BOD (Bcl-2-Related Ovarian Death Gene) Is an Ovarian BH3 Domain-Containing Proapoptotic Bcl-2 Protein Capable of Dimerization with Diverse Antiapoptotic Bcl-2 Members

Abstract

Using the yeast two-hybrid protein-protein interaction system to search for genes capable of forming dimers with the antiapoptotic protein Mcl-1, we have isolated BOD (Bcl-2-related ovarian death agonist) from an ovarian fusion cDNA library. The three variants of BOD (long, medium, and short) have an open reading frame of 196, 110, and 93 amino acids, respectively; all of them contain a consensus Bcl-2 homology 3 (BH3) domain but lack other BH domains found in channel-forming Bcl-2 family proteins. In the yeast cell assay, BOD interacts with diverse antiapoptotic Bcl-2 proteins [Mcl-1, Bcl-2, Bcl-xL, Bcl-w, Bfl-1, and Epstein-Barr virus (EBV) BHRF-1] but not with different proapoptotic Bcl-2 proteins (BAD, Bak, Bok, and Bax). After overexpression in mammalian Chinese hamster ovary (CHO) cells, BOD induces apoptosis that can be prevented by the baculoviral caspase inhibitor P35. The cell-killing activity of BOD is also antagonized in cells cotransfected with the antiapoptotic Bcl-w protein, which showed high affinity for BOD in the two-hybrid assay. Furthermore, mutagenesis studies showed that BOD mutants with alterations in the BH3 domain lose cell-killing ability, suggesting that the BH3 domain is important for the mediation of cell killing by BOD. BOD mRNA is ubiquitously expressed in ovary and multiple other tissues. The BOD gene is also conserved in diverse mammalian species. Identification of BOD expands the group of proapoptotic Bcl-2 proteins that only contains the BH3 domain and allows future elucidation of the intracellular mechanism for apoptosis regulation in ovary and other tissues.

Adeno-associated virus-mediated delivery of BCL-w gene improves outcome after transient focal cerebral ischemia

“…21,22 The molecular mechanisms through which BCL-w protein protects cells from ischemic injury remain unclear. However, cell death appears to be regulated partly by competitive interactions between pro-and antiapoptotic Bcl-2-family proteins, [23][24][25] …”

Epstein-Barr virus interactions with the Bcl-2 protein family and apoptosis in human tumor cells

“…It has three variants (long, medium, and short), all of which contain a consensus BH3 domain without the other BH domains detected in channel-forming Bcl-2 family members. In a yeast cell assay, Hsu et al (1998) found that the C-terminal BH3 domain-containing region of BOD interacted strongly with EBV BHRF1 and all known mammalian anti-apoptotic Bcl-2 proteins (Bcl-2, Bcl-xL, Bcl-w/bcl-2-2, bfl-1, and MCL-1), but not with pro-apoptotic Bcl-2 family proteins (Bok, Bax, Bad, and BAK). While studies on BOD are scarce, northern and southern blot analyses revealed that, unlike Bok, BOD is expressed in various tissues (mainly the spleen and kidney) and has been highly conserved during the evolution of mammals (Hsu et al, 1998).…”

“…Bok interacts only with EBV BHRF1, MCL-1, and bfl-1, but not other pro-apoptotic family members or anti-apoptotic Bcl-2 proteins, unlike other proapoptotic members (BIK, Bax, and BAK) . Moreover, using a direct protein-protein interaction assay in vitro, Hsu et al (1998) demonstrated that Bok-L alone, without Bok-S, interacts strongly with BHRF1. In a variety of cell types, Bok induces cell killing, but this is inhibited following co-expression with BHRF1 and MCL-1, but not with Bcl-2 or Bcl-xL (McCurrach et al, 1997;Rampino et al, 1997;Yin et al, 1997).…”

“…The Bcl-2-related ovarian death gene (BOD) was first identified as an ovarian Bcl-2-related, Bcl-2 homology (BH3) domain-only protein in an ovarian fusion cDNA library (Hsu et al, 1998). It has three variants (long, medium, and short), all of which contain a consensus BH3 domain without the other BH domains detected in channel-forming Bcl-2 family members.…”

Enhancement of thymidine kinase-mediated killing of malignant glioma by BimS, a BH3-only cell death activator

“…Bim was isolated independently by two groups that exploited its ability to bind Bcl-2 and Mcl1. 20,21 Alternative splicing of Bim gives rise to three variants, BimEL, BimL, and BimS, each of which contains the BH3 domain and functions as a death inducer. In certain cell types, BimEL and BimL, but not BimS, bind to M r ¼8000 dynein light chain, LC8 (also PIN or Dlc-1), 22,23 which negatively regulates the proapoptotic function of the former two isoforms.…”