title: Differential CLE peptide perception by plant receptors implicated from structural and functional analyses of TDIF-TDR interactions.
abstract: Tracheary Element Differentiation Inhibitory Factor (TDIF) belongs to the family of post-translationally modified CLE (CLAVATA3/embryo surrounding region (ESR)-related) peptide hormones that control root growth and define the delicate balance between stem cell proliferation and differentiation in SAM (shoot apical meristem) or RAM (root apical meristem). In Arabidopsis, Tracheary Element Differentiation Inhibitory Factor Receptor (TDR) and its ligand TDIF signaling pathway is involved in the regulation of procambial cell proliferation and inhibiting its differentiation into xylem cells. Here we present the crystal structures of the extracellular domains (ECD) of TDR alone and in complex with its ligand TDIF resolved at 2.65 Ǻ and 2.75 Ǻ respectively. These structures provide insights about the ligand perception and specific interactions between the CLE peptides and their cognate receptors. Our in vitro biochemical studies indicate that the interactions between the ligands and the receptors at the C-terminal anchoring site provide conserved binding. While the binding interactions occurring at the N-terminal anchoring site dictate differential binding specificities between different ligands and receptors. Our studies will open different unknown avenues of TDR-TDIF signaling pathways that will enhance our knowledge in this field highlighting the receptor ligand interaction, receptor activation, signaling network, modes of action and will serve as a structure function relationship model between the ligand and the receptor for various similar leucine-rich repeat receptor-like kinases (LRR-RLKs).
authors.affiliation: Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Zhijie
authors.initials: Z
authors.lastname: Li
authors.affiliation: Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Sayan
authors.initials: S
authors.lastname: Chakraborty
authors.affiliation: Department of Molecular and Structural Biochemistry, North Carolina State University, Raleigh, North Carolina, United States of America.
authors.forename: Guozhou
authors.identifier: http://orcid.org/0000-0003-4939-5982
authors.initials: G
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism*; D001665:Binding Sites; D015394:Molecular Structure; D011485:Protein Binding; D011494:Protein Kinases / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid
chemical_list: C118167:AT2G27250 protein, Arabidopsis; D029681:Arabidopsis Proteins; D011494:Protein Kinases; C524131:PXY protein, Arabidopsis