Send to

Choose Destination
See comment in PubMed Commons below
J Cell Sci. 2006 May 1;119(Pt 9):1843-51. Epub 2006 Apr 11.

The inhibitor-of-apoptosis protein Bir1p protects against apoptosis in S. cerevisiae and is a substrate for the yeast homologue of Omi/HtrA2.

Author information

M. E. Müller Institute for Structural Biology, Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland.


Inhibitor-of-apoptosis proteins (IAPs) play a crucial role in the regulation of metazoan apoptosis. IAPs are typically characterized by the presence of one to three baculovirus IAP repeat (BIR) domains that are essential for their anti-apoptotic activity. Bir1p is the sole BIR-protein in yeast and has been shown to participate in chromosome segregation events. Here, we show that Bir1p is a substrate for Nma111p, which is the homologue of the human pro-apoptotic serine protease Omi/HtrA2 and which is known to mediate apoptosis in yeast. Bir1p is a cytoplasmic and nuclear protein, and yeast cells lacking bir1 are more sensitive to apoptosis induced by oxidative stress. Consistently, overexpression of Bir1p reduces apoptosis-like cell death, whereas this protective effect can be antagonized in vivo by simultaneous overexpression of Nma111p. Moreover, chronologically aged cells that constitutively overexpress Bir1p show a delayed onset of cell death. Therefore, Bir1p, like its closest metazoan homologues deterin and survivin, has dual functions: it participates in chromosome segregation events and cytokinesis and exhibits anti-apoptotic activity.

[Indexed for MEDLINE]
Free full text
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for HighWire
    Loading ...
    Support Center