title: The mRNA decay factor PAT1 functions in a pathway including MAP kinase 4 and immune receptor SUMM2.
abstract: Multi-layered defense responses are activated in plants upon recognition of invading pathogens. Transmembrane receptors recognize conserved pathogen-associated molecular patterns (PAMPs) and activate MAP kinase cascades, which regulate changes in gene expression to produce appropriate immune responses. For example, Arabidopsis MAP kinase 4 (MPK4) regulates the expression of a subset of defense genes via at least one WRKY transcription factor. We report here that MPK4 is found in complexes in vivo with PAT1, a component of the mRNA decapping machinery. PAT1 is also phosphorylated by MPK4 and, upon flagellin PAMP treatment, PAT1 accumulates and localizes to cytoplasmic processing (P) bodies which are sites for mRNA decay. Pat1 mutants exhibit dwarfism and de-repressed immunity dependent on the immune receptor SUMM2. Since mRNA decapping is a critical step in mRNA turnover, linking MPK4 to mRNA decay via PAT1 provides another mechanism by which MPK4 may rapidly instigate immune responses.
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Milena Edna
authors.initials: ME
authors.lastname: Roux
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Magnus Wohlfahrt
authors.initials: MW
authors.lastname: Rasmussen
authors.affiliation: New England Biolabs Ltd, Whitby, ON, Canada.
authors.forename: Kristoffer
authors.initials: K
authors.lastname: Palma
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Signe
authors.initials: S
authors.lastname: Lolle
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Àngels Mateu
authors.initials: ÀM
authors.lastname: Regué
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN, USA.
authors.forename: Gerit
authors.initials: G
authors.lastname: Bethke
authors.affiliation: Department of Plant Biology, University of Minnesota, St. Paul, MN, USA.
authors.forename: Jane
authors.initials: J
authors.lastname: Glazebrook
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT, USA.
authors.forename: Weiping
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Department of Biology, University of Utah, Salt Lake City, UT, USA.
authors.forename: Leslie
authors.initials: L
authors.lastname: Sieburth
authors.affiliation: University of Southern Denmark Institute for Biochemistry and Molecular Biology, Odense, Denmark.
authors.forename: Martin R
authors.initials: MR
authors.lastname: Larsen
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark.
authors.forename: John
authors.initials: J
authors.lastname: Mundy
authors.affiliation: Department of Biology, Faculty of Science, University of Copenhagen, Copenhagen, Denmark shutko@bio.ku.dk.
authors.forename: Morten
authors.initials: M
authors.lastname: Petersen
mesh_terms: D017360:Arabidopsis / Q000235:genetics / Q000254:growth & development / Q000276:immunology*; D029681:Arabidopsis Proteins / Q000276:immunology / Q000378:metabolism*; D002352:Carrier Proteins / Q000276:immunology / Q000378:metabolism*; D003001:Cloning, Molecular; D017931:DNA Primers / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D018506:Gene Expression Regulation, Plant / Q000235:genetics / Q000276:immunology*; D005838:Genotype; D015151:Immunoblotting; D013058:Mass Spectrometry; D018613:Microscopy, Confocal; D020928:Mitogen-Activated Protein Kinases / Q000276:immunology / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D010834:Phytochrome / Q000276:immunology / Q000378:metabolism*; D030821:Plants, Genetically Modified; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction / Q000235:genetics / Q000276:immunology*; D015003:Yeasts
chemical_list: D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D017931:DNA Primers; C409842:PAT1 protein, Arabidopsis; C573316:SUMM2 protein, Arabidopsis; D010834:Phytochrome; C436292:AtMPK4 protein, Arabidopsis; D020928:Mitogen-Activated Protein Kinases
keywords: MAP kinases; decapping; immunity; mRNA decay; phosphorylation