Schizosaccharomyces pombe Rad9 contains a BH3-like region and interacts with the anti-apoptotic protein Bcl-2

Here we report that the Schizosaccharomyces pombe Rad9 (SpRad9) protein contains a group of amino acids with similarity to the Bcl-2 homology 3 death domain, which is required for SpRad9 interaction with human Bcl-2 and apoptosis induction in human cells. Overexpression of Bcl-2 in S. pombe inhibits cell growth independently of rad9, but enhances resistance of rad9-null cells to methyl methanesulfonate, ultraviolet and ionizing radiation. These observations suggest that SpRad9 may represent the first member of the Bcl-2 protein family identified in yeast, though the cell death pathways in S, pombe may differ from those found in mammals. (C) 2000 Federation of European Biochemical Societies. Published by Elsevier Science B.V. All rights reserved.