title: Novel plant-specific cyclin-dependent kinase inhibitors induced by biotic and abiotic stresses.
abstract: The EL2 gene of rice (Oryza sativa), previously classified as early response gene against the potent biotic elicitor N-acetylchitoheptaose and encoding a short polypeptide with unknown function, was identified as a novel cell cycle regulatory gene related to the recently reported SIAMESE (SIM) gene of Arabidopsis thaliana. Iterative two-hybrid screens, in vitro pull-down assays, and fluorescence resonance energy transfer analyses showed that Orysa; EL2 binds the cyclin-dependent kinase (CDK) CDKA1;1 and D-type cyclins. No interaction was observed with the plant-specific B-type CDKs. The amino acid motif ELERFL was identified to be essential for cyclin, but not for CDK binding. Orysa;EL2 impaired the ability of Orysa; CYCD5;3 to complement a budding yeast (Saccharomyces cerevisiae) triple CLN mutant, whereas recombinant protein inhibited CDK activity in vitro. Moreover, Orysa;EL2 was able to rescue the multicellular trichome phenotype of sim mutants of Arabidopsis, unequivocally demonstrating that Orysa;EL2 operates as a cell cycle inhibitor. Orysa;EL2 mRNA levels were induced by cold, drought, and propionic acid. Our data suggest that Orysa;EL2 encodes a new type of plant CDK inhibitor that links cell cycle progression with biotic and abiotic stress responses.
authors.affiliation: CropDesign N.V., B-9052 Ghent, Belgium.
authors.forename: Adrian
authors.initials: A
authors.lastname: Peres
authors.forename: Michelle L
authors.initials: ML
authors.lastname: Churchman
authors.forename: Srivaidehirani
authors.initials: S
authors.lastname: Hariharan
authors.forename: Kristiina
authors.initials: K
authors.lastname: Himanen
authors.forename: Aurine
authors.initials: A
authors.lastname: Verkest
authors.forename: Klaas
authors.initials: K
authors.lastname: Vandepoele
authors.forename: Zoltan
authors.initials: Z
authors.lastname: Magyar
authors.forename: Yves
authors.initials: Y
authors.lastname: Hatzfeld
authors.forename: Els
authors.initials: E
authors.lastname: Van Der Schueren
authors.forename: Gerrit T S
authors.initials: GT
authors.lastname: Beemster
authors.forename: Valerie
authors.initials: V
authors.lastname: Frankard
authors.forename: John C
authors.initials: JC
authors.lastname: Larkin
authors.forename: Dirk
authors.initials: D
authors.lastname: Inzé
authors.forename: Lieven
authors.initials: L
authors.lastname: De Veylder
mesh_terms: D020816:Amino Acid Motifs; D019943:Amino Acid Substitution; D017360:Arabidopsis / Q000235:genetics / Q000378:metabolism; D029681:Arabidopsis Proteins / Q000235:genetics / Q000378:metabolism; D002453:Cell Cycle / Q000187:drug effects / Q000502:physiology*; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism; D003080:Cold Temperature; D050756:Cyclin-Dependent Kinase Inhibitor Proteins / Q000235:genetics / Q000378:metabolism*; D018844:Cyclin-Dependent Kinases / Q000235:genetics / Q000378:metabolism*; D016213:Cyclins / Q000235:genetics / Q000378:metabolism*; D003681:Dehydration / Q000235:genetics / Q000378:metabolism*; D020125:Mutation, Missense; D009844:Oligosaccharides / Q000378:metabolism / Q000494:pharmacology; D012275:Oryza / Q000235:genetics / Q000378:metabolism*; D011422:Propionates / Q000494:pharmacology; D012441:Saccharomyces cerevisiae / Q000235:genetics; D020798:Two-Hybrid System Techniques
chemical_list: D029681:Arabidopsis Proteins; D018797:Cell Cycle Proteins; D050756:Cyclin-Dependent Kinase Inhibitor Proteins; D016213:Cyclins; C514377:N-acetylchitoheptaose; D009844:Oligosaccharides; D011422:Propionates; C517317:SIAMESE protein, Arabidopsis; D018844:Cyclin-Dependent Kinases; C029658:propionic acid