title: Manipulation of mitogen-activated protein kinase kinase signaling in the Arabidopsis stomatal lineage reveals motifs that contribute to protein localization and signaling specificity.
abstract: When multiple mitogen-activated protein kinase (MAPK) components are recruited recurrently to transduce signals of different origins, and often opposing outcomes, mechanisms to enforce signaling specificity are of utmost importance. These mechanisms are largely uncharacterized in plant MAPK signaling networks. The Arabidopsis thaliana stomatal lineage was previously used to show that when rendered constitutively active, four MAPK kinases (MKKs), MKK4/5/7/9, are capable of perturbing stomatal development and that these kinases comprise two pairs, MKK4/5 and MKK7/9, with both overlapping and divergent functions. We characterized the contributions of specific structural domains of these four "stomatal" MKKs to MAPK signaling output and specificity both in vitro and in vivo within the three discrete cell types of the stomatal lineage. These results verify the influence of functional docking (D) domains of MKKs on MAPK signal output and identify novel regulatory functions for previously uncharacterized structures within the N termini of MKK4/5. Beyond this, we present a novel function of the D-domains of MKK7/9 in regulating the subcellular localization of these kinases. These results provide tools to broadly assess the extent to which these and additional motifs within MKKs function to regulate MAPK signal output throughout the plant.
authors.affiliation: Howard Hughes Medical Institute, Stanford University, Stanford, California 94305-5020.
authors.forename: Gregory R
authors.initials: GR
authors.lastname: Lampard
authors.affiliation: Howard Hughes Medical Institute, Stanford University, Stanford, California 94305-5020.
authors.forename: Diego L
authors.initials: DL
authors.lastname: Wengier
authors.affiliation: Howard Hughes Medical Institute, Stanford University, Stanford, California 94305-5020 Department of Biology, Stanford University, Stanford, California 94305-5020 dbergmann@stanford.edu.
authors.forename: Dominique C
authors.initials: DC
authors.lastname: Bergmann
mesh_terms: D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000166:cytology / Q000378:metabolism* / Q000502:physiology; D029681:Arabidopsis Proteins / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D001665:Binding Sites; D017353:Gene Deletion; D048688:MAP Kinase Kinase 7 / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D020935:MAP Kinase Signaling System; D020929:Mitogen-Activated Protein Kinase Kinases / Q000737:chemistry* / Q000378:metabolism / Q000502:physiology; D020928:Mitogen-Activated Protein Kinases / Q000737:chemistry / Q000378:metabolism / Q000502:physiology; D008969:Molecular Sequence Data; D054046:Plant Stomata / Q000166:cytology / Q000378:metabolism / Q000502:physiology; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D016415:Sequence Alignment
chemical_list: D029681:Arabidopsis Proteins; D020928:Mitogen-Activated Protein Kinases; C512166:BUD1 protein, Arabidopsis; D048688:MAP Kinase Kinase 7; C519871:MKK4 protein, Arabidopsis; C519872:MKK5 protein, Arabidopsis; C527379:MKK9 protein, Arabidopsis; D020929:Mitogen-Activated Protein Kinase Kinases