Prion protein prevents Bax-mediated cell death in the absence of other Bcl-2 family members in Saccharomyces cerevisiae

FEMS Yeast Res. 2006 Dec;6(8):1204-12. doi: 10.1111/j.1567-1364.2006.00122.x.


Although there is no consensus regarding the normal function of the prion protein, increasing evidence points towards a role in cellular protection against cell death. We have previously shown that prion protein is a potent inhibitor of Bax-induced apoptosis in human primary neurons and in the breast carcinoma MCF-7 cells. Here, we used the yeast Saccharomyces cerevisiae to investigate if the neuroprotective function of prion protein requires other members of the Bcl-2 family given that S. cerevisiae lacks Bcl-2 genes but undergoes a mitochondrial-dependent apoptotic cell death upon exogenous expression of Bax protein. We show that Bax induces cell death and growth inhibition in S. cerevisiae. Prion protein prevents Bax-mediated cell death. Prion protein overcomes Bax-mediated growth arrest in S phase but cannot overcome population growth inhibition because the cells then accumulate in G(2)/M phase. We conclude that prion protein does not require other Bcl-2 family proteins to protect against Bax-mediated cell death.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Apoptosis / physiology*
  • DNA, Complementary
  • Humans
  • Mice
  • Mitochondria
  • Prions / genetics
  • Prions / physiology*
  • Proto-Oncogene Proteins c-bcl-2 / physiology
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / physiology
  • S Phase / physiology
  • Saccharomyces cerevisiae / genetics
  • Saccharomyces cerevisiae / physiology*
  • bcl-2-Associated X Protein / genetics
  • bcl-2-Associated X Protein / physiology*


  • DNA, Complementary
  • Prions
  • Proto-Oncogene Proteins c-bcl-2
  • Recombinant Fusion Proteins
  • bcl-2-Associated X Protein