Buffy, a Drosophila Bcl-2 protein, has anti-apoptotic and cell cycle inhibitory functions.
Bcl-2 family proteins are key regulators of apoptosis. Both pro-apoptotic and anti-apoptotic members of this family are found in mammalian cells, but only the pro-apoptotic protein Debcl has been characterized in Drosophila: Here we report that Buffy, the second Drosophila Bcl-2-like protein, is a pro-survival protein. Ablation of Buffy by RNA interference leads to ectopic apoptosis, whereas overexpression of buffy results in the inhibition of developmental programmed cell death and gamma irradiation-induced apoptosis. Buffy interacts genetically and physically with Debcl to suppress Debcl-induced cell death. Genetic interactions suggest that Buffy acts downstream of Rpr, Grim and Hid, and upstream of the apical caspase Dronc. Furthermore, overexpression of buffy inhibits ectopic cell death in diap1 (th(5)) mutants. Taken together these data suggest that Buffy can act downstream of Rpr, Grim and Hid to block caspase-dependent cell death. Overexpression of Buffy in the embryo results in inhibition of the cell cycle, consistent with a G(1)/early-S phase arrest. Our data suggest that Buffy is functionally similar to the mammalian pro-survival Bcl-2 family of proteins.
Quinn
Leonie
L
Trescowick Research Laboratories, Peter MacCallum Cancer Institute, St Andrews Place, East Melbourne.
Coombe
Michelle
M
Mills
Kathryn
K
Daish
Tasman
T
Colussi
Paul
P
Kumar
Sharad
S
Richardson
Helena
H
D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D030801:Animals, Genetically Modified; D017209:Apoptosis / Q000235:genetics / Q000502:physiology* / Q000528:radiation effects; D002453:Cell Cycle / Q000502:physiology*; D002470:Cell Survival / Q000235:genetics; D017124:Conserved Sequence; D004330:Drosophila / Q000196:embryology* / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D005720:Gamma Rays / Q000009:adverse effects; D018507:Gene Expression Regulation, Developmental; D008969:Molecular Sequence Data; D011485:Protein Binding; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D019253:Proto-Oncogene Proteins c-bcl-2 / Q000737:chemistry* / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D017386:Sequence Homology, Amino Acid; D019076:Transgenes
C477358:Buffy protein, Drosophila; D029721:Drosophila Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D012333:RNA, Messenger; D034741:RNA, Small Interfering