Novel Plant-specific Cyclin-dependent Kinase Inhibitors Induced by Biotic and Abiotic Stresses

• Published in: The Journal of biological chemistry Vol. 282; no. 35; pp. 25588 - 25596
• Main Authors: Peres, Adrian, Churchman, Michelle L., Hariharan, Srivaidehirani, Himanen, Kristiina, Verkest, Aurine, Vandepoele, Klaas, Magyar, Zoltan, Hatzfeld, Yves, Van Der Schueren, Els, Beemster, Gerrit T.S., Frankard, Valerie, Larkin, John C., Inzé, Dirk, De Veylder, Lieven
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 31.08.2007; American Society for Biochemistry and Molecular Biology
• Subjects: Amino Acid Motifs; Amino Acid Substitution; Arabidopsis - genetics; Arabidopsis - metabolism; Arabidopsis Proteins - genetics; Arabidopsis Proteins - metabolism; Arabidopsis thaliana; Cell Cycle - drug effects; Cell Cycle - physiology; Cell Cycle Proteins - genetics; Cell Cycle Proteins - metabolism; Cold Temperature; Cyclin-Dependent Kinase Inhibitor Proteins - genetics; Cyclin-Dependent Kinase Inhibitor Proteins - metabolism; Cyclin-Dependent Kinases - genetics; Cyclin-Dependent Kinases - metabolism; Cyclins - genetics; Cyclins - metabolism; Dehydration - genetics; Dehydration - metabolism; Freshwater; Mutation, Missense; Oligosaccharides - metabolism; Oligosaccharides - pharmacology; Oryza - genetics; Oryza - metabolism; Oryza sativa; Propionates - pharmacology; Saccharomyces cerevisiae; Saccharomyces cerevisiae - genetics; Two-Hybrid System Techniques
• ISSN: 0021-9258; 1083-351X
• DOI: 10.1074/jbc.M703326200

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.