Molecular Cloning and Characterization of a Caimodulin Gene from Arabidopsis thaliana

The calcium binding protein, caimodulin is involved in regulating various cellular and biochemical processes. A gene tor caimodulin (CaM) has been Isolated from a genomic library of Arabidopsis thaliana constructed in λ EMBL-4 using a heterologous cDNA probe from electric eel. One of the positive clones was characterized and the region containing the caimodulin gene sequences was identified, excised using appropriate restriction enzymes and subcloned Into a plasmid vector. The genomic clone contains a complete copy of the caimodulin gene. A comparison of the nucleotide sequence of the part of the clone with those of the other plant and animal systems confirms that the clone in fact contains the caimodulin gene sequences. Southern hybridization using the caimodulin gene sequences as a probe reveals the presence of more than one copy of the calmodulin gene. The results of this investigation taken together with those of the others indicate that the calmodulin gene belongs to a small mutigene family consisting of atleast four members In the Arabidopsis genome.