Differential regulation of the two mRNA species of the rodent negative acute phase protein α1-inhibitor 3

AbstractScreening of two rat liver cDNA libraries, one of which was constructed using an α1-inhibitor 3 (α1-I3) specific primer, yielded overlapping cDNA clones which correspond to the full length cDNA for α1-I3 mRNA. On the basis of sequence microheterogeneity existing throughout the cDNA sequence we identified two α1-I3 mRNA species whose sequences are so grossly different in their bait regions that the amino acid homology therein is only 30%. Using oligonucleotide probes derived from their respective bait regions we investigated the regulation of the two α1 I3 mRNA species and demonstrated that only one of them, α1-I3 variant I, is regulated pretranslationally following experimentally induced inflammation