arabidopsis genetics; Peptide signaling; Signal transduction; Protein crystallography; plant development; Brassinosteroid signaling; plant biochemistry; Receptor kinase
Hohmann Ulrich, Ramakrishna Priya, Wang Kai, Lorenzo-Orts Laura, Nicolet Joel, Henschen Agnes, Barberon Marie, Bayer Martin, Hothorn Michael (2020), Constitutive Activation of Leucine-Rich Repeat Receptor Kinase Signaling Pathways by BAK1-Interacting Receptor-Like Kinase 3 Chimera, in The Plant Cell
Okuda Satohiro, Fujita Satoshi, Moretti Andrea, Hohmann Ulrich, Doblas Verónica G., Ma Yan, Pfister Alexandre, Brandt Benjamin, Geldner Niko, Hothorn Michael (2020), Molecular mechanism for the recognition of sequence-divergent CIF peptides by the plant receptor kinases GSO1/SGN3 and GSO2, in Proceedings of the National Academy of Sciences
, 117(5), 2693-2703.
Doll N. M., Royek S., Fujita S., Okuda S., Chamot S., Stintzi A., Widiez T., Hothorn M., Schaller A., Geldner N., Ingram G. (2020), A two-way molecular dialogue between embryo and endosperm is required for seed development, in Science
, 367(6476), 431-435.
Vaattovaara Aleksia, Brandt Benjamin, Rajaraman Sitaram, Safronov Omid, Veidenberg Andres, Luklová Markéta, Kangasjärvi Jaakko, Löytynoja Ari, Hothorn Michael, Salojärvi Jarkko, Wrzaczek Michael (2019), Mechanistic insights into the evolution of DUF26-containing proteins in land plants, in Communications Biology
, 2(1), 56-56.
Hohmann Ulrich, Nicolet Joël, Moretti Andrea, Hothorn Ludwig A., Hothorn Michael (2018), The SERK3 elongated allele defines a role for BIR ectodomains in brassinosteroid signalling, in Nature Plants
, 4(6), 345-351.
Hohmann Ulrich, Santiago Julia, Nicolet Joël, Olsson Vilde, Spiga Fabio M., Hothorn Ludwig A., Butenko Melinka A., Hothorn Michael (2018), Mechanistic basis for the activation of plant membrane receptor kinases by SERK-family coreceptors, in Proceedings of the National Academy of Sciences
, 115(13), 3488-3493.
Plant as multicellular organisms require to tightly control the division, expansion and differentiation of cells within tissues and organs in order to orchestrate their growth and development. Just like animals, plants have evolved diffusible small molecule, peptide and protein ligands to achieve this goal. These molecules are sensed by plant-unique membrane receptor kinases (RKs). Plant RKs contain different extracellular ligand-binding domains, a single membrane-spanning helix and a cytoplasmic kinase domain. We have previously shown how plant RKs with leucine-rich repeat (LRR) ectodomains can specifically sense steroid and peptide ligands and we have demonstrated that different LRR-RKs require shape-complementary co-receptors for high-affinity ligand sensing and receptor activation. Using the plant brassinosteroid signaling pathway as a model system, we now propose to dissect in genetic and mechanistic detail (sub-project A):(1) how additional membrane proteins can modulate the signaling capacity of LRR-RK - co-receptor complexes (formation of higher-order signaling complexes).(2) how ligand induced interaction of receptor and co-receptor at the cell surface leads to activation of the cytoplasmic kinase domain of the receptor and to phosphorylation of down-stream components (early cytoplasmic signaling events).(3) how activation of the cytoplasmic kinase domain leads to the activation of gene expression (mechanism of the cytoplasmic signaling cascade).In addition, we want to understand the functions of plant RKs with different ectodomains (non-LRR) in plant growth and development. Specifically, we propose (sub-project B):(1) to uncover the molecular architecture of CRINKLY-type RKs (CRINKLY structure).(2) to identify and characterize CRINKLY-family ligands and define the receptor activation mechanism (CRINKLY ligands & activation).(3) to define down-stream signaling components for CRINKLY-receptors (CRINKLY cytoplasmic signaling).To achieve these goals, we will combine quantitative biochemistry and X-ray protein crystallography in vitro, with plant biochemistry and genetics in vivo. This will allow us to dissect from the physiological all the way to the mechanistic level, how different membrane signaling proteins with key roles in growth and development translate the binding of specific ligands at the cell surface into gene expression changes in the nucleus. Our work may uncover novel signaling paradigms in plants and may suggest new ways to modulate plant growth and development in the lab, and perhaps, in the field.