Fig. 3: OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 act as ligands to directly bind the OsER1 receptor.
From: Optimization of rice panicle architecture by specifically suppressing ligand–receptor pairs
a–d Quantification of the binding affinity of OsER1LRR for OsEPFL6 (a), OsEPFL7 (b), OsEPFL8 (c), and OsEPFL9 (d) as measured with isothermal titration calorimetry (ITC) assays. Purified OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 small peptides were separately titrated into OsER1LRR protein in the ITC cell. Raw data and integrated heat measurements are shown in the upper and lower panels, respectively. The calculated stoichiometry (N) and the dissociation constants (Kd) are indicated. e Gel filtration showing that OsEPFL6, OsEPFL7, OsEPFL8, and OsEPFL9 directly bind to OsER1LRR. The elution volumes and the molecular weight markers are indicated at the top. Size exclusion chromatography analysis of the interactions between OsEPFL6 and OsER1LRR, OsEPFL7 and OsER1LRR, OsEPFL8, and OsER1LRR, and OsEPFL9 and OsER1LRR are shown in the lower panel. The middle panel shows peak fractions from the lower panel analyzed by SDS-PAGE with Coomassie brilliant blue staining corresponding to OsER1LRR alone, OsEPFL6–OsER1LRR, OsEPFL7–OsER1LRR, OsEPFL8–OsER1LRR, and OsEPFL9–OsER1LRR. f–i Co-IP assays indicating that OsEPFL6 (f), OsEPFL7 (g), OsEPFL8 (h), and OsEPFL9 (i) each interact with OsER1LRR in planta. Pro35S::OsER1LRR-Flag was co-expressed with Pro35S::OsEPFL6-Myc, Pro35S::OsEPFL7-Myc, Pro35S::OsEPFL8-Myc, or Pro35S::OsEPFL9-Myc in N. benthamiana leaves. Proteins were extracted (Input) and immunoprecipitated (IP) with Flag beads. Immunoblots were performed using anti-Flag and anti-Myc antibodies. In e–i, three independent experiments were repeated with similar results. The source data underlying the statistical analysis in e and uncropped images in f–i are provided in the Source Data file.
