Role of mitochondria and C‐terminal membrane anchor of Bcl‐2 in Bax induced growth arrest and mortality in Saccharomyces cerevisiae

FEBS Letters

Stephan, Christine¹  Chaudhuri, Bhabatosh¹  Greenhalf, William¹ 

[1] Department of Core Drug Discovery Technologies (CDDT), Ciba-Geigy AG, Basel, Switzerland

关键词: Apoptosis;    Bax;    Bcl-2 family;    Membrane-anchor;    Mitochondrion;    Saccharomyces cerevisiae;    Bax;    protein encoded by human Bax-α gene;    Bcl-x(L);    human Bcl-x(L) protein;    Bi;    yeast strain with integrated copy of GAL10p-Bax expression cassette;    CYP1p;    promoter from yeast cytosolic cyclophilin gene;    GAL10p;    promoter from yeast GAL10 gene;    Gal;    galactose;    GAPDHp;    promoter from yeast glyceraldehyde-3-phosphate dehydrogenase gene;    Glu;    glucose;    hBcl-2;    human Bcl-2 protein;    hma;    human Bcl-2 membrane anchor;    mBcl-2;    murine Bcl-2 protein;    mma;    yeast Mas70 protein membrane anchor;    PCR;    polymerase chain reaction;    PCD;    programmed cell death;   

DOI  :  10.1016/0014-5793(96)00044-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In mammalian cells, the Bcl-2 and Bcl-x(L) proteins suppress programmed cell death whereas the topographically similar Bax protein accelerates the apoptotic process. Recently published data suggest that expression of the human Bax-α gene is lethal for the yeast can be overcome by co-expressing Bcl-2 or Bcl-x(L). Our findings corroborate these results. However, we find that although Bax induction invariably stops cell growth under all circumstances, it does not lead to death in ‘petite’ cell. Petites cannot respire because they lack functional mitochondria. It seems that in ‘grande’ cells, which do possess normal mitochondrial DNA, nutritional limitation is critical for increased mortality. Surprisingly, murine Bcl-2 lacking the membrane anchor of human Bcl-2 has no effect on grande cells, but can efficiently rescue petites in rich medium. It has been suggested that the C-terminal membrane anchor of human Bcl-2 may have a crucial role in rescuing apoptosis in mammalian cells. When murine Bcl-2 is fused to the membrane anchor of yeast mitochondrial Mas70 protein, the Bcl-2 variant mBcl-2-mma rescues not only petites but also grandes, just like human Bcl-x(L). The rescuing ability of Bcl-x(L), which contains its own membrane anchor, surpasses that of mBcl-2-mma. Our results indicate that the process involving Bax-induced growth inhibition followed by possible lethality, and the rescuing effect of Bcl-2 or Bcl-x(L) is linked to yeast mitochondrial function. We propose a model which is consistent with these observations.

【 授权许可】

Unknown