Multiple mRNAs encoding human calmodulin.

In humans, as in rats, four distinct molecular weight species of mRNA encoding calmodulin exist, i.e. 1.6 Kb for L, 1.4 Kb for T2 and 2.5 and 1.0 Kb for T1. They result from the expression of three genes. Each of these mRNAs codes for a calmodulin identical in amino acid sequence. The 5' and 3' untranslated regions of these mRNAs, however, differ extensively, and oligonucleotide probes specific to these regions were used in this study. The poly A+ mRNA was isolated from human erythroleukemia cells and also from human B cells infected with EBV.