Cyclic nucleotide binding proteins in the Arabidopsis thaliana and Oryza sativa genomes.
BACKGROUND
Cyclic nucleotides are ubiquitous intracellular messengers. Until recently, the roles of cyclic nucleotides in plant cells have proven difficult to uncover. With an understanding of the protein domains which can bind cyclic nucleotides (CNB and GAF domains) we scanned the completed genomes of the higher plants Arabidopsis thaliana (mustard weed) and Oryza sativa (rice) for the effectors of these signalling molecules.


RESULTS
Our analysis found that several ion channels and a class of thioesterases constitute the possible cyclic nucleotide binding proteins in plants. Contrary to some reports, we found no biochemical or bioinformatic evidence for a plant cyclic nucleotide regulated protein kinase, suggesting that cyclic nucleotide functions in plants have evolved differently than in mammals.


CONCLUSIONS
This paper provides a molecular framework for the discussion of cyclic nucleotide function in plants, and resolves a longstanding debate about the presence of a cyclic nucleotide dependent kinase in plants.
Bridges
Dave
D
Department of Biological Sciences, University of Calgary, AB, T2N 1N4 Canada. debridge@ucalgary.ca <debridge@ucalgary.ca>
Fraser
Marie E
ME
Moorhead
Greg B G
GB
D000595:Amino Acid Sequence; D017360:Arabidopsis / Q000235:genetics* / Q000378:metabolism*; D029681:Arabidopsis Proteins / Q000737:chemistry; D015153:Blotting, Western; D002352:Carrier Proteins / Q000737:chemistry* / Q000378:metabolism; D019295:Computational Biology / Q000379:methods*; D000242:Cyclic AMP / Q000378:metabolism; D018506:Gene Expression Regulation, Plant; D017343:Genes, Plant; D016678:Genome; D018745:Genome, Plant; D007473:Ion Channels / Q000737:chemistry; D008969:Molecular Sequence Data; D009712:Nucleotides, Cyclic; D012275:Oryza / Q000235:genetics* / Q000378:metabolism*; D010802:Phylogeny; D010940:Plant Proteins / Q000737:chemistry; D015221:Potassium Channels / Q000737:chemistry; D017434:Protein Structure, Tertiary; D017386:Sequence Homology, Amino Acid; D015398:Signal Transduction; D013869:Thiolester Hydrolases / Q000737:chemistry; D014157:Transcription Factors / Q000737:chemistry
D029681:Arabidopsis Proteins; D002352:Carrier Proteins; D007473:Ion Channels; D009712:Nucleotides, Cyclic; D010940:Plant Proteins; D015221:Potassium Channels; D014157:Transcription Factors; D000242:Cyclic AMP; D013869:Thiolester Hydrolases