One of the surprising findings in characterizing the sequences encoding calmodulin in Arabidopsis was the unexpected, large size of the calmodulin gene family.  The calmodulin and calmodulin-like sequences below are listed because the proteins share at least 50% amino acid sequence identity in the regions corresponding to typical calmodulin proteins.  Similar to vertebrates (including humans), Arabidopsis possess three calmodulin genes (Cam2, 3 and 5) that encode identical polypeptides; the identities and similarities of other calmodulins and calmodulin-like proteins in Arabidopsis to Cam2, 3 and 5 are indicated in the table below.  One of our goals is to understand what function this large gene family serves in plants, and what roles are played by the different calmodulin isoforms.

The table below identifies genomic and cDNA sequences encoding calmodulin from Arabidopsis that were characterized by either the Arabidopsis sequencing effort or our lab.  Genomic and cDNA clones are available from the Arabidopsis Biological Resource Center (ABRC).  T-DNA insertional knockouts are available for most of the AtCam genes and were constructed at the Salk Institute Genomic Analysis Laboratory (SIGnAL, labeled "SALK"). Others were constructed through the German Plant Genomics Program of BMBF (labeled "GABI") or the Genetics and Plant Breeding laboratory (INRA Versailles, labeled "FLAG"). These are listed and hyperlinked in the table.

^aB, calmodulin function determined by biochemical activity; Y, calmodulin function determined by yeast complementation; n.d., not determined

References:

Buaboocha, T. and Zielinski, R. E. (2002) Calmodulin.  In: Protein-Protein Interactions in Plant Biology, (M.T. McManus, W. Liang, A. Allan, eds,) Sheffield Academic Press, Sheffield, UK, pp. 284-313.