title: Arabidopsis PIAL1 and 2 promote SUMO chain formation as E4-type SUMO ligases and are involved in stress responses and sulfur metabolism.
abstract: The Arabidopsis thaliana genes PROTEIN INHIBITOR OF ACTIVATED STAT LIKE1 (PIAL1) and PIAL2 encode proteins with SP-RING domains, which occur in many ligases of the small ubiquitin-related modifier (SUMO) conjugation pathway. We show that PIAL1 and PIAL2 function as SUMO ligases capable of SUMO chain formation and require the SUMO-modified SUMO-conjugating enzyme SCE1 for optimal activity. Mutant analysis indicates a role for PIAL1 and 2 in salt stress and osmotic stress responses, whereas under standard conditions, the mutants show close to normal growth. Mutations in PIAL1 and 2 also lead to altered sulfur metabolism. We propose that, together with SUMO chain binding ubiquitin ligases, these enzymes establish a pathway for proteolytic removal of sumoylation substrates.
authors.affiliation: Max F. Perutz Laboratories, Center for Molecular Biology of the University of Vienna, A-1030 Vienna, Austria.
authors.forename: Konstantin
authors.initials: K
authors.lastname: Tomanov
authors.affiliation: Department of Molecular Plant Physiology, Max Planck Institute for Molecular Plant Physiology, D-14476 Potsdam, Germany.
authors.forename: Anja
authors.initials: A
authors.lastname: Zeschmann
authors.affiliation: Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany.
authors.forename: Rebecca
authors.initials: R
authors.lastname: Hermkes
authors.affiliation: Max F. Perutz Laboratories, Center for Molecular Biology of the University of Vienna, A-1030 Vienna, Austria Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany.
authors.forename: Karolin
authors.initials: K
authors.lastname: Eifler
authors.affiliation: Max F. Perutz Laboratories, Center for Molecular Biology of the University of Vienna, A-1030 Vienna, Austria.
authors.forename: Ionida
authors.initials: I
authors.lastname: Ziba
authors.affiliation: Department of Ecogenomics and Systems Biology, University of Vienna, A-1090 Vienna, Austria.
authors.forename: Michele
authors.initials: M
authors.lastname: Grieco
authors.affiliation: Research Institute of Molecular Pathology, A-1030 Vienna, Austria.
authors.forename: Maria
authors.initials: M
authors.lastname: Novatchkova
authors.affiliation: Institute for Genetics, University of Cologne, D-50674 Cologne, Germany.
authors.forename: Kay
authors.initials: K
authors.lastname: Hofmann
authors.affiliation: Department of Molecular Plant Physiology, Max Planck Institute for Molecular Plant Physiology, D-14476 Potsdam, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Hesse
authors.affiliation: Max F. Perutz Laboratories, Center for Molecular Biology of the University of Vienna, A-1030 Vienna, Austria Department of Plant Developmental Biology, Max Planck Institute for Plant Breeding Research, D-50829 Cologne, Germany andreas.bachmair@univie.ac.at.
authors.forename: Andreas
authors.initials: A
authors.lastname: Bachmair
mesh_terms: D017360:Arabidopsis / Q000201:enzymology* / Q000235:genetics / Q000502:physiology; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism*; D008958:Models, Molecular; D016254:Mutagenesis, Insertional; D010802:Phylogeny; D036226:Seedlings / Q000201:enzymology / Q000235:genetics / Q000502:physiology; D013312:Stress, Physiological; D013455:Sulfur / Q000378:metabolism*; D058207:Sumoylation; D025801:Ubiquitin / Q000378:metabolism*; D044763:Ubiquitin-Conjugating Enzymes / Q000235:genetics / Q000378:metabolism*; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*
chemical_list: D029681:Arabidopsis Proteins; D025801:Ubiquitin; D013455:Sulfur; D044763:Ubiquitin-Conjugating Enzymes; D044767:Ubiquitin-Protein Ligases