Cytokinin oxidase from Zea mays: purification, cDNA cloning and expression in moss protoplasts
Year: 1999
Type: article
Abstract: Cytokinins are degraded by cytokinin oxidases (CKOs) which catalyse cleavage of the N6-(isopent-2-enyl)-side chain resulting in formation of adenine-type compounds. CKO activity has been recorded in many plants and is thought to play a key role in controlling cytokinin levels in plants. Several partially purified CKOs have been characterised but no genes have been isolated yet. CKO activity is known to be inhibited by phenylureas, cytokinin agonists. We used 1-(2-azido-6-chloropyrid-4-yl)-3-(4-[3H])phenylurea ([3H]-azidoCPPU) to photolabel a glycosylated CKO from maize kernels. This enabled us to purify the enzyme. Peptide sequences were determined and the corresponding cDNA was cloned. The deduced amino acid sequence shares homology domains with FAD-dependent oxidases. An original assay based on transient expression of the enzyme in moss protoplasts allowed the functionality of the recombinant enzyme to be demonstrated.
Source: The Plant Journal
Language: English
Subfield: Plant Science
Domain: Life Sciences
Open Access status: bronze
OpenAlex ID: W2030356145