1, BRL1, and BRL3 signaling modulate root growth and development by contributing to the cellular activities of provascular and quiescent center cells. This provides functional relevance to the observed protein-protein interactions of the BRL3 signalosome. Overall, our study demonstrates that cell-specific BR receptor complexes can be assembled to perform different cellular activities during plant root growth, while highlighting that immunoprecipitation of leucine-rich repeat receptor kinases in plants is a powerful approach for unveiling signaling mechanisms with cellular resolution in plant development.