Analysis of transcriptional initiation and translatability of brain-derived neurotrophic factor mRNAs in the rat brain.

The rat brain-derived neurotrophic factor (BDNF) gene consists of four 5' exons linked to separate promoters and one 3' exon encoding the prepro-BDNF protein. In the present study, using RNase protection analysis, we show that the same major transcription initiation sites are used for each BDNF exon mRNA in different brain regions and that in addition to hippocampus and cerebral cortex, kainate differentially induces the expression of BDNF exon mRNAs in thalamus, cerebellum and striatum. The 4.2 kb transcripts, are less enriched in the polysomal fraction of rat brain than the shorter 1.6 kb transcripts suggesting their translational discrimination.