title: Signaling of cell fate determination by the TPD1 small protein and EMS1 receptor kinase.
abstract: Sexual reproduction requires the specification of cells with distinct fates in plants and animals. The EMS1 (also known as EXS) leucine-rich repeat receptor-like kinase (LRR-RLK) and TPD1 small protein play key roles in regulating somatic and reproductive cell fate determination in Arabidopsis anthers. Here, we show that ectopic expression of TPD1 causes abnormal differentiation of somatic and reproductive cells in anthers. In addition, ectopic TPD1 activity requires functional EMS1. Yeast two-hybrid, pull-down, and coimmunoprecipitation analyses further demonstrate that TPD1 interacts with EMS1 in vitro and in vivo. Moreover, TPD1 induces EMS1 phosphorylation in planta. Thus, our results suggest that TPD1 serves as a ligand for the EMS1 receptor kinase to signal cell fate determination during plant sexual reproduction.
authors.affiliation: Department of Biological Sciences, University of Wisconsin, Milwaukee, WI 53211, USA.
authors.forename: Gengxiang
authors.initials: G
authors.lastname: Jia
authors.forename: Xiaodong
authors.initials: X
authors.lastname: Liu
authors.forename: Heather A
authors.initials: HA
authors.lastname: Owen
authors.forename: Dazhong
authors.initials: D
authors.lastname: Zhao
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000502:physiology*; D002454:Cell Differentiation; D019070:Cell Lineage / Q000502:physiology*; D018076:DNA, Complementary; D008024:Ligands; D010766:Phosphorylation; D030821:Plants, Genetically Modified; D011494:Protein Kinases / Q000235:genetics / Q000502:physiology*; D012098:Reproduction; D015398:Signal Transduction / Q000502:physiology*; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D018076:DNA, Complementary; D008024:Ligands; D011494:Protein Kinases; C483722:Tapetum determinant1 protein, Arabidopsis; C464786:At5g07280 protein, Arabidopsis