title: CLAVATA1 controls distinct signaling outputs that buffer shoot stem cell proliferation through a two-step transcriptional compensation loop.
abstract: The regulation of stem cell proliferation in plants is controlled by intercellular signaling pathways driven by the diffusible CLAVATA3 (CLV3p) peptide. CLV3p perception is thought to be mediated by an overlapping array of receptors in the stem cell niche including the transmembrane receptor kinase CLV1, Receptor-Like Protein Kinase 2 (RPK2), and a dimer of the receptor-like protein CLV2 and the CORYNE (CRN) pseudokinase. Mutations in these receptors have qualitatively similar effects on stem cell function but it is unclear if this represents common or divergent signaling outputs. Previous work in heterologous systems has suggested that CLV1, RPK2 and CLV2/CRN could form higher order complexes but it is also unclear what relevance these putative complexes have to in vivo receptor functions. Here I use the in vivo regulation of a specific transcriptional target of CLV1 signaling in Arabidopsis to demonstrate that, despite the phenotypic similarities between the different receptor mutants, CLV1 controls distinct signaling outputs in living stem cell niches independent of other receptors. This regulation is separable from stem cell proliferation driven by WUSCHEL, a proposed common transcriptional target of CLV3p signaling. In addition, in the absence of CLV1, CLV1-related receptor kinases are ectopically expressed but also buffer stem cell proliferation through the auto-repression of their own expression. Collectively these data reveal a unique in vivo role for CLV1 separable from other stem cell receptors and provides a framework for dissecting the signaling outputs in stem cell regulation.
authors.affiliation: Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.|Curriculum in Genetics and Molecular Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, United States of America.
authors.forename: Zachary L
authors.identifier: 0000-0003-1826-0671
authors.initials: ZL
authors.lastname: Nimchuk
mesh_terms: D017360:Arabidopsis / Q000166:cytology / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics* / Q000378:metabolism; D049109:Cell Proliferation / Q000235:genetics*; D018506:Gene Expression Regulation, Plant; D018398:Homeodomain Proteins / Q000235:genetics / Q000378:metabolism; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D008957:Models, Genetic; D009154:Mutation; D018520:Plant Shoots / Q000166:cytology / Q000235:genetics* / Q000378:metabolism; D030821:Plants, Genetically Modified; D017346:Protein Serine-Threonine Kinases / Q000235:genetics* / Q000378:metabolism; D011956:Receptors, Cell Surface / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000235:genetics*; D013234:Stem Cells / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; C401621:CLV2 protein, Arabidopsis; D018398:Homeodomain Proteins; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; C116421:WUSCHEL protein, Arabidopsis; C519658:BAM1 protein, Arabidopsis; C519659:BAM2 protein, Arabidopsis; C581880:BAM3 protein, Arabidopsis; C118166:CLV1 protein, Arabidopsis; C548152:CORYNE protein, Arabidopsis; D017346:Protein Serine-Threonine Kinases; C523449:receptor-like protein kinase 2, Arabidopsis