Molecular cloning and analysis of Ca2+/calmodulin-dependent protein kinaseII from the chicken brain

The goals of this study were to identify specific mRNAs for isoforms of cal modulin-dependent protein kinase II in chicken forebrain, prepare a cDNA ex pression library, and perform a sequence analysis of the kinase cDNA. Speci fic mRNAs for alpha- and beta-subunits of the kinase were identified in Nor thern blots. The mRNA for the alpha-subunit is larger in the chicken than i n the rat, and for the beta-subunit is smaller in the chicken than the rat. Nucleotide sequencing of selected clones demonstrated the presence of an a lpha-subunit with a 33 nucleotide insert known as the alpha-B-isoform. Clon es of the beta-subunit showed it to contain a deletion of six nucleotides r elative to previously described sequences. Variability in the mRNAs of calm odulin kinase II, as shown here, reflect the presence of species-dependent variability in gene structure as well as the presence of different function al isoforms.