IDENTIFICATION OF AN ALTERNATIVE FORM OF THE DROSOPHILA CA2-DEPENDENTPROTEIN-KINASE-II THAT IS MATERNALLY DERIVED( CALMODULIN)

Four forms of the Drosophila Ca2+/calmodulin-dependent protein kinase II are generated from a single gene by alternative splicing (Ohsako et al. (1993) J. Biol. Chem. 268, 2052-2062). We identified a fifth form of the cDNA encoding the enzyme expressed in the ovary, unfertilized egg and early embryos by reverse transcription-polymerase chain reacti on, which suggests that it is maternally derived. The fifth form was a lso generated from the gene by alternative splicing and was identical to the cDNA encoding the 530-amino-acid polypeptide, the longest of th e four forms previously identified, except that it lacked exon 11. Thr ee splicing derivatives which lost one amino acid from the 509- and 53 0-amino-acid polypeptides were also found in 4 to 10 h embryos.