CLONING AND EXPRESSION OF THE PROGRAMMED CELL-DEATH REGULATOR BAD IN THE RAT-BRAIN

The Bcl-2 family of proteins consists of both antagonists (e.g. Bcl-2) and agonists (e.g. Bar) that regulate apoptosis and compete through d imerization. In the present study we cloned the cDNA encoding the rat brain BAD, a distant member of the Bcl-2 family that was shown to prom ote cell death. The cloned cDNA encoded a protein of 205 amino acids, containing three putative Bcl-2 homology domains (BH1, BH2 and BH3) an d no C-terminal signal-anchor sequence. The predicted amino acid seque nce was identical to the Bad-cDNA recently cloned from the rat ovary w ith the exception of a stretch of six amino acids, thus indicating the existence of two Bad alternative splice variants or a sequence artifa ct in the rat ovary Bad-cDNA. Immunohistochemical analysis in the rat brain revealed the exclusive expression of Bad in the epithelial cells of the choroid plexus, a result which is consistent with a very speci alized function of Bad in the brain. (C) 1998 Elsevier Science Ireland Ltd.