Sequence homology of the 3 '-untranslated region of calmodulin III in mammals

Calmodulin (CaM) has three separate nonallelic genes that encode for three identical proteins. These genes differ considerably in the 5'- and 3'-untra nslated regions (UTR) and in the promoter region. The sequence of the 3'-UT R of CaM III gene for rat and mouse was completed and compared to the human sequence. The rat and mouse 3'-UTR region had an identity of approximately 80% with the human. Three common polyadenylation signals in the 3'-UTR may account for the multiple CaM III transcripts. Although the untranslated re gions are distinctively different for the three CaM genes, these regions ar e highly conserved among mammals. This high sequence conservation suggests an important function in the localization or regulation of CaM mRNA.