Authors: Ling Meng Lewis J Feldman
Publish Date: 2010/08/10
Volume: 232, Issue: 5, Pages: 1061-1074
Abstract
Towards an understanding of the interacting nature of the CLAVATA CLV complex we predicted the 3D structures of CLV3/ESRrelated 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 12/13aminoacid 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 receptorlike 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 CRNCLV2 ectodomain heterodimers are able to form a tetramer receptor complex Peptides of CLV3 CLE14 CLE19 and CLE20 are also able to bind a potential CLV2CRN heterodimer or heterotetramer complex Using a celldivision reporter line we found that synthetic 12aminoacid CLE14 and CLE20 peptides inhibit irreversibly root growth by reducing cell division rates in the root apical meristem resulting in a shortroot phenotype Intriguingly we observed that exogenous application of cytokinin can partially rescue the shortroot phenotype induced by overexpression of either CLE14 or CLE20 in planta However cytokinin treatment does not rescue the shortroot 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 CLV2CRN receptor kinase and that their availabilities and/or abundances may be affected by cytokinin activity in planta
Keywords: