Isolation and sequence of a full length cDNA encoding a novel rat inositol 1,4,5-trisphosphate 3-kinase

Immunoscreening a rat liver cDNA expression library has led to the isolation of a full-length cDNA clone encoding a novel isoform of rat inositol 1,4,5-trisphosphate 3-kinase (IP3 3-kinase). Sequence comparison shows it (i) to be 93% identical to human hippocampus IP3 3-kinase B over 468 residues at the protein level, and (ii) to encode a protein 204 amino acids larger than the published sequence of its human homologue.