The nucleotide sequence of rat liver fatty acid binding protein mRNA

Rat liver fatty acid binding protein mRNA is present in both liver and intestinal epithelium. It is the most abundant mRNA in the small intestinal mucosa. We have determined the sequence of this mRNA from cloned cDNA. It consists of a 5'-nontranslated domain at least 39 nucleotides long, a coding region which specifies a 127-amino acid, 14,184-dalton polypeptide, and a 3'-nontranslated region 68 nucleotides long. An AAUAAA sequence begins 21 nucleotides before the 3'-terminal poly(A) tail. The derived protein sequence was verified by automated sequential Edman degradation of (i) the primary translation product of the mRNA and (ii) a cyanogen bromide peptide generated from the mature liver protein. Evidence is presented which suggests that this protein is targeted to the cytoplasm. The NH2 terminus of the primary translation product is acetylated in vitro. No cleavable signal peptide sequence or internal signal sequence equivalent was detectable in a co-translational cleavage assay. Cloned cDNA was used to establish that this mRNA was 12 times more abundant in intestinal epithelial than in liver RNA.