Cloning and Characterization of a cDNA Encoding a Novel Fatty Acid Binding Protein from Rat Brain

Abstract

<jats:p><jats:bold>Abstract:</jats:bold> We have adopted a polymerase chain reaction approach to identify and clone a cDNA that contains the complete coding sequence of a novel fatty acid binding protein (FABP) from a rat brain λgt10 library. Sequencing of the brain FABP (B‐FABP) cDNA revealed an open reading frame coding for a protein with 132 amino acids and a predicted size of ∼15,000 Da. This putative protein shares extensive sequence homology with other members of the FABP family. Northern blot analysis using the B‐FABP cDNA as a probe established the presence of an abundant mRNA ∼0.8 kb long in rat brain and in the MOCH‐1 oligodendrocyte cell line. This transcript was also present in rat liver but not in other tissues examined. A developmental profile of this mRNA in rat brain demonstrated detectable expression in 15‐day‐old embryos with levels peaking in 1‐day postnatal neonates and declining thereafter, reaching a low steady‐state level at 3 weeks of age. In situ hybridization histochemistry revealed B‐FABP mRNA in various brain regions, with the highest levels in fiber tracts. The B‐FABP message was also detected at a lower level in several gray matter regions. The cloning approach used in this study would likely be useful in the identification and isolation of FABP‐encoding genes from other tissues and species.</jats:p>