title: CLE14/CLE20 peptides may interact with CLAVATA2/CORYNE receptor-like kinases to irreversibly inhibit cell division in the root meristem of Arabidopsis.
abstract: Towards an understanding of the interacting nature of the CLAVATA (CLV) complex, we predicted the 3D structures of CLV3/ESR-related (CLE) peptides and the ectodomain of their potential receptor proteins/kinases, and docking models of these molecules. The results show that the ectodomain of CLV1 can form homodimers and that the 12-/13-amino-acid CLV3 peptide fits into the binding clefts of the CLV1 dimers. Our results also demonstrate that the receptor domain of CORYNE (CRN), a recently identified receptor-like kinase, binds tightly to the ectodomain of CLV2, and this likely leads to an increased possibility for docking with CLV1. Furthermore, our docking models reveal that two CRN-CLV2 ectodomain heterodimers are able to form a tetramer receptor complex. Peptides of CLV3, CLE14, CLE19, and CLE20 are also able to bind a potential CLV2-CRN heterodimer or heterotetramer complex. Using a cell-division reporter line, we found that synthetic 12-amino-acid CLE14 and CLE20 peptides inhibit, irreversibly, root growth by reducing cell division rates in the root apical meristem, resulting in a short-root phenotype. Intriguingly, we observed that exogenous application of cytokinin can partially rescue the short-root phenotype induced by over-expression of either CLE14 or CLE20 in planta. However, cytokinin treatment does not rescue the short-root phenotype caused by exogenous application of the synthetic CLE14/CLE20 peptides, suggesting a requirement for a condition provided only in living plants. These results therefore imply that the CLE14/CLE20 peptides may act through the CLV2-CRN receptor kinase, and that their availabilities and/or abundances may be affected by cytokinin activity in planta.
authors.affiliation: Department of Plant and Microbial Biology, University of California, CA 94720-3102, USA.
authors.forename: Ling
authors.initials: L
authors.lastname: Meng
authors.forename: Lewis J
authors.initials: LJ
authors.lastname: Feldman
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D002455:Cell Division / Q000235:genetics / Q000502:physiology*; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000502:physiology; D008565:Membrane Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018519:Meristem / Q000166:cytology* / Q000235:genetics / Q000378:metabolism*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008958:Models, Molecular; D018517:Plant Roots / Q000166:cytology* / Q000235:genetics / Q000378:metabolism; D030821:Plants, Genetically Modified / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics / Q000502:physiology*
chemical_list: D029681:Arabidopsis Proteins; C401621:CLV2 protein, Arabidopsis; D008565:Membrane Proteins