Characterisation of mRNAs encoding the precursor for human apolipoprotein CI.

cDNA clones encoding human apolipoprotein CI have been isolated from an adult liver cDNA library. Apo CI mRNA was shown to have two species of approximately 580 and 560 bases by RNA blot hybridisation. The intracellular precursor of apo CI was inferred from the cDNA sequence to be an 83 amino acid polypeptide consisting of the 57 residue mature protein and an additional 26 residue amino terminal signal peptide. The 5' untranslated regions of the messages are 63 and 40 bases as determined by primer extension and the 3' untranslated region 111 bases. A polyadenylation signal is situated 10 bases 3' of the poly(A) tall. The mRNA level of apo CI in human liver was significantly greater than that of apo All and apo E.